Antihistamines

 

There is a very nice review about histamine and antihistamines in the most recent Journal of Allergy and Clinical Immunology by Drs. Simons and Simons. The review was to commemorate 100 years since the discovery of histamine as a mediator and 70 years since antihistamines have been available for clinical use.

H1 antihistamines are the largest class of medication available with >45 available. These agents act against histamine’s effect on allergic inflammation. There are two general classes of these agents- first generation and second generation. Better put, the old ones that can get into the brain and cause sedation and the newer ones that tend to not to be sedating.

The older or first generation of antihistamines became available at a time when regulations were different and because of this, there is a lack of information about how these agents are handled in a variety of special populations; children and infants specifically. The new generation of these agents has undergone rigorous evaluations. These studies have shown that tolerance does not occur with the regular use of these agents. In other words, you do not become immune to these agents.

 Antihistamines work for and are indicated for the following conditions (where they are the medications of choice);

  •  Allergic rhinitis (nasal allergy)
  • Allergic conjunctivitis (eye allergy)
  • Acute urticaria (hives)
  • Other- mastocytosis, mosquito bite reactions, immunotherapy reactions

In these three conditions, there have been hundreds of well-designed studies that support their effects. The evidence is there.

A couple of points were made;

  •  Antihistamines do not work in nasal symptoms not due to allergy
  • Some will work within 15 minutes others may begin to show an effect in 2.5 hours
  • Topical nasal antihistamines may work as good as or better than oral antihistamines for congestion
  • Hives that last longer than 6 weeks, chronic hives, may require doses 4-fold higher
  • Current guidance for chronic hives has the H2-class as the antihistamine of choice at high dose

 Conditions for which an antihistamine is not the medication of first choice;

  •  Atopic dermatitis
  • Asthma
  • Anaphylaxis
  • Nonallergic angioedema
  • Other disorders

The points made regarding these conditions were;

  •  There have been no high-quality studies to confirm their efficacy in atopic dermatitis
  • The use of antihistamines in atopic dermatitis is still sometimes used for sedation effects (which would be the first generation antihistamines).
  • A review of 2070 studies on the use of antihistamines with anaphylaxis could not identify a good study that provided solid evidence for the use of these agents in anaphylaxis. They decrease itch and hives. They do not prevent or relieve airway/throat swelling.
  • The efficacy of antihistamines to treat colds, ear infections, sinus infections, nasal polyps, nonspecific cough, nonspecific itching has not been confirmed in well done studies.

 Conditions for which the first generation antihistamines have been used;

The first generation antihistamines have been used in a variety of conditions, however the evidence to support their use is considered weak. Most of these conditions involve the central nervous system;

  •  Insomnia
  •  Conscious sedation
  •  Perioperative sedation
  •  Analgesia
  •  Anxiety
  •  Serotonin syndrome
  •  Akathisia
  •  Migraine
  •  Motion sickness
  •  Vertigo

 Reviewer’s note-

Antihistamines are one of the most frequently used agents and have been used for a variety of conditions. They work for some things and not for others. I have seen multiple antihistamines used in the same child and choices made for perhaps the wrong reasons. Also of note is to keep in mind that when a study is done, there are responders and non-responders. Sometimes there are not enough responders to show a significant difference. The conclusion from such a study could be that the agent does not work and would not be recommended overall. A question to ask is whether it had an effect in anyone or was it a total non-response?

The take home messages for me- when they stop working think of some non-allergic issue, tolerance does not develop. If you use these for atopic dermatitis, you are looking for sedation. It would make more sense to go with the first generation agents in this condition. In conditions that do not respond, the dose may need to be increased as opposed to adding a second agent. Don’t ask more of the antihistamines than they can deliver.

 

FEL (December 24, 2011)

 

December 24, 2011 · fleickly · No Comments
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Indy’s Child- Peanut Allergy Post

 An article, Understanding Peanut Allergies: Considering the factors before you become peanut-free, appears in this month’s Indy’s Child. I was interviewed for a program called ‘Riley Speaks’ and this was a topic of great interest.

A few things to add. I prefer the use of the term ‘peanut-safe’ in deference to ‘peanut-free’. The terms safe and free may have the same intent, however they may be practiced differently. For example, peanut free would mean that no peanuts would pass through the threshold of the institution- that is the policy, that is the law. Now consider ‘peanut-safe’. When you are peanut-safe, it includes the previous concept and adds the idea of continued vigilance; always checking, always looking, being active about keeping peanuts away from those who may have life-theatening events with exposure.

The other item I would add is that at this time, since I write all the material for allergy at Riley, you would have to check out this website for more information. The www.RileyHospital.org gets you to the children’s hosptial website and how to access the children’s hospital. They are working on topic postings.

Thanks for looking,

Fred Leickly (12-11-2011)

 

 

December 11, 2011 · fleickly · No Comments
Posted in: Allergies, Allergy in Children, Food Allergies, Interesting articles, Peanut Allergy, Pediatric Allergy

Egg Allergy and the Flu Vaccine

A notice today has taken a significant amount of uncertainty regarding egg allergy and the flu vaccine. We have seen a number of changes over the past few years. The flu vaccine-egg connection is going down the pathway that the MMR vaccination has taken.

The most recent recommendation is that all children should get the flu vaccine regardless of egg sensitivity or egg allergy. Skin testing to the vaccine and the use of split doses is no longer recommended. If the history is egg anaphylaxis, the vaccination should be performed in the allergist’s office.

Details from the recommendations written by Drs. Kelso, Li, and Greenhawt are available.

FEL

12-1-2011

December 1, 2011 · fleickly · 2 Comments
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A Great Day in the Clinic

Today was an exceptional day in the Allergy Clinic. I see three new patients in my afternoon session. Today, two of the three children had problems that I had published on and one had something that I also struggle with.

During my fellowship in allergy, I worked with family in which 7 boys were affected with X-linked agammaglobulinemis. I published a paper about their interesting presentations. One of my kids today had this condition and a number of associated problems. It was refreshing and hopefully helpful to the family who was here to see me about possible allergies.

The next was a young man of 12 years who had over the past year complaints of a scratchy throat, itchy mouth, and a garbled voice after eating watermelon. It also happened with banana, grapes, avocado, and cantelope. This is the oral allergy syndrome. I struggle with this too. My reaction to watermelon prompted one of our allergy fellows at Henry Ford Hosptial to do a research project on the problem. That work also resulted in a publication.

So two of my three patients today had clinical problems that I had written about and had published on.

It was a great day indeed.
FEL

December 1, 2011 · fleickly · No Comments
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Skin Testing for Aeroallergens

Position Paper:

Practical guide to skin prick tests in allergy to aeroallergens

I was alerted to this article by my partner Dr. Vitalpur. It comes from Allergy (European Journal of Allergy and Clinical Immunology) 2011 . The purpose of the article was to provide ‘pocket guidelines’ from a consensus report regarding the use of allergy skin prick tests for inhalant or aeroallergens.

The skin prick test (SPT) is a widely used, major diagnostic tool used for the diagnosis of allergy. The introduction of the article points out the many complexities in performing SPTs and recommends that they should be performed only by trained health professionals.

As for the methods used to create the guide; it was a combined effort from the Global Allergy and Asthma European Network (GA2LEN) and the Allergic Rhinitis and its Impact on Asthma (ARIA) task force. Once the document was created, it was reviewed by the membership of the networks. The authors point out that this is not an evidence-based guideline. It should be looked at as ‘…clear-cut answers to frequently asked questions by practitioners and patients.’ The evidence-based aspect follows the guide-in future reports.

The article is broken down into a series of 21 specific questions:

  1. What are the indications for skin tests in clinical practice?
  2. Which skin tests are recommended?
  3. What role do intradermal tests play?
  4. What is the recommended skin prick test technique?
  5. Which treatments suppress skin tests?
  6. Which diseases affect skin tests?
  7. Which allergen extracts to choose?
  8. Which allergen extracts should be tested?
  9. What area of the body should be chosen and what is the ideal distance between tests?
  10. Which negative and positive controls are recommended?
  11. Which results are regarded as positive?
  12. How do skin tests compare with serum-specific IgE?
  13. How to interpret skin test results?
  14. Which skin tests are recommended in adolescents and adults?
  15. Which skin tests are recommended in the elderly?
  16. Which skin tests are recommended in young children?
  17. What is the role of skin tests in primary care?
  18. How can skin tests be used in developing countries?
  19. Are skin tests needed in allergen immunotherapy follow-up?
  20. Can skin tests be used in research?
  21. What are the future needs?

Each question has a short, concise answer. These are common concerns and questions. I would like to point out a few of them for this review. The link will direct the reader to questions not covered here.

1. What are the indications for skin tests in clinical practice?

Asthma and allergic rhinitis are the indications for aeroallergen testing. The SPTs can be used from infancy to old age. The repeating of SPTs is done to detect new sensitizations in children and when changes in symptoms have occurred. 

2.Which skin tests are recommended?

Prick skin tests have a high degree of correlation with symptoms. There is high specificity (a negative test when you do not have the disease) and sensitivity (when the test is positive when you have the condition) with the skin pricks used for inhalant allergy.

 Table 1 Performance of skin prick tests

  1. Use standardized extracts when available (We have grass, house dust mites, and cat as standardized extracts.)
  2. Include a positive and a negative control solution (histamine is the positive control)
  3. Perform tests on normal skin (not on skin affected by severe eczema or urticaria)
  4. Evaluate the patient for dermatographism (Means skin writing- pressure to the skin will cause a hive, this is a common reason for someone to allergic to everything including the negative control.)
  5. Determine and record medications taken by the patient and the time of the last dose
  6. Record the reactions after 15 minutes
  7. Measure the longest wheal diameter

Skin prick testing may cause systemic reactions

The common errors in skin testing are listed in table 2

  • Tests are placed too close together and overlapping reactions cannot be separated visually.
  • Induction of bleeding, leading possibly to false-positive results.
  • Insufficient penetration of the skin by the puncture instrument, leading to false-negative results. This occurs more with plastic devices.
  • Spreading allergen solutions during the test or when the solution is wiped away.

 3. What role do intradermal tests play?

Intradermal skin tests (when a needle is used to inject the extract- almost like a TB test) are not useful for allergy diagnosis with inhalant allergens. The clinical value is unknown in patients who only have positive intradermal tests. They are less safe to perform. There are practices where this is the only type of test done or they are performed when the SPTs are negative. We use this type of test ONLY in the ‘Bee Clinic’- the protocol for pursuing stinging insect allergy utilizes the intradermal test.

4. Which treatments suppress skin tests?

Drugs can suppress skin tests.

 Antihistamines- have a significant impact on skin test results. They should be avoided for 7 days

Imipramine- anti-depressants, sometimes used for bed wetting- can affect skin test results for 21 days

Steroid ointments and creams- minimal if any effect on skin testing

UltraViolet light – used to treat skin condition, can effect skin test results for up to 4 weeks

Table 3 Inhibitory effect of various treatments on skin prick tests show other agents that may impact skin test results.

5. Which diseases affect skin tests?

Patients with widespread eczema or hives cannot be tested in areas of affected skin. Neurological disorders and infectious diseases (e.g. leprosy) can lead to false-negative results.

6. Which allergen extracts to choose?

The quality of the allergen extract is of key importance as variations in the quality and/or potency of commercially available extracts exists, in particular for animal mites, animal dander, and molds, but even pollens. Use standardized extracts if available.  

7. Which allergen extracts should be tested?

This varies per region. This answer was relevant to Europe. I comment on this at the end of the review.

 8. What area of the body should be chosen and what is the ideal distance between tests?

Usually, the skin tests are performed on the forearms depending on the age of the patient. The distance between tests should be 2 cm. We have used the child’s back for testing. There is a larger surface area to work with. If needed, more items could be evaluated using the larger space. It is also an area which would not be frequently treated with a topical steroid.

 9. Which results are regarded as positive?

The wheal and erythema have been used to assess the positivity of the skin test. However, only the wheal is needed. The largest size of the wheal is considered to be sufficient. Wheal diameters equal to or larger than 3 mm are considered positive in SPTs.  

Redness alone is not a significant response. There needs to be a wheal (swollen area) of proper size to be called significant. In our clinic, the physician who ordered the test reads them and decides on the significance. All too often, slight red marks are interpreted as positives.

 10. How do skin tests compare with serum-specific IgE?

Serum-specific IgE, SPTs and allergen challenge do not have the same biological and clinical relevance and are not interchangeable. Low levels of serum-specific IgE are less often associated with symptoms than higher levels, but they do not exclude allergic symptoms particularly in very young children.

Note- the paper did not use the term RAST. The proper term is serum-specific IgE- that blood test for allergy. I thought that the answer to this question was not as complete as it should have been.

 11. Are skin tests needed in allergen immunotherapy follow-up?

Skin test reactivity decreases with allergen-specific immunotherapy to inhalant allergens, but skin tests cannot be used to assess the efficacy of immunotherapy in practice. Moreover, skin tests cannot be used to decide the cessation of immunotherapy.

Reviewer’s Comments-From the original 21 questions, I chose 11 that tend to be more frequently brought up in our practice. Many of the questions that I omitted dealt with issues unique to Europe or to the adult population.

In a nutshell the skin prick tests for aeroallergens (inhalant allergens) are:

  • Indicated for respiratory tract symptoms
  • Can be done in very young children
  • Should be done with the proper extracts and application technique
  • Can be done if a few medications are out of the child’s system
  • There may be a problem finding clear skin to do them on a child who has eczema or hives
  • May be done on the arms,
  • Are considered positive if the wheal (swollen area) is of proper size (redness alone does not qualify)
  • Should not be used to monitor an allergy shot program.

This was a very neat, concise, and well done synopsis of how things are done in Europe. An additional tidbit was the answer to the question- Which allergens should be tested? The quick answer is that it depends on the allergen exposure for the area and that a common, standardized battery of tests should be recommended for Europe. The list was short;

  • Pollens- Birch, Cypress, Grass (one species or a mix), Mugwort, Olive (or Ash), Parietaria, Plane, and Ragweed
  • Mites- two species
  • Animals- Cat and Dog
  • Mold- Alternaria and Cladosporium (Aspergillus extract is not available in all countries).
  • Insects- Cockroach

That panel for respiratory tract allergens would contain only 15 aeroallergens plus the two controls- 17 skin tests done to assess allergen sensitization.

A reference was also made to the National Health and Nutrition Examination Survey (NHANES) performed in the United States (2005) – 10 allergens were used.

FEL

11-30-2011

November 30, 2011 · fleickly · No Comments
Tags: , , ,  Â· Posted in: Allergies, Allergy in Children, Allergy Testing, Article Review, Asthma, Environment, Interesting articles, Nasal Allergy

Top Docs

My most sincere thanks to my peers for being nominated as a ‘Top Doc’. The November issue of Indianapolis Monthly has the listings and specialties. Congradualations to Dr. David Patterson who was also recognized in the field of allergy/clinical immunology. The listing includes 352 physicians in 56 different specialties. I have had this honor since 2003 (2003, 2005,. 2007, 2009. 2010, and 2011). Wow! I must be doing something right.

The listings include a few special areas of expertise. For me it is asthma, atopic dermatitis, and food allergy. The most common reason for a visit has been food allergy. Nasal allergy is number two, followed by asthma. I keep track of these things. It always of interest to note all the varied reasons to seek an allergy consultation.

Please note that the phone number provided (317-274-7208) is for my main office.

Fred Leickly

 

October 27, 2011 · fleickly · 4 Comments
Tags:  Â· Posted in: Indianapolis Monthly Top Doctors

Oral Food Allergy Challenges

This is a very interesting article on food allergy. It involves the use of diagnostics used to declare ‘food allergy’ and how this declaration of a food allergy can be verified by doing a food challenge. This work was performed at National Jewish Hospital in Denver, Colorado. The reference for this is - Oral Food Challenges in Children with a Diagnosis of Food Allergy.  David M. Fleischer, Alan Bock, Gayle Spears, Carla Wilson, et al. Journal of Pediatrics 2011;158:578-583. Note that the link is to a synopsis. The article can be viewed if you are a subscriber to the journal, you have a medical library connection, or it can be purchased.

Usually when I review an article I go directly to that part of the introduction that deals with the purpose of the study. However, the background information provided in the introduction I thought was very helpful in understanding food allergy, noting the concerns regarding food allergy, and sharing how experts in the field of food allergy handle it (especially as they see a significant number of food allergic children in their referral center).

Identified problems with food allergy;

  1.  Availability of serum IgE tests for foods
  2.  Use of allergy tests to direct avoidance diets
  3.  Consequences of avoidance diets
    • Poor weight gain
    •  Malnutrition
  4.  Idea that food allergy is the exclusive cause of atopic dermatitis
  5.  Food allergy focus leads to neglect of skin care

The allergy test result, whether by skin prick test or by serum IgE (formerly known as RAST) antibody levels, predict the chance of having a reaction with exposure to that food (they also demonstrate the presence of IgE directed against that food). These probabilities have been established for just a few foods; cow’s milk, hen’s egg, fish, peanut, and tree nuts. For all the other foods the levels that predict the chance of the child having a positive reaction have not been established.

Another significant issue that clouds the picture is that both allergic skin testing and serum specific IgE levels obtained from a blood test frequently detect sensitization that is not associated with any symptoms when the food is ingested. The false positive rate- when the test is positive and the story is that there were no problems with ingestion – is 50%! The gold standard for a food allergy is the double-blind placebo-controlled challenge. In other words, the best indicator is the history- what happens when the food is ingested.

The Purpose of the Study- was to raise awareness about the overreliance on serum immunoglobulin results as the primary indicator for establishing a food elimination diet in children (with atopic dermatitis).

Methods-This was a retrospective chart review of children who were seen for atopic dermatitis and food allergy. The number evaluated was 125.

Results

The median age of the children was 4 years. Most of had atopic dermatitis (96%). The severity of the atopic dermatitis varied- 30% were mild, 24% were moderate, and 42% were severe.

There were 364 oral food challenges performed on foods that were avoided at the time of the evaluation. That is almost 3 food challenges per child. Most of these challenges were negative- 325/364 (89%). Of note that during these food challenges, if there was a reaction, it occurred within a 2-hour observation period. Also, there were no documented flares of the skin condition.

Those 364 food challenges occurred in three different groups of children; 111 in whom foods were avoided due to a positive allergy test, 122 in whom a food was avoided due to a previous reaction to a food, and the last grouping was 131 children in whom a food was avoided for other reasons (not a history of a reaction or a positive allergy test). This last group included those who avoided a food because of lack of prior exposure, another family member with an allergy to that food, parental fear, refusal to eat the food, worsening of atopic dermatitis was uncertain with exposure, being too young for the food, and uncertain reasons.

In the group who avoided a food due to a positive allergy test (n=44 children) – with wheat being an exception (at 77% negative), 80% or more of the food challenges were negative. When there was a positive food challenge, the foods involved included egg, banana, peanut, soy, and wheat.

There were 122 food challenges done in a group of children (n=67 children) who had a history of a reaction to the food. When peanut and oats are excluded, more than 75% of the food challenges were negative. The positive food challenges were to; egg, chicken, milk, oat, peanut, soy, pea, wheat, beans, and pork & beans. This group of children had an array of food reactions by history; anaphylaxis (5%), gastrointestinal reactions (17%), lower respiratory tract reactions (8%), upper respiratory tract reactions (10%), and skin reactions (76%).

In the last group, those who avoided a food for other reasons, (n=131) more than 90% of the challenges were negative. There were 11 positive food challenges. The positive foods included egg, fruits (strawberry), meats (beef, chicken), milk, shellfish (shrimp), soy, barley, and Alimentum.

The levels of specific IgE antibody to the food were used to divide those who were challenged versus those who were not challenged. The following table shows the serum IgE level, the offering of a food challenge, and the result of the food challenge. When the serum IgE levels were elevated, no challenges were offered. For these three foods everyone who was below the critical cut-off point passed the food challenge. The decision levels for doing a food challenge were as follows- egg:< 2years of age -2 kU/L and >2 years of age 7 kU/l, Milk:< 2 years of age -5 kU/L and > 2 years of age a5 kU/l, peanut: 14 kU/L.

               

Food Specific IgE Food Challenge No Food Challenge Yes Challenge Positive Challenge Negative
Egg n=11 >68.9+/-38.9 11 0 NA NA
Egg n=6 1.9+/-1.3 1 5 0 5
Milk n=5 >44.7+/-22.7 3 2 0 2
Milk n=5 2.2+/-2.8 0 5 0 5
Peanut n=15 >77.3+/-27.6 15 0 NA NA
Peanut n=9 2.9+/-3.5 5 4 0 4

 

84-93% of foods that were avoided for a variety of reasons were returned to the child’s diet after a successful food challenge.

Conclusions- the authors concluded that in the absence of a history of anaphylaxis, the primary reliance on serum food-specific IgE testing to establish the need for a food elimination diet is not sufficient, especially within the population of children with atopic dermatitis. Oral food challenges are indicated to confirm the presence of a food allergy.

Many of the children seen were on overly restrictive diets that were inclusive of foods they never had exposure to or foods that were eaten without a problem. This restriction was based on food blood test results. The successful food challenge demonstrated that specific food restriction was not necessary in most instances. A food challenge discerns sensitization from true allergy.

The authors point out that it is important to optimize skin care and clearing to accurately sort out the impact of a food on the condition. It is also stated that there is a significant overreliance on allergy test results in making the diagnosis of food allergy especially in the children with atopic dermatitis. Allergy test results, if not supported by a food challenge, can lead to unnecessary food restrictions. To quote the authors, ‘misinterpretation of food allergy immunoassays, for which there is no correlation between the level and the probability of reacting to a food, is leading       unnecessary dietary restrictions that could result in nutritional deficiencies.’

Reviewer’s Comments- After my first read of the article, I felt that this was a very strongly worded statement against the indiscriminate use of serum IgE testing.  After numerous reads, that opinion of the article has not changed. This work is a strong statement against serum IgE testing for allergy.

It is important to point out that the vast majority of children who were in the study had atopic dermatitis (aka eczema). This clinical condition is notorious for having many false positive food allergy tests. During the 1980’ there were many studies that linked food allergy with atopic dermatitis. During my fellowship at Duke we watched children with severe atopic dermatitis react during the double-blind placebo-controlled food challenges. These studies led to the observation that there were 6 foods commonly associated with the condition; egg, milk, wheat, soy, peanut, and fish. Subsequently, many children with a range of presentations of atopic dermatitis have undergone allergy testing both by the skin prick method and by serum testing.  That has led to the concerns presented in this article.

The current ‘state of the art’ noted in the NHLBI Guidelines for the Diagnosis and Management of Food Allergy  suggests that food allergy considerations should include egg and any other food that the family feels is causative to the skin condition.

The authors point out that the availability of immunoassay food allergy panels to identify possible food allergy has added to the ongoing potential for misinterpretation of the results.

We also have that issue that continuously plagues us- sensitization vs. allergy. The laboratory test tells us that IgE is being made. The significance of that IgE has to be determined by the clinician. Taking a history is one way to begin establishing significance. The food challenge would be the bottom line for establishing relevance and significance of a positive IgE test for a food.

There are many messages within this study. The concerns regarding restrictive diets and avidly pursing food allergy diagnostics can lead to;

  1. Failure to thrive due to food restrictions
  2. Parental perceptions about unclear messages about which foods must be avoided
  3. Attempts to treat atopic dermatitis by diet alone and not proper skin care
  4. Pressure from parents to get these blood tests for food allergy
  5. Incomplete understanding about the class designations
  6. Applying the well-established food specific IgE values to foods that have not been rigorously evaluated

These concerns are seen with parents, primary caretakers, and yes, even allergists.

 When an allergy test for a food is positive yet the food is eaten without any clinical reaction, the test was a false positive. We should not let the laboratory result dictate the care of the child. Specific food allergy testing can be done for the food of interest. Select the test based on the story that supports it.

I think the role of the allergist in the near future will be to clear many of these positive tests. Here at Riley hospital we have an extensive experience in doing food challenges. Most of the time we perform a food challenge to demonstrate that a food allergy has been outgrown. We offer them in a controlled clinical environment. Everything is in place to take care of a reaction. In the near future I am sure we will be doing more food challenges to demonstrate the irrelevance of positive allergy test results.

The serum tests for IgE to food have helped with the decision to offer a food challenge for some foods. I look to the serum tests for food to decide the chance of a reaction and whether or not an oral food challenge should be scheduled. It is always perplexing to have a child present who has had a panel performed. All too often we struggle with results deemed high due to the ‘H’ notation after the specific concentration. We struggle with positive results from foods that the child has never ingested. We very frequently struggle with results on foods that the child has eaten with impunity and never had a problem. The food challenge helps to sort the well from the worried well.

Many times I have witnessed the joy of having the yoke (not yolk) of a food allergy removed by doing the food challenge.

FEL

October 4, 2011 · fleickly · 6 Comments
Tags: , ,  Â· Posted in: Allergies, Allergy in Children, Allergy Testing, Food Allergies

Influenza Vaccine and Egg Allergy 2011-2012 Season

In the recent editon of the American Academy of Pediatrics (AAP) News (AAP News September, 2011) there is an article on the influenza vaccine recommendations for this upcoming ‘flu’ season. It mentions the precautions that need to be taken when egg allergy is part of the child’s story. This article had a very nice algorithm. This is an area of change. As our experience grows in vaccinating egg-sensitive children with egg-containing vaccines the recommendations will change. What follows is from the AAP. The recommendations are from the AAP Committee on Infectious Diseases, Dr. Bernstein was the author.

“Most children with a history of a mild egg allergy (defined as hives) can receive the influenza vaccine safely in the office without the need of an allergy consultation.”

That conservative approach with skin testing, desensitization, or challenge dosing are not recommended. There are however a few precautions-

Resuscitative equipment must be readily available in the office

Those who have an egg story should be kept in the office for 30 minutes after the immunization is given

For those who need a second dose, the same product/brand is preferred if possible, it does not have to be of the same lot.

An allergy consultation should be asked for any child who has a severe reaction to egg. That severe reaction is defined as a reaction that involves the cardiovascular system, the respiratory tract, the gastrointestinal tract, or any child who needed epinephrine for a reaction to egg.

The algorithm is as follows-

It is important to protect our children from the ‘flu’. These new recommendations should make it easier for those who have struggled with a diagnosis of egg allergy and the need for a ‘flu’ shot. One situation that we are frequently asked about is what to do about those children who have a positive allergy test to egg and no history of exposure to egg? It would be great to see that statement here in this AAP guidance. However, the decision point stands- does the child have a history of an allergic reaction to egg- it does not ask if the child has a positive allergy test to egg. Again, the history of a reaction with exposure is what separates the allergic child from the sensitized child. My take on this is to let the history of clinical egg reactions dictate the determination of severity. In the truly nervous situation, the 10/90 may help get the family through this. Often times the allergist could take care of these situations for the primary caretaker. What helps is for us to know comfort levels on behalf of the referring physicians and the families. With accumulating evidence over the past year regarding egg allergy and this vaccination, I think next year’s recommendations will even more liberal.

FEL (September 2, 2011)

September 2, 2011 · fleickly · 2 Comments
Posted in: Uncategorized

Food Allergy Epidemiology- Prevalence, Severity, Distribution, and Disparities. A Review.

Food Allergy Epidemiology in the United States

The July issue of Pediatrics has an article entitled, ‘The Prevalence, Severity, and Distribution of Childhood Food Allergy in the United States’ by R S Gupta, E E Springston, M R Warrier, B Smith, R Kumar, J Pongracic, and J L Holl. The bottom line from this work is that the prevalence and severity of food allergy is greater than previous reports would indicate and this was a fairly large nationwide survey designed to address the question of prevalence. The authors also conclude that disparities exist with the clinical diagnosis of the condition.

Purpose of the paper- to determine the prevalence, severity, and distribution of food allergy in children.

Methods-The authors created a survey that was population-based and cross-sectional. It was administered to a representative sample of the United States population between June 2009 and February 2010. This survey was carefully developed and evaluated prior to its use. It was not a previously used, standardized tool.

Recruiting and survey administration was performed by a survey research company. Internet access was required to participate.

Completion of 40,000 surveys would give the study significant power (0.9) at a significance level of 0.5 to detect overall and allergen-specific food allergy prevalence (between 1-9%) and prevalence variability from 1-7% in groups as small as 1% of the sample.

Outcome Measures

The primary outcomes were food allergy prevalence and severity.

Food allergy was defined as a report of a confirmed or a convincing story of an allergy.

A convincing food allergy was based on at least one of the following;

  1. Anaphylaxis- defined as a severe reaction that could lead to death

  2. Angioedema (swelling) of the lips, eyes, or face

  3. Other Angioedema

  4. Coughing

  5. Other oropharnygeal symptoms

  6. Eczema

  7. Flushing

  8. Hives

  9. Low blood pressure

  10. Pruritis (itching)

  11. Trouble breathing

  12. Vomiting

  13. Wheezing

A confirmed food allergy had the above criteria and included a report of a physician-diagnosis with serum-specific IgE, skin prick test results, or the result of an oral food challenge.

The severity of a food reaction was based on the nature of the symptoms;

Mild-moderate food allergy symptoms were limited to;

  1. Angioedema of the lips, eyes, or face

  2. Other angioedema

  3. Coughing

  4. Other oropharyngeal symptoms

  5. Eczema

  6. Flushing

  7. Hives

  8. Pruritis

  9. Vomiting

Severe food allergy symptoms were;

  1. Any report of anaphylaxis

  2. Low blood pressure

  3. Trouble breathing

  4. Wheezing

  5. Vomiting and angioedema, and coughing in combination

Results

The final sample size was 38,480 children.

The prevalence of food allergy in children was 8%. Multiple food allergies were reported in 2.4% (approximately 1/3 children of those with food allergy had more than one food to report).

Allergen prevalence was as follows;

Peanut- 767/3339 (23% of the reports) 52% had severe reactions, 48% had mild-moderate reactions

Milk- 702/3339 (21% of the reports) 31% had severe reactions, 69% had mild-moderate reactions

Shellfish- 509/3339 (15% of the reports) 47% had severe reactions, 53% had mild-moderate reactions

There was an age variation reported (the highest percentage reporting a specific food allergy);

Peanut- 30% in the 3-5 years of age group

Milk- 32% in the 0-2 years of age group

Shellfish- 24% in the > 14 year old age group

Tree nuts- 15% in the 11-13 year old age group

Egg – 16% in the 0-2 year old age group

Fish (fin) – 7% in the >14 year old age group

Strawberry- 8% in the 0-2 year old age group

Wheat- 8% in the 11-13 year old age group

Soy- 7% in the 11-13 year old age group

Severity of the Food Reactions

The prevalence of a severe reaction to a food was 3.1% of the surveyed population. This translates to 38.7% of the food allergy population. These severe reactions were reported more frequently in the children who had peanut or tree nut allergy. From the note above- 52% of the peanut and 53% of the tree nut allergic group had severe reactions.

When it happens to you or your child- it is 100%. The reassurance factor- just over 1/3 have serious reactions, most do not. Serious reactions are seen just over half the time with peanuts and tree nuts.

Food Allergy Associations- Odd/Risk Factors

The odds of having a food allergy were-

  1. Higher in Asian and black children as compared to white children.
  2. Higher in all age groups compared to children aged 0-2 years.
  3. Higher in geographic areas outside the Midwest.
  4. Lower with household incomes <$50,000.
  5. Gender did not make a difference
  6. Higher for a confirmed food allergy compared to a convincing food allergy history in those children with multiple food allergies.
  7. Lower for confirmed food allergy in Asian, black, and Hispanic as compared to white children.
  8. Lower for confirmed food allergy in households with incomes <$50,000.
  9. Higher for a severe reaction among children in all age groups compared to children 0-2 years of age,  boys compared to girls, and those with compared to those without multiple food allergies.

Conclusions

Eight percent of children have food allergy with 38.7% having a severe reaction and 30.4% having multiple food allergies.

The disparity regarding food allergy diagnosis was seen with race, age, and income.

Reviewer’s Comments

Prevalence refers to the proportion of individuals with the clinical condition in a population at a specific moment in time. It provides an estimate of the risk or probability that an individual will have the condition. This would be the number of cases divided by the total population at a given moment.

When looking over the information there are a few points that need to be stressed. First was the sample truly representative?

The study was not performed on the entire pediatric population of the United States. The population was recruited from 6100 participants through a Web-enabled panel and an additional 33,900 came from on online sample of households with children; they all had access to the internet. This specific population is reported to be representative of U.S. households with children. So the first concern has been answered. However, a question arises as to selection bias. Do families who have children with food allergy have more computer access? Did the lack of computer (internet access) lead to non-selection for the study?

The second point was the definition of a food allergy. This was by the family’s report of a reaction or a confirmed food allergy. This was not a medical record review nor was this a bone-fide food challenge. The authors do point out that another bias; recall bias may be at work.

This was the largest study conducted looking at food allergy prevalence- a uniqueness to the work.

The article points out a number of helpful ‘between the lines’ points. About half of the children with a peanut allergy had a severe reaction. You can have mild-moderate reactions to peanut. The same relationship was seen with shellfish allergy.

The authors used multiple logistic regression models to establish odds. This statistical tool looks at the degree of association between having the condition after adjusting for factors that may be confounding. When the odds equal 1, then there is no increased/decreased relationship. When confidence interval include the number one, then there is no strong statistical difference. There seems to be a tendency for disparity, however I would be cautious due to the stated confidence intervals. The disparities that look clear are

Race- Asian, Black for having food allergy

Less confirmed vs. convincing cases with Asians

Age-compared to two year olds, more food allergy in all other ages

Age- compared to two year olds, more severe food allergy in all other age groups

Income- household income lower than $50,000 was protective for having food allergy, for having fewer confirmed vs. convincing histories, and having less severe food allergy. (In these instances the odds was less than one)

Geographic regions- compared to the Midwest, there was more food allergy in the Northeast, South, and West.

As for summarizing discrepancies in a few sentences- if the child was Asian or Black there was a higher chance of having food allergy, and less of a chance that it was confirmed if the child was Asian. Children over the age of two years have more reported food allergies and they tend to be more severe in the older age groups. If your family made less than $50,000, there was less of a chance that there would be a food allergy (poverty protects?). Lastly, there is less food allergy in the Midwest that in other regions of the country.

I enjoyed reading and reviewing this article. As with many good studies it stimulates more questions.

Respectfully submitted,
FEL

July 28, 2011 · fleickly · One Comment
Tags: ,  Â· Posted in: Allergies, Allergy in Children, Food Allergies, Peanut Allergy

Asthma Burden Report- Indiana

You can download the ‘2011 Asthma Burden Report’ for our state (Indiana) and see what is going on in the world of asthma viz Indiana. I have a vested interest in asthma and have been a part of many community/public health initiatives regarding asthma. As such I have always been interested to see what is happing with asthma and if any of our efforts to manage this chronic condition have made any difference.

The document I am going to review is ‘2011 Burden of Asthma in Indiana’ from the Indiana State Department of Health (ISDH).

Writer’s note- as I reviewed this I got confused and I was not sure what year I was looking at. The same concerns may occur with your reading. The basis for the confusion is that this is the 2011 Asthma Burden Report. The first sentence in the Introduction says it is the 2010 Indiana Asthma Burden Report, yet all the data is 2009? Since it takes time to collect information and to run an analysis, my guess is that this is the Burden of Asthma in the State of Indiana in 2009 with some 2007 information included. Just watch the dates on the data.

A few facts regarding asthma in Indiana-in children;

  • Asthma is the third leading cause of hospitalization for children under the age of 17 years.
  • In 2009, an estimated 150,000 children (9.9%) reported currently having asthma.
  • Nearly 15% of children reported having been diagnosed with asthma at some point during their lifetime.
  • Nearly 24% of high school students reported having asthma at some time in their lives and 12.2% reported having current asthma in 2009.

The information in the report comes from a questionnaire, the Behavioral Risk Factor Surveillance System (BRFSS). This is a telephone survey. Using 2009 (the ISDH website as of 5-23-2011), there were 9,288 randomly selected individuals who were called and asked to participate. The response rate was just over 47%. What follows is asthma information for the state of Indiana regarding children (17 years of age or younger) from the BRFSS 2009 and a few interesting points regarding the entire sample.

            Since 2007 the lifetime and current rates of asthma have increased significantly. The prevalence of lifetime asthma is close to 15% and is above the national average for the year 2009. The prevalence of current asthma is also higher than the national average in 2009 (just under 10%). 

            The hospitalization rate for asthma (age-adjusted) has increased since 2007 and is 13.9 hospitalizations/10,000 residents in 2009.

            Age-adjusted emergency department visits for asthma have increased significantly since 2004; 30.4/10,000 residents to the 2009 rate of 49.7/10,000.

            Asthma mortality- death due to asthma is rare and are below national averages and continues to decline (end point was 2007).

            The highest rate of hospitalizations in Indiana was found among boy’s ages 0-4 years – 36.5/10,000 residents. Boys tended to have higher hospitalization rates until age 14 years at which time girls and women had significantly higher rates of hospitalization. Emergency department visits followed the same trend- more seen in boys less than 15 years of age then females more than males after age 15 years.

            Asthma can and does affect people of all races and ethnicities. This information was not broken down for children. The report is only on adults but does show which groups tend to be more or less affected. Hispanic adults had the lowest rate of asthma prevalence at 4.3% as well as the lowest rate of emergency department visits and hospitalizations. The white population had a prevalence of 9.2% and the black population had 12% asthma prevalence. Hospitalization occurred three times more often in the black population when compared to the white population.

            The report also looked at income, education, and geographic variation (county prevalence).

            There is a very interesting page on risk factors or behaviors associated with asthma. This however is not from 2009. This is information from the 2007 BRFSS. The following is a selection from that 2007 listing of behaviors reported by adults with asthma in Indiana.

  • 40% were advised about changing the environment
  • 10% had seen, smelled, or suspected mold in their environment
  •   4% had seen cockroaches
  •    5% had seen mice/rats in their homes
  •  20% used a house dust mite cover on their bedding
  •  80% had carpeting or rugs in their bedrooms
  •  27% used a dehumidifier to reduce moisture
  •  34% used an air purifier
  •  57% had pets
  •  28% had someone smoke in their home within the past week
  •  29% were smokers

Writer’s note; look at all the allergy potential in this listing. Allergen triggers for asthma would include mold, roach, mice, dust mites, and pets.

Protecting them against asthma. This also comes from 2007 and deals with adults with asthma.

  • 69% reported on getting instruction on how to recognize signs of an attack
  • 77% were taught what to do during an asthma attack
  • 33% received an asthma action plan
  •   6% had taken a course on how to manage asthma

Health Interventions

            The document lists a number of endeavors out there to help with education including the ISDH Asthma Program and the Indiana Joint Asthma Coalition (InJAC).

 

 Reviewers Notes

These reports are notable. My tendency is to pick away at details and ask questions. There is a wealth of information within the report, however it can be confusing and sometimes it is not totally clear why something appears and for what year. A suggestion would be to make sure the reader knows the ‘when’ of the information- 2011, 2010, or 2009, or even 2007. You can see this report on the ISDH website. There are links to background information. However, the final document should be considered a ‘stand alone’ document and should mention the methodology and specifics of the population. I was also not clear about information that clearly was not from 2009. There were presentations of information from 2007. Was this new for a burden report? Was this a re-iteration from a past report? These reports follow a format; Introduction, Goals, Trends, Disparities, Risk & Protective Factors, Conclusion, Resources, References, and Appendices. Was all the information available from the 2009 BRFSS? Will we see 2009 data later? There should have been some explanation as to why the timeline skipped around so much. That would have been very helpful for this reader.

This is the state of asthma within our state. Clearly more needs to be done. There is clearly more ‘asthma’ out there. We are higher than the national average for children. There are more emergency department visits for asthma. There are a number of possible allergy issues involved.

The ISDH has a state asthma plan and a partner organization InJAC that is looking for interested partners to help make a difference. Checkout the InJAC website and join us.

FEL

May 24, 2011 · fleickly · No Comments
Tags: ,  Â· Posted in: Asthma, Indiana Asthma Burden Report