Tender nodules on the sole of the foot

We present a case of a 31-year-old man with a 1-year history of a waxing and waning, painful, raised, erythematous rash on the sole of his right foot. Examination revealed tender, livedoid, erythematous nodules on the plantar aspect of the base of the right first metatarsal, with no other abnormalities. Routine blood tests, including a comprehensive autoimmune screen, were normal. A punch biopsy showed a perivascular inflammatory infiltrate in the mid-dermis, with neutrophils and eosinophils infiltrating the walls of small and medium-sized blood vessels, accompanied by leucocytoclasis.