DRUG-INDUCED PSEUDOLYMPHOMA AND HYPERSENSITIVITY SYNDROME - 2 DIFFERENT CLINICAL ENTITIES

Objective: To test the hypothesis that drug-induced pseudolymphoma and hypersensitivity syndrome are 2 distinct clinical entities. Design: R etrospective study from 1980 to 1993. Setting: Departments of dermatol ogy and medicine of 5 referral universitary hospitals. Patients: Twent y-four patients who met arbitrary criteria selected as being suggestiv e of lymphoma, with probable drug cause. Patients with other definite cutaneous drug-induced eruptions were excluded. Intervention: None. Ma in Outcome Measures: Suspect drugs; clinical, biological, and patholog ical findings; and evolution of each case and of 110 published case re ports. Results: Two groups were separated according to their mode of o nset and clinical aspect. Three patients (and 15 cases in the literatu re) had subacute papulonodular or infiltrated plaques, without viscera l involvment. Skin biopsy specimens showed a dense lymphocytic infiltr ate mimicking lymphoma. Healing was constant when the drug was stopped . The 21 remaining patients (and 95 published cases) had an acute wide spread eruption, with fever, enlarged lymph nodes, and multivisceral i nvolvement. Lymphocytosis, atypical lymphocytes, eosinophilia, hepatit is, and high levels of lactate dehydrogenase were frequent. Skin biops y findings were usually not specific (lymphocytic infiltrate and kerat inocyte necrosis) but sometimes mimicked lymphoma. Severe forms and re lapses occurred, even after the drug was stopped. The inducing drugs w ere the same in the 2 groups. Conclusions: These 2 groups correspond t o drug-induced pseudolymphoma and hypersensitivity syndrome. We think that they are 2 distinct entities with different clinical and biologic al features and outcome, even if the pathological findings are sometim es similar. Prospective studies are needed to confirm these facts, to evaluate the therapy, and to follow up patients.