Epidemiology of lymphomatoid papulosis.

BACKGROUND: Lymphomatoid papulosis is a rare skin disease with malignant potential. Its epidemiology is largely unknown.
METHODS: A case-control study of lymphomatoid papulosis was done to characterize the patient population and investigate the risk factors for its development. Fifty-seven patients with biopsy-proven lymphomatoid papulosis and 67 individually matched control subjects who were recruited among relatives and acquaintances of the patients answered a standard questionnaire over the telephone.
RESULTS: Among patients with lymphomatoid papulosis, 3 had a history of Hodgkin disease, 3 had non-Hodgkin lymphoma, and 10 had mycosis fungoides; none of the control subjects reported such histories. No significant differences were observed between patients and control subjects in regard to residence or travel history or exposures to various physical, chemical, and biologic agents. A higher, although not statistically significant, percentage of patients than control subjects reported a history of radiation therapy and nonlymphoid malignant lesions. No differences were found between patients and control subjects in regard to other medical conditions or family medical history.
CONCLUSIONS: Patients with lymphomatoid papulosis have a significantly increased frequency of prior or coexisting lymphoproliferative disorders, an increased frequency of nonlymphoid malignant lesions, and exposure to radiation therapy.