Info

🌱 來自: allergy and immunology

atopic dermatitis

• Pathophysiology: Epidermal barrier dysfunction (e.g., filaggrin mutations), immune dysregulation (skewed Th2 response), and altered skin microbiota; often associated with allergic rhinitis and asthma (“atopic triad”)

• Clinical features: Most commonly presents on the face and flexural areas (e.g., popliteal and antecubital fossa)

ACUTE: Intensely pruritic erythematous papules and vesicles; may be super-infected with oozing and crusting

-   CHRONIC: Dry, scaly, excoriated papules and plaques; may see lichenification and fissuring

-   Subtypes (descriptive terms of subtypes of atopic dermatitis)

•   Xerotic (asteatotic) eczema: Erythematous lesions with “plate-like” cracked scales, typically on the lower extremities; seen in older adults; associated with dry weather and/or excessive bathing

•   Nummular (discoid) dermatitis: Coin-shaped, pruritic scaly plaques, commonly on the extremities

•   Dyshidrotic eczema: Pinpoint clear vesicles on the lateral sides of the fingers

• Treatment: Emollients (e.g., petroleum jelly, Aquaphor ointment) + topical glucocorticoids. Consider topical calcineurin inhibitors (e.g., tacrolimus) or a less potent steroid for the face, genitals, and skin folds.

• Pearl: History of atopic dermatitis as a child greatly increases the risk of dermatitis in adulthood. Atopic dermatitis increases the risk of contact dermatitis. If a patient’s atopic dermatitis worsens, consider co-existing pathologies.