Subacute cutaneous lupus erythematosus and life-threatening hypokalaemic tetraparesis: a rare complication.

We describe a patient with lesions of subacute cutaneous lupus erythematosus associated with high titres of anti-Ro and anti-La antibodies who developed a rapidly progressive flaccid tetraparesis due to profound hypokalaemia. After investigation she was found to have distal renal tubular acidosis (dRTA) without pathological evidence of lupus nephritis. It is likely that her dRTA was a manifestation of associated Sjögren's syndrome, which had been otherwise asymptomatic. This is the first report of such a complication in the dermatological literature.