Contact sensitization to sunscreens.

BACKGROUND: Para aminobenzoic acid (PABA) derivatives and cinnamate are chemical sunscreens that protect against UVB (290 to 320 nm). They may occasionally produce contact and photocontact sensitization.

OBJECTIVE: To report a sensitization to octyl-dimethyl-PABA and photosensitization to 2-ethylhexyl-p-metossicinnamate in a 31-year-old man.

METHODS: A patient with a 3-year history of a relapsing dermatitis involving the face, neck, legs, and knees is reported. The eruption had recurred every summer after sunlight exposure. Patch tests with International Contact Dermatitis Research Group (IC-DRG) standard series and the photopatch series (Hermal-Trolab, Reinbek, Germany) using Finn chambers on Scanpor (Norgesplaster A/S, Oslo, Norway) were carried out.

RESULTS: We found a positive reaction to Balsam of Peru, fragrance mix, Escalol 507, and Parsol MCX (Hermal-Trolab, Reinbek, Germany). Photopatch test revealed a positive reaction only for Parsol MCX.

CONCLUSION: The incidence of allergic contact dermatitis to sunscreens is considered low. Recently sunscreens patch test concentrations have been increased from 2% to 10%. These higher percentages will probably permit the identification of more cases of sunscreens allergy in the near future.