Allergic Skin Disease: Atopic Dermatitis
The primary symptom of atopic dermatitis is itching. Many allergists and dermatologists refer to atopic dermatitis as “an itch which rashes, rather than a rash which itches.” The itch can be maddening and it is frequently worse in the evenings, interfering with rest. Early eczema or atopic dermatitis can be red, blistering or oozing. Later on, eczema may be scaly, dark and/or thickened. When the disease starts in infancy, it is often referred to as infantile eczema. The itchy rash of infantile eczema frequently involves the face, cheeks, neck, scalp and diaper areas. Many babies improve by the age of two or three years old. In teens and young adults, the patches of eczema typically occur on the hands and feet. Although these are the most common sites, any area such as the bends of the elbows, backs of the knees, ankles, wrists, face, neck and upper chest may also be affected. Never the less, many children have atopic dermatitis throughout childhood and extending into their adult life. The intense, almost unbearable itching can continue with patients frequently scratching the skin until it bleeds, leading to an increased opportunity for skin infections.
Atopic dermatitis is a complex skin disease in which there are multiple triggers, which may play a role in the continued progression of disease chronicity.
- - Anxiety/stress
- - Pollutants
- Cigarette smoke
- Diesel exhaust pollution
- - Climatic factors
- - Irritants
- Detergents, solvents
- Wool or other rough material
- - Allergens
- Food ingested
- Inhaled by nose and lungs
- Contact of skin
- - Infection
The triggers, which are important, vary from patient to another patient and may include allergens such as dust mite, cat allergy, dog allergy, mold and pollens. Other triggers include climatic factors such as dryness in the winter and heat, humidity and perspiration in the summer. Clearly, there are anxiety factors and stressors which aggravate the disease and which have the potential for rather complex inter-familial and intra-familial psychodynamics including issues of secondary gain. Additionally, irritants such as detergents, soaps, solvents, wool and perspiration may all trigger the itching with atopic dermatitis. Lastly, modern science has shown a complex and intriguing role for certain “germs” found on the skin. Staphylococcus aureus has been shown to produce certain toxins, which appear to be more effective than even allergen in triggering the allergic inflammation, which appears to drive this disease. The more we learn about the triggers which cause atopic dermatitis to flare, the more we appreciate both the complexity of the disease and realize how much more we must learn.
Between ten and thirty percent of patients with atopic dermatitis may have an allergy to a food as a contributing trigger to their disease and an allergy evaluation may be quite helpful. In infants the most likely food allergens are cow’s milk, eggs, peanut and soy. In older children, the list lengthens to include the following: cow’s milk, eggs, peanut, soy, wheat, tree nuts, fish and shellfish. In older children and adults, the list becomes attenuated to include peanut, tree nuts, fish and shellfish. Allergies to environment allergens such as animals and dust mite may also play a major role and can easily be addressed in the motivated patient.
Antihistamines may be used to help control the itching and they are best used at bedtime. This is one disease in which the older and more sedating antihistamines such as diphenhydramine (Benadryl) or hydroxyzine (Atarax) may offer advantages over the newer non-sedating antihistamines.
Topical corticosteroids have been the mainstay of topical treatment until recently when a new family of topical immunomodulating creams became available. The stronger the topical steroid the more likely it is to produce adverse local and systemic side effects. These side effects of topical steroids include skin thinning, the formation of small blood vessels and pigmentary changes and a potential to suppress the adrenal gland. Clinicians now have two new non-steroid immunomodulating creams and ointments with pimecrolimus and tacrolimus. Your allergy or skin specialist is the best qualified to outline an effective treatment program and determine whether one of these newer non-steroids creams is best for you.
The Texas Allergy, Asthma and Immunology Society (TAAIS) is a group of more than 220 board-certified Allergists/Immunologists in Texas.
An Allergist/Immunologist is a physician, usually an Internist or Pediatrician, who has had special training and experience in the field of Allergy and Immunology and who is considered to be an expert in the diagnosis and management of immune system disorders such as asthma, allergic rhinitis (hay fever), eczema, urticaria (hives), drug reactions, food allergies, immune deficiencies, and all general aspects of anaphylaxis.
A Board Certified Allergist/Immunologist is a physician who has passed the certifying examination of the American Board of Allergy and Immunology. A list of Board Certified Allergists can be found here. Those with “ABAI” under Board Certification are Board Certified Allergists/Immunologist.