Atopic Dermatitis - Eczema
By Dr. Liliane Gendreau-Reid, MD, FRCPC Pediatrics; FRCPC Clinical Immunology & Allergy; Clinical Assistant Professor of Pediatrics UBC, Victoria, BC
What is it?
Atopic dermatitis (AD) is a chronic, relapsing, itchy and inflammatory skin disease. It is an "itch that erupts" meaning that scratching the itchy skin makes it worse. It is not infectious.
What causes it?
The cause of atopic dermatitis is unknown and most likely multifactorial.
- Heredity: AD occurs in 80% of children of parents who have or have had AD.
- Patients with AD have a mild immune system deficiency (B cell defect) favorising the increase in IgE (allergy antibody) and skin infections.
- The environment might also be a factor. The western lifestyle with more sterile environment, smaller family size, urban living, higher socioeconomic status, less severe infections in early life and early use of antibiotics switches the immune system to an "allergy" response.
- Foods might aggravate or prevent AD
- Food avoidance during pregnancy and while breast feeding is not recommended as studies are not conclusive.
- Exclusive breast feeding for at least 4 months seems to be protective (if supplementing is needed, regular milk formulas increase the risk more than extensively hydrolyzed formulas).
- Lactobacillus taken by the mother during pregnancy and lactation seems to decrease the risk of atopic dermatitis in the baby –studies so far show no help if taken by the baby.
- One study has shown that fish intake before the age of 9 months decreases the risk of atopic dermatitis
Once the AD has appeared, food diaries might help in identifying a trigger and this can be confirmed by allergy testing and /or challenge under allergist supervision (as there is a possible risk of severe reactions reintroducing a food positive on allergy test).
How early does it start?
Up to 90% of cases start by age 5 and 60% by age 1 year.
Who should treat it?
If the child sleeps through the night, the AD is considered mild. Preventive skin care (moisturizing and avoiding irritants as recommended in this article) should help enough. Most flare ups last about 7 days and are caused by viral illnesses. The family physician can advise the patient and prescribe the (steroid or calcineurin) creams needed for these occasional flare ups.
If the child (and parents) are awake most nights, the AD is moderate to severe. The child should be followed regularly by a dermatologist and should see an allergist at least once to determine if any allergic trigger can be identified.
If allergies are identified, a few visits might be needed with the allergist to identify (by challenges or diaries) if the foods positive on the test really need to be avoided (so as not to avoid foods unnecessarily) or if they can cause severe allergic reactions. Many of these children are at risk of asthma and preventive measures should be discussed (dust mite, pets, etc).
Does it ever go away for good?
Since 10-20 % of children will develop AD and 1-3% of adults keep it, it seems to improve significantly in 90 % of cases.
Dry skin is a chronic condition. You can improve it by:
- Avoid bubble baths – they irritate the skin
- When skin is acceptable, shower for 5 minutes or so to keep moisture in the skin.
- For severe flaring or very dry skin, tub bath for 20 minutes twice daily until finger tips wrinkle, using lukewarm water only.
- If bathing is painful or for night time control of itching, use wet compresses.
- Avoid wash cloths, rubbing, scrubbing or over use of soap. Use a mild soap like Dove or Allenbury.
- After bathing, dry off only partially by patting with a towel – do not rub.
- While some water is still on the skin, within 3 minutes and before leaving the bathroom:
- Apply steroid ointment/cream to red itchy areas.
- Apply moisturizer cream (not lotion) to other areas. (Lotions do not keep moisture in the skin as long.)
- Moisturizing should be repeated as often as necessary to keep skin soft throughout the day. (Use unscented creams such as Cliniderm, Doermer 211, Complex 15 or ask pharmacist to make 30% hydrophilic petrolatum in unscented cold cream).
- Avoid sheet fabric softeners in the dryer.
- Liquid anti-static products can be used if you double rinse.
- Wear white cotton on your skin, polyester and wool will make it itchier.
- If itchy, use an antihistamine such as Atarax or Reactine. Use at bedtime to prevent the itch/scratch cycle.
- If your skin is cracking, soak in water for a short time, then use Vaseline or Crisco on it. (Overnight in a cotton sock.)
- If your skin is inflamed (red) use a prescribed steroid cream/ointment until the redness is all cleared, not just better or it will recur soon.
- Mid potency cream/ointment on the body.
- Hydrocortisone on face and creases in babies.
- Rub in well.
Note: Elidel cream/ Protopic ointment (non-steroidal) can be used on very dry or mildly inflamed areas.
- Continued dry skin care will help prevent recurrences.
from Allergy & Asthma News, Issue 4 2008