Diagnosis: Erythemas
Electrical burns may show erythema and bullae from the heat of arcing current or may be non-descript with severe internal damage between the points of contact and exit of the current.. Clinical photograph sourced from Wikimedia Commons (Public domain). Attribution: National Institute for Occupational Safety and Health (NIOSH) from USA.
Erythema multiforme: target lesions with three zones on acral surfaces. Erythema nodosum: tender erythematous nodules on anterior shins. Erythema annulare centrifugum: annular plaques with trailing scale.
EM: preceding HSV infection or mycoplasma. EN: sarcoidosis, IBD, medications, infections, pregnancy. EAC: associated malignancy, infections, medications. Erythema ab igne: chronic heat exposure history.
Treat underlying cause. EM: HSV prophylaxis if recurrent. EN: NSAIDs, potassium iodide, treat underlying condition. EAC: address underlying trigger. Supportive care and symptom management.
Erythema multiforme, Erythema nodosum, Urticaria, Sweet syndrome, Vasculitis, SJS
True target lesions (three zones) of EM are distinct from urticarial plaques. Erythema nodosum is a panniculitis — biopsy should include subcutaneous fat. Always investigate for underlying etiology.
Tags: erythema, inflammatory, vascular, targetoid