Inflamed skin predisposes to sensitization to less potent allergens.

BACKGROUND: Irritant dermatitis, caused by genetic barrier dysfunction in atopic dermatitis or wet work in hand dermatitis, induces innate immune response that might predispose to allergic contact sensitization to less potent sensitizers.
OBJECTIVES: We sought to determine if positive patch test results to less potent allergens are more prevalent in patients with a history of childhood flexural dermatitis or current wet work.
METHODS: We examined our database of patients presenting to a contact dermatitis clinic tested to potential contact allergens as indicated by their history. Allergens from our most recent standard were studied if they could be classified as weak, moderate, or strong sensitizers based on published data from the local lymph node assay. Patients were stratified by a history of childhood-onset flexural dermatitis as a proxy for atopic dermatitis and by occupation.
RESULTS: History of childhood-onset dermatitis predisposed to contact allergy to weak sensitizers and wet work to medium-potency sensitizers. Neither predisposed to contact allergy from strong sensitizers. LIMITATIONS: Association cannot prove causation.
CONCLUSIONS: We conclude that strong sensitizers do not require wet work or atopy to cause sensitization. Barrier defects associated with childhood eczema and wet work may promote sensitization to weak antigens.