Multiple cutaneous B-cell pseudolymphomas after allergen injections

Abstract

Cutaneous pseudolymphomas are benign lymphoid hyperplasias that clinically and histologically simulate malignant cutaneous B- or T-cell lymphomas. Cutaneous T-cell pseudolymphomas are extremely rare and, in most cases, are caused by systemic treatment with antiepileptic drugs such as phenytoin or carbamazepine. 1 Cutaneous B-cell pseudolymphomas are somewhat more frequent. The single most frequent cause of cutaneous B-cell pseudolymphomas is infection with Borrelia burgdorferi, resulting in lymphocytoma cutis. Because B. burgdorferi induced cutaneous B-cell pseudolymphomas are reactive in nature in most cases, appropriate antibiotic treatment regularly results in complete remission. In contrast, rare cases of B. burgdorferi associated malignant B-cell lymphoma have been reported. 2 Other causes of cutaneous B-cell pseudolymphomas include trauma, insect bites, tattoos, gold hypersensitivity, 3 and cowpox vaccination. Only two cases of B-cell pseudolymphomas resulting from antigen injections for allergy hyposensitization have been reported. 4,5 We describe multiple cutaneous B-cell pseudolymphomas in a 24-year-old woman at sites of antigen injections during allergy hyposensitization for pollinosis.