Systemic allergic contact dermatitis caused by methyl aminolaevulinate in a patient with keratosis-ichthyosis-deafness syndrome

International audience; Photodynamic therapy (PDT) is used for the treatment ofnon-melanoma skin cancers. A photosensitizer [amino-laevulinic acid (ALA) or methyl aminolaevulinate (MAL)]is applied to the skin and activated by light to producecytotoxic oxygen species. Keratosis–ichthyosis–deafness(KID) syndrome is a form of ichthyosis caused by muta-tions in theGJB2gene. Patients present with vascular-izing keratitis, hearing loss, and increased susceptibilityto some cancers. We report systemic allergic contact der-matitis caused by MAL in a patient with KID syndrome.