What is ACD?

Common etiological allergens are nickel, balsam of Peru, chromium, neomycin, formaldehyde, fragrance, poison Ivy. Sensitization lasts 10-15 days in man, first step has no clinical consequence but may induce primary ACD (hapten-specific skin inflammation 5-15 days after contact). It results from inflammation caused by type IV HS cellular immune response. Acute lesions (papules/vesicles/weeping/crusting/erythema/edema/ pruritis) Prior sensitization is essential here, and needs re-exposure to occur after 6-12 hours. Chronic lesions fissuring, skin thickening, lichenification, acneiform eruption, hypo/er pigmentation. For children occurs by age 6 months