[Persistent scabietic nodules with cutaneous lymphoplasia]

Two patients with one year duration post-scabious nodules are reported. Lymphoid hyperplasia was found histologically and a malignant lymphoma was suspected. Six patients with pseudolymphomatous scabious nodules were found in the literature and of these only one had evidence of lymphoid follicle formation with germinal centres. Short lived and persistent scabious nodules are discussed and diagnosis with lymphomatous nodules, dermatofibroma and urticaria pigmentosa considered. A "Darier's sign" was elicited on rubbing the lesions which is probably related to the increased number of mast cells in the infiltrate and may explain the persistent pruritus. Histological criteria to separate cutaneous lymphoplasia from lymphoma are reviewed and other more common causes of lymphadenosis benigna cutis are considered. Cutaneous lymphoplasia in persistent scabious nodules is possibly an indirect evidence of the importance of immunological factors in scabies.