Rheumatologists often rely on magnetic resonance imaging (MRI) in the evaluation of suspected muscular diseases. Here, we describe a case in which unexpected findings on MRI pointed to a diagnosis rarely considered as a mimicker of rheumatologic disease.
A 19-year-old man of Middle Eastern descent was admitted to our hospital for evaluation of progressive fatigue and muscle weakness. He had been a competitive 5- and 10-kilometer runner until five months before, when he started noticing muscle weakness and wasting. He reported leg pain during and after running. He continued to run for exercise, but decreased his pace due to leg pain and shortness of breath. During this period, he also lost 20 lbs., going from a slim but muscular build to a wasted appearance. He developed cold intolerance and described color changes in his fingers and hands with cold exposure. He reported intermittent hematuria after running and dark stools suspicious for melena. He denied diarrhea. He stated his appetite was normal and that he was eating a well-rounded diet, which his mother confirmed. He had decreased libido and had noticed his testicles had become smaller. He denied any rash or patchy alopecia but noted diffuse mild hair loss. He denied oral ulcers and photosensitivity.
Prior to admission, he had been evaluated by a nephrologist, who diagnosed recurrent fluid-responsive acute kidney injury, anemia and low testosterone. His medications were oral iron supplements and diphenhydramine as needed for sleep. He had no allergies. His family history was notable for consanguinity, as his parents are distant cousins. His father had thyroid cancer, and a great aunt had multiple sclerosis. There was no family history of muscular dystrophy, myositis, systemic lupus erythematosus or scleroderma. The patient had recently relocated from the Middle East to Boston to enroll in college. He drank one glass of wine per week but denied tobacco or illicit drug use.
On physical exam, he was afebrile, with a peak temperature of 98.1ºF during the previous 24 hours. His heart rate was 49, and his blood pressure was 101/66. He was breathing at a rate of 18 breaths per minute, and he had an oxygen saturation of 100% on room air. He was slim and had a body mass index of 17. He appeared somewhat listless. He was somewhat reluctant to put away his math homework for the exam, but was cooperative overall. His sclera were clear, and no heliotrope rash or periorbital edema was present. He did not have oral or nasal ulcers, swelling or tenderness to palpation of his salivary glands, or cervical or supraclavicular lymphadenopathy. His lungs were clear to auscultation. His heart rate was bradycardic but regular, without murmurs. His abdomen was notable for well-developed abdominal muscles. There was no hepatosplenomegaly. His extremities were warm and non-edematous. He had strong radial and pedal pulses. Neurological exam revealed good comprehension and intact cranial nerves. Muscle strength was 5-/5 in the proximal lower-extremity muscles, and 5/5 for all other muscle groups. There were no sensory deficits. His gait was normal. Joint exam was unremarkable. Skin exam revealed dry skin and erythema of the interdigital webs of his hands. He also had signs of chronic excoriation of the distal fingers of his right hand.