Cause:
Pathophys:(Nejm 2008;358:1483) IgE-mediated sensitization damage vs. epithelial cell defect opens access to antigens
Sx:
Acute characterized by weeping vesicles, chronic by pruritus and lichenification
Atopic: h/o stress, allergies, asthma
Contact: h/o contact, especially when wet; burning more than itching; appears within 24 h of contact, hyperpigmentation may occur later
Neurodermatitis: h/o stress, dependent personality, self-excoriation
Si:
Atopic: medial, infraorbital skin pleat (Morgan-Dennie fold)
Contact: linear lesions somewhere if caused by Rhus plants, non-anatomic patterns
Neurodermatitis: scratching
w atopic type, incr (30% prevalence) staph infections due to absence of antimicrobial peptides (Nejm 2002;347:1151)
r/o "ID" REACTION (autosensitization), which may follow any rash, especially chronic ones of lower extremities like stasis dermatitis
Lab:
Serol:in atopics, IgE elevated 95 IU and/or 3 pos RAST tests to common allergens (Nejm 1997;337:17,20) often
Rx:
Preventive
of disease: