[Cutaneous lymphoma manifesting as pigmented, purpuric capillaries]

A few cases of patients with both purpuric pigmented dermatitis and cutaneous lymphoma have been reported. The aim of this study was to evaluate the prognosis of purpuric pigmented dermatitis.

This is a monocentric retrospective study at the dermatology department of the university hospital of Strasbourg. The records of all patients hospitalized for purpuric pigmented dermatitis between 1967 and 1997 have been reviewed.

Eight women and 9 men aged between 17 and 84 years were hospitalized for purpuric pigmented dermatitis during the reference period. Except for one patient, all had had a cutaneous biopsy showing the typical features of purpuric pigmented dermatitis. On the basis of clinical signs and course, one patient was thought to have contact dermatitis and three patients were thought to have a purpuric pigmented dermatitis-like drug eruption (meprobannate, pefloxacine and lorazepam or aspirin). The mean follow-up was one year. During follow-up, two patients developed cutaneous T-cell lymphoma after two and four years respectively and one patient developed Hodgkin's disease with skin and lymph node involvement. Another patient who suffered from purpuric pigmented dermatitis for four years had a monoclonal T cell population within the dermal infiltrate. Two patients died of their lymphoma.

This study shows that purpuric pigmented dermatitis can be associated to or evolve into lymphoproliferative disease. This course should be suspected when purpuric pigmented dermatitis is extensive, long-lasting (> 1 year), has a reticular arrangement and negative patch-testing. In this situation, a long-term follow-up and treatments indicated in the early patch stage of mycosis fungoides (PUVA therapy, chlormethine) seem adequate.