188.8.131.52 Atopic dermatitis
Grading & Level of Importance: B
Atopic eczema, endogenous eczema, neurodermatitis.
Highly prevalent in infants and children (10-20%) and adults (2-4%).
Dermatitis in patients with atopic diathesis with a chronic-recurrent course, characterized by classical findings of dry skin, pruritus and textural change.
Aetiology & Pathogenesis
- Genetically determined or acquired epidermal barrier defects (in some parts of the population mutation in profilaggrin gene and other structural epidermal proteins, alterations in the desquamation process), xerosis
- Genetically determined immune reaction pattern (excessive IgE production possible, disturbance in helper T-cell balance with Th2 favoured over Th1).
- Common triggers: environmental factors (humidity, water hardness, pollution), house dust mites, psychological stimuli.
Signs & Symptoms
Eczema appearance with erythema and vesiculation in the acute phase and erythema, scaling and lichenification in the chronic phases. Another clinical feature is prurigo. Pruritus always present; it can be devastating and interfere with sleeping and work productivity.
Dry skin (xerosis).
An atopy score (SCORAD, EASI, POEM) can be used to quantify diagnosis.
- Localisation may be age dependent
- Face and neck
- Flexures (antecubital, popliteal, flexor aspect of wrist)
- All parts of the body can be affected, even extending to erythroderma.
Intrinsic and extrinsic atopic dermatitis. Extrinsic: also defined allergic type, characterized by high total serum IgE levels and the presence of IgE to allergens; associated with asthma and/or rhino-conjunctivitis. Intrinsic: non-allergic, normal total serum IgE levels and the absence of specific IgE.
Laboratory & other workups
Total serum IgE >100 kU/l, sometimes blood eosinophilia, often multiple positive skin prick tests, consider patch testing against airborne allergens after tape stripping of stratum corneum (atopypatch test).
Acute: spongiosis, perivascular lymphohistiocytic infiltrates in upper dermis. Chronic: parakeratosis, acanthosis, perivascular lymphohistiocytic infiltrates in upper dermis.
Chronic-relapsing course. Cradle cap after 3 months of age, weeping dermatitis in childhood, dry, itchy skin in adolescents and adults.
Tendency to superinfection by bacteria (Staph. aureus: impetiginization) and viruses (eczema herpeticum/molluscum contagiosum).
Typical personal and family history, characteristic clinical picture, relevant laboratory tests, often coexisting atopic disorders (allergic rhinitis, conjunctivitis, asthma or type 1 food allergies).
Prevention & Therapy
1. General measures:
- Counselling regarding skin care, avoidance of aggravating factors. Patient handouts and educational material or links are valuable.
- Moisturising, often with emollients containing urea.
- Gentle cleansing (use of soap substitutes).
2. Mild forms:
- Topical corticosteroids, perhaps combination products also containing antimicrobial agents (short-term to avoid bacterial resistance).
- Topical immune modulators (tacrolimus, pimecrolimus, crisaborole).
3. Severe forms:
- Ciclosporin or other immunosuppressants (methotrexate, azathioprine, mycophenolate mofetil).
- Short-term systemic corticosteroids.
- Biological therapy: Dupilumab, a human monoclonal antibody directed against IL-4/IL-13 receptor-α.
- Several new treatments under development.
Further Images / DOIA
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