Hives (Urticaria)

“Children who suffer from hives, especially chronic hives deserve all the sympathy, support, and empathy that those who care for them can muster. It is difficult to share the discomfort, disability, and emotional distress caused by hives to those who have never experienced this condition themselves. Not only does the child feel miserable due to the disease process itself; he or she can also suffer side effects from therapy for hives. Extensive evaluations in pursuit of the cause- the pokes and the prods, the time spent in the office-add to the misery, as do worried parents who fear that there is something terribly wrong with their child”. This was the introductory paragraph to an article I wrote on hives for the journal Contemporary Pediatrics.

 

Hives are those raised, red, itchy welts on the skin that come and go in crops and make the child, the parent, the primary caretaker, and the allergist go crazy.

 Not the ones I am talking about.

The Hives

These are hives, but not what I am referring to. The picture below has been taken from a health oriented web site —— is the type of hive I am referring to.

Photo by Paul Cutler

Photo by Paul Cutler 

When I was asked to write the article a few years ago, I thought it should be titled ‘Why we hate hives’. This title clearly shared the frustrations on the condition. However the editors went with ‘When the road gets bumpy: Managing chronic urticaria’. A few years prior to my review there was an article on hives in the same journal called ‘The wheal of misfortune’. Regardless of the cute phraseology, hives are a major concern.

 

I will develop and this page and share my perspective on hives using material from the article and from lectures given on the topic at an American Academy of Pediatrics (AAP), Practical Pediatrics Continuing Medical Education (CME) Course.

 

The world of hives is frustrating and confusing. This comes from personal experience. I also struggle with hives. My hives occur when grass touches my skin, when I take acetaminophen, and when the male Husky dog licks my skin but this does not happen with the female Husky. For me these are three separate, distinct, and unrelated hive responses. Lucky me.

 

My favorite hive story comes from my days at Henry Ford Hospital in Detroit, Michigan. I recall the story of a patient could take aspirin without a problem. She could eat shrimp without a problem. However, if she had shrimp and took an aspirin during the same day she would experience giant hives that lasted up to 6 months and required acute hospitalization.

 

About 20-25% of the population will experience hives. It is relatively common. For most, the problem resolves in less than a year. Unfortunately, about 40% who have hives for more than 6 months may have the condition last for many years.

Issues regarding hives-

  • They cause discomfort, disability, and distress
  • There are social, occupational (school), and domestic concerns
  • There is the need to know the cause
  • The laboratory evaluation tends to be over-enthusiastic
  • Parents are concerned as what the hives may mean and what they may portend

What is a hive (in medical lingo it is urticaria)?

  • Usually well defined, raised, itchy spots (an area of swelling on a lake of red skin)
  • The size varies from small to large to giant           
  • The shape can vary- usually circular but can be lines or splashes
  • They are almost always itchy (medical- pruritic)
  • The duration of the hives is critical- a simple allergic hive should only last a day

They can be acute or chronic (lasting hours, days, weeks as acute hives or more than 6 weeks, months, or years as chronic hives).    

What causes a hive?

            If you have paper and pencil and begin writing it may take two weeks (rough, but impressive estimate) to list all the individual causes for hives. There are many causes! The general categories of mechanisms for hives can be

         Idiopathic

  • Medical definition- of unknown causation
  • Patient’s definition- the specialist is an idiot and can’t figure it out

         Immunologic

  • Typical type one IgE mediated
  • Complement mediated (Complement is part of our immune system)

         Non-immunologic

A key point is that in many instances, perhaps up to 70%, the exact cause is not known. This leads to one of the frustrations regarding hives. Parents want to know the cause and the track record in finding that cause is poor.

 A short list of the more specific causes includes

  •  Drug/medications
  •  Food
  •  Food additives/preservatives
  •  Inhalants
  •  Transfusions
  •  Infections
  •       Viral
  •       Bacterial
  •       Parasitic
  • Plants
  • Industrial compounds/chemicals
  • Insects
  • Collagen vascular disease
  • Malignancy
  • Physical changes
  •        Water
  •        Cold
  •        Heat
  •        Sunlight
  •        Pressure
  •        Vibration
  • Hereditary tendencies
  • Thyroid disease

  Dermatographism

Dermatographism- derm = skin graphism- writing. A phyisical hive.

     Urticaria_cholinergic_1_030606

Cholinergic or heat-induced hives        

The evaluation of hives-

Detailed medical history is essential. I continuously harp on the need of the history to dictate the direction of the evaluation.

The medical history

  • What do they look like?                      
  • Where on the body?
  • When do they occcur
  • Duration- how long does an individual hive last? 
  • What does the skin look like after the hive has gone? 
  • Accompanying symptoms- fever, joint pain, tummy ache?
  • What makes it better?
  • What makes it worse?
  • Is there any swelling with the hives?

Remember – Murphy’s Law on skin rashes- by the time you see your doctor about a rash, the rash will be gone. Take pictures of the rash.       

Exposures

  • Work, home, school
  • Infections
  • Immunizations
  • Medications
  • Plants
  • Insects
  • Chemicals

The laboratory evaluation-

            Almost every test available in the Indiana University Laboratory Manual could have been ordered to evaluate hives. Sometimes the cause is obvious, most of the time it is not. Testing has a low rate of return for a specific cause. Acute hives will run its course and usually will not require tests. If the acute episode of hives tends to be recurrent, then an evaluation should be considered. Most of the time the use of the laboratory is to make sure and reassure that nothing else bad is going on with the child. This can often be determined by a detailed history and physical examination. There are a few screening tests for chronic hives (lasting everyday for more than 6 weeks).

 

These screening tests are-

  • Tests for physical stimuli- pressure to the skin, water, ice, heat
  • Blood tests
  •              Erythrocyte sedimentation rate (ESR- tends to be non-specific)
  •              Complete blood count with differential
  •              Liver function tests
  •              Urinalysis       

Other tests that have been suggested based on the history/physical examination-

  • Sinus radiographs
  • Chest radiograph
  • Dental examination
  • Stool for evidence of parasitic disease
  • Throat culture
  • ASO titer (streptococcal infection)
  • Hepatitis B surface antigen
  • Anti-nuclear antibody (ANA)
  • Rheumatoid factor
  • Complement studies- CH100, C3, and C4
  • Cryoglobulins
  • Raji test- used for immune complex disease
  • Thyroid studies
  • Skin biopsy- for vasculitis

Frequently used tests

   Allergy tests

  •   Skin prick tests
  •   Specific IgE- blood tests for allergy, RAST

 Many of the tests mentioned above have been used to look for occult infection and autoimmune disease. The child’s history helps sort out which tests to order.

 Allergy testing has a low rate of return on finding a specific cause especiallyin chronic hives. In some studies it may identify the cause in up 6% of patients with chronic urticaria. Allergy testing needs to be based on the history of exposures. Food allergy is a very rare cause of chronic urticaria. If a food is the reason for the hives, the patient/family usually has a strong index of suspicion for that food. I found a reference from 1965 in which it was thought that 33% of cases of chronic hives was due to food. A more contemporary reference from the 1990s now shows that food may account for only 4% of cases. Hives are not the subject of many major research grants. Due to the myriad of causes for hives it proves to be a difficult condition to study in clinical research. An interested clinician needs to look carefully and frequently for new information on the topic. Specific IgE (RAST or blood tests for allergy) provided a cause in only 9% of evaluations for chronic hives in a recent study.

 

Treating hives-

If an underlying exposure is discovered, then avoidance will work. If an underlying medical condition is discovered, treatment of the condition will help control the hives. Otherwise there are a number of therapies that have been used.

Medications used to treat hives

Antihistamines– This is the most common way to treat hives. Examples are Benadryl, Zyrtec, Allegra

Antihistamines as H2 blockers– medications used for excess gastric acid production. These agents work by altering the body’s metabolism of the classic antihistamines and can work on these special histamine receptors under the skin.

Oral steroids

Others (there is a very long list of medications that have been used for treatment)

 

When to consider a visit to a specialist?

            If the hives are accompanied by breathing difficulties, immediate vomiting, or loss of consciousness the condition may be anaphylaxis (the most serious immediately life-threatening allergic condition). An allergist should be involved. There are a few other instances in which a referral should be considered-

  • Peanut induced hives
  • Hives due to latex
  • Hives with vasculitis (dermatology and rheumatology referrals too)
  • Hives with other organ system reactions
  • Hives poorly responsive to treatment
  • Hives and swelling (called angioedema)

I would also add that we would be most happy to see anyone who is worried about hives.

When hives have gone on into the chronic stage, more than 6 weeks, the chances of finding a cause for the hives are about 20% (one of five). In these cases, the usual cause is a physical form of hives.

 

A few universal suggestions with hives-

  • The antihistamine will help with the itch; the rash may still be there.
  • Hives are not contagious. An acute infection that may have caused the hives may be contagious.
  • Topical lotions usually have no benefit in treating the hives. They cool the skin.
  • Hives will not respond to and are not an indication for allergen immunotherapy. 

An exception to this rule is the occurrence of hives with a ‘bee’ sting in someone over age 18 years. This is a risk factor for a life-threatening reaction to ‘bees’ (hymenoptera species) and allergen immunotherapy can help to prevent a life threatening reaction in the adult who has hives with the exposure.

2 Responses

  1. Kristin Hussey - January 20, 2010

    Great information on the “Road Gets Bumpy”….lol. I saw Dr. Vitalpur today with Devin (who was clear of course – took pictures but did not have them with me). I got lots of info from him…wish I took notes.
    Time will tell what will happen in the future. Any advice for me?

  2. fleickly - January 21, 2010

    Hives are frustrating and concerning. They can be a marker for many different things. Many times we never know the exact cause. Sometimes it is a combination of things. You have to be vigilent in your observations and look for consistency, trends, and cause/effect relationships to help drive any diagnostic considerations. I would revisit Dr. V with your note pad – make a list of your questions.