The patient is a 35-year-old mailman who has noted progressive weakness of his arms and legs for the past six weeks. This man was in excellent health until he noticed slight difficulty in climbing stairs. Four weeks ago, he clearly noted weakness in lifting his legs at the hip. He also noted progressive difficulty in arising from a low chair. In the past two weeks, he has also had difficulty raising his arms over his head for any duration. He notices this when combing his hair or putting on an overcoat. There is no history of injury but his thigh and arm muscles have been tender for several weeks. The patient has developed a mild cough and a 15 pound weight loss in the past six weeks. One week ago, he noted a non-pruritic diffuse rash on his trunk, face and hands. His weakness has steadily progresses in the past six weeks.

 

The patient shows signs of recent weight loss. A violaceous rash is noted over the face and hands, particularly around the knuckles and fingernail beds. Examination of cranial nerves is entirely normal. Muscle bulk appears normal through the deltoid, biceps and quadriceps are slightly tender and feel indurated or rubbery. There is no wasting and no fasciculations are seen. The patient has weakness in his shoulder girdle involving deltoid, supraspinatus, infraspinatus and biceps muscles bilaterally. There is similar weakness in iliopsoas and quadriceps bilaterally but anterior and posterior tibial muscles and hamstrings are normal. Reflexes are slightly depressed but symmetrical and preserved. The plantar response is flexor bilaterally. Sensation is intact to all modalities. The patient has difficulty rising from a low chair and when seated on the floor, he must get onto his hands and feet before he can stand up. When walking, he has an obvious pelvic lordosis and tends to "waddle".

 

Routine chest x-ray shows a large right perihilar mass. Erythrocyte sedimentation rate (ESR) is elevated (54 mm/hr). EMG (electromyogram) shows decreased duration and amplitude of muscle action potential in the deltoid and quadriceps muscles bilaterally. Interference pattern with maximal activity is full. Nerve conduction times are normal in arms and legs. Serum creatine phosphokinase (CPK) is 2,500 I.U./L (normal 20-90). A muscle biopsy of the left quadriceps shows widespread scattered degeneration with many foci of inflammatory infiltrates. A skin biopsy from the hand also shows inflammatory changes.

 

The patient underwent bronchoscopy for his lung lesion and subsequently required a thoracotomy. He was also started on Prednisone (Cortisone). After three weeks, he had less discomfort and noted slowly increasing strength in his arms and legs. Creatine phosphokinase at that time had fallen to 35 I>U. His ESR was 20 mm/hour. Three months later the patient still required Prednisone but was both subjectively and objectively improved. His rash had disappeared.