Atopic dermatitis (AD) is an immune-mediated inflammation of the skin, often with a significant genetic component. Pruritus is the primary symptom. Skin lesions range from mild erythema to severe lichenification. Atopic dermatitis is IgE-mediated (extrinsic type, 70 to 80% of cases) or non-IgE-mediated (intrinsic type, 20 to 30% of cases).

Causes

Atopic Dermatitis occurs when environmental exposures trigger immunologic, usually allergic (IgE-mediated), reactions in genetically susceptible people

Common environmental triggers include foods (eg, milk, eggs, soy, wheat, peanuts, fish), airborne allergens (eg, dust mites, molds, dander

Staphylococcus aureus colonization on skin due to deficiencies in endogenous antimicrobial peptides Atopic Dermatitis is common within families, suggesting a genetic component

 
Symptoms and Signs

Atopic Dermatitis usually appears in infancy, typically by 3 months

 

• In the acute phase, lasting 1 to 2 months, red, weeping, crusted lesions appear on the face and spread to the neck, scalp, extremities, and abdomen
• In the chronic phase, scratching and rubbing create skin lesions (typically erythematous macules and papules that lichenify with continued scratching)

 

Lesions typically appear in antecubital and popliteal fossae and on the eyelids, neck, and wrists Secondary bacterial infections and regional lymphadenitis are common

 
Diagnosis

Allergic precipitants of atopic Dermatitis can be identified with skin patch or prick test and/or measurement of allergen-specific IgE levels.

 
Prognosis

Atopic Dermatitis in children often improves by 5 yr of age, although exacerbations are common throughout adolescence and into adulthood. Girls and patients with severe disease, early age of onset, family history, and associated rhinitis or asthma are more likely to have prolonged disease

 
Supportive care

• Skin care involves moisturizing
• Bathing and hand washing should be infrequent and use lukewarm (not hot) water; soap use should be minimized on dermatitic areas because it may be drying and irritating
• Body oils or emollients such as white petrolatum, vegetable oil, or hydrophilic petrolatum (unless the patient is allergic to lanolin) applied immediately after bathing may help
• Fingernails should be cut short to minimize excoriations and secondary infections

 
Treatment

• Avoidance of precipitating factors
• Antihistamines can help relieve pruritus. Like Hydroxyzine, Diphenhydramine, Loratidine, Cetrizine
• Household antigens can be controlled by using synthetic fiber pillows and impermeable mattress covers; washing bedding with hot water; removing upholstered furniture, soft toys, carpets, and pets
• Antibiotics both topical Mupirocin and Fusidic acid

 
Corticosteroids

Corticosteroids are the mainstay of therapy.

Creams or ointments applied bid are effective for most patients with mild or moderate disease.

Emollients are applied between corticosteroid applications and can be mixed with them to decrease the corticosteroid

amount required to cover an area.

 
Light therapy

• Light therapy is helpful for extensive atopic Dermatitis
• Natural sun exposure ameliorates disease in many patients
• Alternatively, therapy with ultraviolet A (UVA) or B (UVB) may be used
• UVA therapy with psoralen (PUVA—see Psoriasis and Scaling Diseases: Light therapy) is reserved for extensive, refractory atopic Dermatitis