Chapter 115: Atopic Dermatitis

KEY CONCEPTS

• Atopic dermatitis is a chronic skin disorder involving inflammation associated with intense pruritus (itching), a hallmark symptom. Management of atopic dermatitis must always include appropriate management of the associated pruritus.

• Atopic dermatitis is associated with other atopic diseases such as asthma and allergic rhinitis in the same patient or family. The three conditions are known as the atopic triad.

• The prevalence of atopic dermatitis appears to have increased two- to threefold in many developed and developing countries during the past three decades. Recent data indicate age and country or regional differences, with some countries showing no change or even a decrease. Rural areas appear to have lower prevalence rates.

• There are genetic and environmental factors in the pathogenesis and pathophysiologic manifestations of atopic dermatitis. The inheritance pattern is not straightforward. More than one gene may be involved in the disease, with the filaggrin gene (FLG) being a key player. Other genes coding for specific cytokines are also involved.

• Atopic dermatitis usually presents in infants and young children. The clinical presentation differs somewhat depending on the age of the patient.

• Disease severity can be determined by using SCORAD (Severity Scoring of Atopic Dermatitis). This composite index assesses both signs and symptoms to classify overall disease severity as mild, moderate, or severe, which is useful in determining appropriate treatment approach.

• Secondary bacterial skin infections are common in patients with atopic dermatitis and must be promptly treated.

• Management of atopic dermatitis must always include appropriate nonpharmacologic management of any controllable environmental factors, such as avoidance of identified triggers. These may include aeroallergens (eg, mold, grass, pollen), foods (eg, peanuts, eggs, tomatoes), chemicals (eg, detergents, soaps), clothing material (eg, wool, polyester), temperature (eg, excessive heat), and humidity (eg, low humidity).

• Nonpharmacologic management of atopic dermatitis entails managing the symptoms associated with pruritus and encouraging appropriate skin care habits such as proper bathing techniques and the copious use of moisturizers, which is a standard of care.

• Topical corticosteroids (TCS) are the drugs of first choice for atopic dermatitis.

• Topical calcineurin inhibitors (TCI), that is, tacrolimus and pimecrolimus, are alternate treatment options for adults and children over the age of 2 years.

• Phototherapy is a second-line treatment when TCS and TCI fail.

• Biologic agents (eg dupilumab) may be an option for severe atopic dermatitis in adults and adolescents (not currently approved in children).

• This chronic illness has substantial socioeconomic impact. The burden of disease is significant and the societal cost is magnified by undertreatment.

Preclass Engaged Learning Activity

Some of the treatment modalities for atopic dermatitis are also used in psoriasis. Review the discussion about topical corticosteroids (including the corticosteroid potency chart) in ...