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.