[Photochemotherapy for pityriasis lichenoides: 3 cases].

BACKGROUND: Pityriasis lichenoides is a rare cutaneous disorder of unknown origin that mainly affects children and young people. The disease consists of two variants: pityriasis lichenoides et varioliformis acuta, characterized by papular lesions evolving into necrosis and pityriasis lichenoides chronica characterized by scaly papules that may last from several months to several years. Various types of therapy have been proposed for pityriasis lichenoides, to our knockledge, photochemotherapy has never been used. We report the first 3 cases of pityriasis lichenoides treated by photochemotherapy.

CASE REPORTS: Three patients, 6, 15 and 18 years old, presented respectively with a 1 month, 2 years and 3 months history of numerous, papular and necrotic lesions or squally papular lesions. Clinical appearance and histopathologic examination of biopsy were consistent with pityriasis lichenoides et varioliformis acuta (patients 1 and 3) and with pityriasis lichenoides chronica (patient 2). They had received different treatments without significant effect: topical corticosteroids, antibiotic, UVB therapy and dapsone. Acitretin associated with PUVA were dramatically effective within few weeks.

DISCUSSION: Pityriasis lichenoides can be a severe scarring disease with significant social, psychological and physical consequences. In our opinion, photochemotherapy, which has never been used in pityriasis lichenoides, is effective. Therapeutic modalities have to be define.