Neonatal subcutaneous fat necrosis. Red nodules of immobile skin on back of 2-day-old.

Subcutaneous fat necrosis. Multiple firm red nodules on back of 1-month-old.

Lupus panniculitis. Red purple nodules on upper arm of girl with lupus profundus.

Nodular vasculitis (erythema induratum). Ulcerated red nodules on calf of teenage girl.