Erythema multiforme photoinduced by paroxetine and herpes simplex virus.

Erythema multiforme (EM) is a self-limited skin disease, characterized by the abrupt onset of symmetric red papules that may evolve into target lesions often precipitated by an infection. Photosensitive erythema multiforme (PEM) is a rare disorder characterized by the distribution of the lesions on sun-exposed areas. It has been described at the sites of sunburn, following episodes of polymorphic light eruption or herpes labialis and in association with drugs. To our knowledge, PEM photoinduced by selective serotonin reuptake inhibitors has not been reported. We describe a patient who had two consecutive episodes of PEM related to two different triggers: paroxetine and HSV infection. In the first episode, systemic photosensitivity was confirmed with the photobiological study. UVB-MED was decreased when the patient was taking paroxetine and did not change after its substitution for duloxetine. However, it became normal after the withdrawal of both drugs, suggesting a cross-reactivity reaction. The UVB photopatch test with paroxetine was positive. The second episode occurred after a herpes labialis relapse. At that time, UVB-MED was normal.