Over a six-year period, a man develops tumid red nodules and papules on his back. What are these lesions and how can they be treated?
Over a six-year period, a 56-year-old man developed multiple, solitary and grouped, tumid red nodules and papules (0.5 to 2 cm in diameter) over his back (Figure 1). Individual lesions would last one to two months and then resolve without scarring. The nodules were erythematous, firm and not associated with ulceration, scaling or haemorrhage. There was no associated lymphadenopathy. Skin biopsy showed large nodular sheets of lymphocytes in the dermis associated with focal lymphoid follicle formation (Figure 2).