A 3-year causative study of pompholyx in 120 patients.

OBJECTIVE To assess the relative frequency of the different causes of pompholyx evoked in the literature. DESIGN Prospective survey. SETTING Clinical outpatient setting. PATIENTS A total of 120 consecutive patients with pompholyx referred to our department from 2000 through 2003. MAIN OUTCOME MEASURES Systematic investigation of different causes of pompholyx: fungal intertrigo, hyperhidrosis, atopy, contact eczema, and internal reactions with systematic provocation tests to metals, balsam of Peru, and food allergen when suspected. RESULTS The present study found the following causes of pompholyx in the 120 patients: mycosis (10.0%); allergic contact pompholyx (67.5%), with cosmetic and hygiene products as the main factor (31.7%), followed by metals (16.7%); and internal reactivation from drug, food, or haptenic (nickel) origin (6.7%). The remaining 15.0% of patients were classified as idiopathic patients, but all were atopic. (Percentages do not total 100 because of rounding.) CONCLUSIONS Our data confirm the existence of reactional pompholyx to interdigital-plantar intertrigos and endogenous reactions to metals or other allergens, but they mainly point at the unexpected importance of a so-called contact pompholyx in which cosmetic and hygiene products play a preponderant role compared with metals. The great frequency of atopic conditions, even if idiopathic pompholyx is not inferred as an equivalent of atopy, should lead to further causative investigations before undertaking more expensive or extensive treatments of refractory pompholyx.