Allergic Skin Diseases

• Main Focus: Atopic Dermatitis
• Eczema/Dermatitis is a common inflammatory skin condition that affects any age
• Different etiologies of eczema include atopic/allergic, contact dermatitis, napkin dermatitis, seborrheic dermatitis, stasis eczema, photo-exposure dermatitis, and nummular eczema
• Major pathogenesis of eczema includes reduced skin barrier function, allergens and irritant influx, abnormal immune response of the skin, abnormal response to bacterial infection, and psychological factors
• Clinical presentation of eczema includes acute (vesicles, weeping, erosions, crusting, peeling, erythema, swelling), chronic (thickened skin, discoloration, scales, lichenification), and combination of acute and chronic forms
• Secondary clinical presentation of eczema includes excoriations from scratching, fissures of dry hyperkeratotic thickened skin, and hyper-, hypo-, or depigmentation
• Secondary infections in eczema can be caused by bacteria (S. Aureus, S. Pyogenes), viruses (Herpes Simplex, Molluscum contagiosum, warts), and fungi (Candida Albicans)
• Atopic Dermatitis (AD) is a common relapsing skin disease characterized by chronic itching, recurrent acute flares, and dry skin
• Atopy predisposes individuals to IgE hyperresponsiveness to allergens and a tendency to develop eczema, hay fever, and asthma
• Environmental factors and genetic components play a role in the multifactorial nature of Atopic Dermatitis
• Eczema triggers include environmental dryness, humidity, heat, psychosocial stress, rough fiber clothes, exposure to irritants, scratching, secondary infection, and Filaggrin mutations
• Filaggrin deficiency is the strongest known genetic risk factor for AD, impairing normal keratinocytes cohesion and affecting the epithelial barrier
• Risk factors for AD include age, genetics, lifestyle, parental smoking, absence of breastfeeding, hygiene hypothesis, sensitization via food, house dust mite, and pets
• Pathophysiology of AD involves altered epidermal barrier function, immune dysregulation, inflammation, and neuroimmune interactions
• Symptoms of AD include erythema, edema, vesicles, oozing, crusting, lichenification, excoriations, papules, and nodules
• Diagnostic criteria of AD include essential features (pruritis, eczema, chronic relapsing course), important features (onset before age 2yrs, personal or family history of atopic diseases, dry skin), and associated features
• Comorbidities of AD include allergic rhinitis, asthma, food allergies, sensitization to environmental allergens, eye disease, psychiatric disorders, and anemia
• Differential diagnosis of AD includes allergic or irritant contact dermatitis, seborrheic dermatitis, psoriasis, scabies, drug eruptions, inborn errors of immunity, and cutaneous T cell lymphoma
• Treatment of AD involves general measures, topical corticosteroids, calcineurin inhibitors, PDE inhibitors, systemic immunosuppressants, phototherapy, new generation targeted therapy, antihistamines, antimicrobials, and wet wraps
• Eczema overview includes information on causes, triggers, symptoms, diagnosis, treatment, flare plan, maintenance plan, and conclusions about Atopic Dermatitis