A case of polymyositis associated with postpartum

Polymyositis in pregnancy is uncommon, especially rare in postpartum. We reported a case of polymyositis associated with postpartum, with literature review. The patient was 28-yearold woman, gave birth to twins prematurely in 25 weeks gestation due to hydramnion and they died after a few days. She noticed symmetrical muscular weakness in the shoulder and limb girdle at 3 to 4 days postpartum. The CPK level in serum elevated to 10, 089mU/ml, myogenic pattern was shown in EMG, then the patient admitted to our hospital. In the laboratory findings on admission, the elevated levels of CPK, myoglobin, aldolase and creatine were found in serum, and also myoglobin and creatine in urine showed the high level. The patient was diagnosed as polymyositis based on the abnormal pathological findings of muscle biopsy, EMG of limb muscle and above mentioned results. As the value of CPK in serum, however, already decreased to 3, 474mU/ml, she was observed without drugs. She recovered day by day, and she appeared to be improved after 3 weeks. Although the challenge test of the drugs administered to the patient prior to the initiation of polymyositis, was done, all of them were negative. Furthermore, signs and symptoms of preceding viral infections were not detected. So we considered the disease as polymyositis associated with postpartum, and discussed this case in the literature, compared with other cases.