A Woman With Muscle Weakness and a Skin Rash

A 30-year-old White woman presented with a 7-month history of muscle weakness, pain and stiffness, mild nocturnal fever, and leg swelling. She developed an erythematous rash on the face and knuckles 2 months prior to our evaluation and had difficulty swallowing, climbing stairs, and rising from the toilet.

Past medical history included a Bell palsy and partial hysterectomy 4 years previously for uterine cancer.

Physical examination was unremarkable, except for erythema in the hands, face, elbows, and knuckles, and capillary proliferation in the periungual areas of the fingers ( Fig. 98A-1 ). There were no subcutaneous calcifications. Muscle strength was 4−/5 in neck flexors, 4/5 in deltoids, biceps, triceps, hip flexors, extensors, and abductors, and normal elsewhere. Her gait was normal but she had difficulty rising from a chair and sitting up from a supine position. Reflexes, sensory, and cerebellar examinations were normal. Her vital capacity was 2.04 L, 66% of predicted for her age and size. The examination was otherwise normal.

What is the Differential Diagnosis?

The patient had proximal muscle weakness of recent onset with an otherwise normal neurologic examination. This is consistent with an acquired myopathy. The characteristic skin rash is typical for dermatomyositis. The history of cancer raised the possibility of a paraneoplastic dermatomyositis, but in those patients, the association is usually with other cancers such as lung, ovary, and breast. ^1,2 The history of recurrent Bell palsy suggests sarcoidosis, but her rash was not typical of this disease. Another possibility was dermatomyositis associated with a connective tissue disorder such as lupus.

What Should be Done Next?

Laboratory studies revealed normal complete blood count and metabolic profile; erythrocyte sedimentation rate was 39 mm/h (normal, <30 mm/h), serum creatine kinase level was 461 IU/L (normal, 41–186 IU/L), and aspartate transaminase, 57 IU/L (normal, <29 IU/L).