What is atopic dermatitis?
Atopic dermatitis or atopic eczema is a long lasting itchy skin condition that is very common in children but may occur at any age.
These patients have atopic tendency meaning they are prone to develop allergic conditions asthma and allergic rhinitis (hay fever) in addition to atopic dermatitis. Often these conditions run within families. A family history of asthma, eczema or hay fever is particularly useful in diagnosing atopic eczema in infants and children.
The skin of atopic dermatitis patients is dry and very sensitive to various irritants and allergens. From time to time, most people have acute flares with the skin becoming extremely itchy and inflamed, causing patches with redness, swelling, vesicle formation (minute blisters), cracking, oozing, crusting, and scaling. In between flares, the skin may appear normal or suffer from chronic eczema with dry, thickened and itchy areas.
The itchiness of the skin causes the person to scratch, which in turn worsens the condition leading to more itch, and so on (itch-scratch cycle).
The sites affected depend on age and the parts exposed to environment. In infants scalp and cheek are commonly involved. When the child starts crawling outer aspects of limbs, particularly the wrists, elbows, forearms, ankles and knees are affected. As the child becomes older the pattern changes to involve the flexor surfaces of the same joints (the creases) especially elbow and knee.
It starts in infancy or childhood and generally but not always remits as the patient enters adulthood. It is impossible to predict whether atopic eczema will improve by itself or not in an individual.
It result from a combination of genetic (hereditary) and environmental factors. The skin is dry and has a ‘barrier defect’ which leads to increased penetrance of irritants and allergens. The substances which can lead to flare up of atopic dermatitis include soap, detergent, solvents, dirt, pollens, dust-mite, microbes, cosmetic and perfumes etc. Certain food substances like egg, cow milk, soy, peanuts, wool or synthetic fibers, food preservatives, food colors and fish can also cause flare ups. It is not a contagious condition but can be present in family members.
Atopic dermatitis is generally diagnosed based on the history and physical examination of the skin by a dermatologist. A skin biopsy (a small piece of skin that is sent to the lab for examination under the microscope) may have to be done. Blood tests- CBC, IgE levels, Phadiatop allergen testing to determine patient’s allergies.
Reduction of exposure to triggering factors is the key factor in reducing the number and severity of flare ups of the disease. Following are some pointers in developing skin-care routine.
- Avoid harsh soaps and using the recommended soap or shower gel.
- Apply a moisturizer immediately after bathing on damp skin regularly.
- Use cotton clothes only.
- Protect skin from triggers by using cotton socks, mittens etc.
- Treat infections quickly as these can flare up atopic eczema.
- Keep fingernails filed short.
- Maintain cool environment.
Medicines for atopic dermatitis are used to help control itching and heal the rash. Topical corticosteroids are the most common and effective treatment for atopic dermatitis. They are used only until the rash clears. Topical calcineurin inhibitors such as pimecrolimus cream or tacrolimus ointment are other commonly used topical medication with fewer side effects.
Antihistamines are used to treat atopic dermatitis itch and also help the patient to get sleep. Oral corticosteroids are used in severe cases when the rash covers large areas of the body or when complications occur.
Longstanding and severe eczema may be treated with an immunosupressive agents like Ciclosporin, Methotrexate or Azathioprine.
Antibiotics have to be given if the rash gets infected.