Atopic dermatitis (AD) is a non-contagious, common, chronic skin disorder
of long duration. It is a condition of the eczema type of skin problems.
Atopic is another word for an allergy like asthma and hay fever – and
these conditions can also present in the affected individual. Dermatitis
means skin inflammation. So together the words atopic dermatitis mean “allergic
skin inflammation”. The main feature of atopic dermatitis is itchy
skin usually causing the affected person to scratch – which further
increases the itchiness. This leads to a vicious cycle of increased itchiness
and vigorous scratching, complicating the condition.
Atopic dermatitis can affect people of all ages though it is not so common
in adults. It is most common in children, affecting about 10% to 20% of
them. Girls are more frequently affected than boys. In 90% of cases, the
disease usually occurs before the age of five. For apparently no reason,
it often worsens into conditions called flares, followed in adult life
by complete remission. However, 60% of these children affected by atopic
dermatitis continue to suffer from this disease in a more limited form
in adulthood.
Atopic dermatitis needs special attention since significant social and
financial costs are involved. The reported rising incidence of Atopic
dermatitis is further increasing these costs. It is one of the main causes
of workplace disability in adults and it is now the fourth most expensive
disease in the U.S in terms of how much it costs the economy.
Causes
Causes of atopic dermatitis are not known, but hereditary and environmental
factors are suspected. It seems certain agents trigger the onset of the
disease. These include air-borne allergens, environmental factors, emotional
stress, hormones, certain foods, and chemical irritants.
Children can inherit a genetic susceptibility to atopic dermatitis from
parents having this disease or diseases like hay fever and asthma. A malfunctioning
immune system can also be a cause that can be further exacerbated by a
dry skin. Emotional factors were once believed, wrongly, to be a cause
of atopic dermatitis, but it is now known they only worsen the condition – emotional
stress does not actually cause atopic dermatitis.
Stages of atopic dermatitis
There are three stages; the infant, childhood and adult stage. Scratching
and a desire for it, is the main feature of all stages.
Infant stage includes infants up to 2 years age and typically appears
when they are 6 to 12 weeks old. There are rashes in many places but the
diaper area is unaffected.
Childhood stage ranges from 2 years to puberty. Due to constant scratching,
the skin becomes hard and scaly. The disease in some children goes into
remission for a long time, returning at puberty due to hormones or other
reasons.
Adult stage begins at puberty and follows a pattern similar to earlier
stages. Adults may also develop eczema of the hand and foot. Those in
occupations involving frequent hand washing and exposure to chemicals
are more affected.
Symptoms
Symptoms vary between people but the common ones are, dry, itchy skin
and rashes on the face, hands, feet, inside the elbows and behind the
knees. Itching is the most important symptom. Itching is a particular
problem during sleep when there is no control over scratching.
Diagnosis
Since symptoms are unique to every patient, the doctor has to thoroughly
examine the patient and his/her family’s medical history. This is
done partly to detect the possible triggers for the disease. To aid diagnosis,
two sets of criteria, grouped as major and minor criteria, have been developed.
These are;
Major Features
- Intense itching
- Rashes in places typical of the disease
- Chronic symptoms
- Personal or family history of atopic disorders (allergies)
Minor Features
- Early onset
- Dry skin with scales or bumps
- High immunoglobulin E levels
in the blood
- Skin creases on the palms
- Hand or foot involvement
- Lip inflammation
- Nipple eczema
- Susceptibility to skin infection
- Positive allergy skin tests
Atopic dermatitis may be initially diagnosed if there are
at least three features from both categories.
Presently, there is no single test to diagnose atopic dermatitis. There
is a skin prick test, where a needle that contains the suspected allergen
is applied to the skin to see if there is a reaction. However, the test
only rules out or identifies a response to the tested allergens and does
not positively identify atopic dermatitis.
Treatment
Treatment has two main aims; healing the skin and preventing flares.
For successful treatment, full cooperation in following the doctor’s
instructions is essential.
Systemic corticosteroids are used only in resistant cases and for short
periods of time. Side effects can include high blood pressure, damaged
skin, weakened bones and cataracts. Consequently, systemic corticosteroids
are a treatment of last resort. Most commonly topical corticosteroid creams
are used.
For many years, topical corticosteroids have been prescribed to control
inflammation. These drugs, however, can have side effects like, growth
suppression, thinning of skin and infections. Because of this doctors
hesitate to prescribe them to young children, but they are readily prescribed
for adults and milder corticosteroid creams are available for teenagers.
For children above two years, new immunomodulators, which control inflammation,
reduce immune system reactions and have few side effects, have been developed.
Tar preparations can also lessen inflammation and itching. Ultra violet
(UV) light therapy is recommended in more severe cases.
Precautions
An important part of the treatment regimen is preventive measures against
exposure to substances, which worsen the atopic dermatitis condition.
These are common irritants and allergens and include:
- Wool or synthetic fibers
- Soaps and detergents
- Some perfumes and cosmetics
- Animal dander and pollens
- Dust and sand
- Cigarette smoke
Avoiding these common irritants can help reduce the atopic dermatitis
in many affected individuals. If other specific allergens are identified
with a skin prick test then these too should be avoided.
