A 64-year-old female presented for evaluation of a rash on her lower back of several months’ duration that was asymptomatic. She has had long-standing low back pain.
This patient was using a “field corn pad” to relieve her lower back pain. The heat from the pad produced the livedo or vascular pattern seen here. The injury is believed to be infrared injury to the reticular arteriole network in the skin.
Differential Diagnosis: Cutis marmorata has a reticular pattern but is present from birth. Erythema annulare centrifugum is typically scaly. Granuloma annulare usually has discrete annulare lesions and is not as dusky as seen here. Livedo reticularis is typically seen on the lower extremities so finding it confined just to the lower back would not be expected.