During childhood and infancy, an equal incidence exists for the sexes. The patient may have a history of a febrile illness or other illness without dermatologic findings. Pertinent physical findings are limited to the skin. Lesions present as localized indurated nodules with ill-defined margins similar to erythema nodosum. Nodules are raised slightly above the skin line.
Nodules are firm or hard and cold and painful.
Thigh lesions, in particular, overlap with perniosis. Skin color changes are red or violet. CP is caused by cold injury in children and in women who are obese. The abnormality probably lies in the chemical composition of the fat tissue. Anoxia, cold, and humidity may play a role.