Atopic Dermatitis

Atopic Dermatitis is another clinical condition frequently seen in the allergy clinic here at Riley. This is a condition that is shared by both allergists and dermatologists. Each specialty had their unique approach. However as our understanding of this condition grows both specialties are learning from each other in order to create a common ground for diagnosis and management. The allergists see this as the first step on ‘allergic march’. Many children with atopic dermatitis go on to develop asthma and nasal allergy. If you were treated by allergists, you would be avoiding foods and have a very wet child (water wet okay). In the allergy camp the emphasis for topical therapy is frequent (two times per day) bathing. Those who may have been managed by dermatology may not have had an emphasis on food or any allergen avoidance.  Keeping the child out of the bath was the guidance in the past.

Here at Riley we have a new program in which allergy and dermatology have been working together for those children with difficult to treat atopic dermatitis. The Atopic Dermatitis Signature Center is held once a month. The AD center uses the talents of allergy, dermatology, and dietary services to help children who have been more difficult to control. The children are sent to us by their allergist or dermatologist (referral based center). The Riley crew that works in the signature center are Dr. Jeff Travers, chief of dermatology, Ms. Laura Dean, dietitian, and myself as chief of allergy services at Riley. I need to also mention the one individual who makes this center of excellence work, Treanna Porter.

Defining Atopic Dermatitis

I am still learning about how to define this condition. Dr. Jeff Travers, Chief of Dermatology at Indiana University School of Medicine, and I argue about the definition of atopic dermatitis. You will see this as eczema, atopic dermatitis, allergic atopic dermatitis, non-allergic dermatitis and finally atomic dermatitis. I really had on my patient schedule atomic dermatitis as the reason for the visit. This was most probably and error, but I felt obligated to see that patient as quickly as possible not knowing what to expect.

My working definition goes as follows; atopic dermatitis (AD) is a subset of the larger condition of eczema. Eczema is dry, itchy, and scaly skin. Atopy is the term used for a child who makes an IgE antibody to something. If by a skin test or by a blood test for specific IgE shows a positive response then the individual is atopic (they make a specific IgE). You can have evidence of a positive allergy test yet not have any reaction to that item. To be truly allergic, you need a history of a reaction with exposure and an allergy test for IgE (not IgG!!) to the item. For example- a person who has hives when they eat egg and has a positive IgE test for egg is allergic to egg (symptoms with exposure and a positive test), however a person with a positive test for egg but eats them without a reaction/problem is atopic (make antibody but that antibody is not clinically relevant).  So if you have no evidence of an elevation of IgE and no evidence of specific IgE by a blood test or skin test, then you are non-atopic, your skin diagnosis is eczema. If you have an elevated IgE and evidence of positive allergy tests, then your diagnosis is atopic dermatitis. I don’t understand the terms allergic or non-allergic atopic dermatitis, but I am open to learning about this distinction. I also love to argue about it.

A practice parameter appeared in the journal Annals of Allergy, Asthma, and Immunology(2004, Volume 93: pages S1-S21).  In that practice parameter AD is defined as a familial (inherited), chronic inflammatory skin disease that commonly presents early in infancy and childhood but can persist into adult life. Most with AD have a high or very high level of IgE.

Epidemiology

AD can affect 10-20% of children. It is very common. Most of those with AD will present before age 5 years.

Clinical Diagnosis

It is important to note that there is no single objective test for AD. AD is notable for dry, itchy, inflamed skin that has a typical look and distribution in those who have a history or evidence of atopy. I have found that there is one key question that helps sort out AD from other skin conditions. The answer to the question makes the parents pause as they reflect on what is happening. Is this a rash that itches or importantly an itch that becomes a rash? The following vignette helps illustrate that point.

Back in the 1930’s a clinician by the name of Engman took a child with AD who was also known to be sensitive to wheat. Half of the child’s body was wrapped and unavailable for scratching purposes. This child who had relatively clear skin was then fed wheat. Where he could scratch at his previously clear skin, he began to create the lesions seen with AD. When the wrapped skin was exposed, it was clear. The lesion here was that the itch was attended by scratching and scratching was severe enough to break the skin barrier and reveal the skin changes found with AD. So is it an itch that rashes or a rash that itches?

The infants and young children have involvement of the face, neck, and what is called the extensor (that surface opposite the flexing surface of an arm or leg) surfaces of the arms and legs. Older children have more leather-like skin and it favors the flexor surfaces- in the crease of the elbow or behind the knee.

Atopic dermatitis in an infant

Infantile presentation of atopic dermatitis.

Flaring of Atopic Dermatitis

It is important to note that the entire skin has the barrier abnormality that has been discovered in AD. Some areas tend to exhibit more changes than others. Many different things can cause a child to experience itchy skin and a subsequent flare of the condition. Unfortunately, many families think that it is only foods that are triggers and when there is a lack of control, the parents are looking for more food allergy to be discovered. Consider also that temperature, humidity, irritants, infection, foods, inhalants, contact allergens, and emotional stress can be responsible for a flare.

The Practice Parameters advise the careful use of allergy testing. The allergens should be relevant and at times a double-blinded food challenge is done to determine the relationship between the food and the symptoms. In clinical practice the double-blind challenge is somewhat problematic and hard to do. I would strongly advice against doing a specific IgE panel. These panels have more foods than are needed and each test increases the cost let alone the anxiety on behalf of the parent. One panel offers testing for extra foods including shrimp, clams, and walnuts all clearly not part of an infant’s diet. AD was the model of disease where it was established that allergy tests by blood or by skin testing was falsely positive 50% of the time.  What this means is that there is a real chance that there will be many positive tests for food items, however not all of them will be clinically relevant. Not all of them will mean anything. Not all of them will be associated with symptoms. I test to those foods commonly associated with food allergy in young children; egg, milk, wheat, soy, peanut, and fish (using codfish). This represents 90% of the foods associated with food allergy.

There is evidence that aeroallergens may be triggers for flares of AD. These aeroallergens include house dust mites, animal allergens, and pollen. If the child is sensitive to these items, avoidance will help. In 30-50% of AD patients patch testing to aeroallergens will show a positive skin response, however the clinical relevance of this is at this time unclear. Several studies have shown improvement of AD with the use of house dust mite avoidance measures for those who are sensitive to the dust mite. It is also important to note that depending upon where you live, it could take as long as three years to develop pollen sensitivity.

Irritants are often overlooked as a source of a flare factor. These items need to be considered as potential flares and should be avoided; soap, detergents, chemicals, abrasives clothing, extreme heat or cold, and extremes of humidity.

Infantile presentation of atopic dermatitis

Atopic dermatitis flare. The child has scratched enough to break the skin barrier. This will lead to bacterial infection of the skin.

Treatment

  • Avoidance- of allergens, irritants, infection (may be hard to avoid but should be treated).SOAPS- use Dove (unscented), Basis, Neutrogena, Aveeno, Lowila, Purpose, Cetaphil
  • Laundry- new clothing laundered prior to use, use liquid soap, use second rinse cycle
  • Clothing-loose fitting, no wool, go for cotton
  • Temperature/Humidity- not too hot, not too dry
  • Activities- encourage, swimming is great but rinse off that chlorine,
  • Outdoors- UV light may help, but avoid sunburn, sunscreens can be irritants,
  • Frequent bathing- twice a day with warm/tepid water
  • Topical ointments (not creams) as directed, mostly steroid preparations
  • Moisturizers- keep them slickered up!
  • Skin infections- need to be treated

The Difficult to Treat Patient

  • Make sure you are doing all the things above. Other considerations;
  • Wet dressings and occlusions
  • Allergen immunotherapy (allergy shots) – this is not an indication for allergy shots
  • Oral steroids- may be required; however the dramatic improvement may be followed by a rebound once the oral steroids are discontinued.
  • Phototherapy- natural sunlight, avoid sunburn
  • Systemic Immune Modulating Therapies- Cyclosporine, interferon gamma, mycophenolate mofetil, and azathioprine only under the guidance of an experienced physician

When Things Go Right

Three months later
Three months later

This is the same child shown above.

This little guy was found to have a relevant food allergens. Cows milk and egg were avoided. They used a sedating antihistamine at night. He was in the bath tub twice a day. The water was lukewarm. He was cleaned with a hand lathering of Dove soap. He remained in the tub to soak for 20 minutes. When his bath was over, the skin was patted dry with a cloth, it was not stimulated with excessive rubbing. A mild topical steroid ointment was placed on the involved areas of the face and neck. A stronger steroid ointment was used on other affected areas. Uninvolved skin was covered with a moisturizer. Two years later he underwent a food challenge. He has outgrown his food allergies. He did go on with the allergic march. Asthma and allergic rhinitis have developed over time. We still follow him at Riley. He is now 8 years old. He has a great family and they were dedicated to making the program work for him. A real success story.

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Looking good in the neighborhood! At age 8 years- 2009. My thanks to ‘the little guy’ and his family for allowing me to use these pictures.

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