Axonal Polyneuropathy in a Man Treated for Pulmonary Cocci: A Case of Acute Intermittent Porphyria

BACKGROUND Acute intermittent porphyria (AIP) is a rare autosomal dominant disorder that is part of a group of acute porphyria disorders usually found in females of reproductive age. Although clinically there is low penetrance, with 90% of genetically diagnosed individuals never experiencing an acute flair, consequences of acute flairs may lead to devastating results. Debilitating paresis, seizures, respiratory failure, and even death may result from AIP. Early detection is key in preventing these devastating manifestations. CASE REPORT A 67-year-old Hispanic man with a past medical history of pulmonary Coccidioides on fluconazole presented with bilateral thigh pain for 2 days. At baseline, the patient had no limitations, but now was limited to minimal walking due to his thigh pain subsequently progressing to diffuse weakness after the administration of IV Solumedrol. Over the next few months, EMG was notable for acute-on-chronic sensorimotor axonal denervation in upper and lower extremities, without evidence of myositis. Urine porphobilinogen was 58 mmol/L, which is 29 times the upper limit of normal. Treatment was started with hemin 4 mg/kg/day for 4 days. CONCLUSIONS Over our patient's clinical course, he was affected by a severe manifestation of repeated acute porphyria attacks, which started as anterior thigh pain and progressed to diffused weakness disproportionally affecting the muscles of the upper extremities. Although the patient was in his late 60's at the initial onset of AIP, his diffuse Coccidioides infection, use of azoles, and steroids likely contributed to his first AIP attack.