Concomitant Presentation of Adermatopathic Dermatomyositis, Statin Myopathy, Fibromyalgia Syndrome, Piriformis Muscle Myofascial Pain Syndrome, and Diabetic Neuropathy

Background: Differentiation of dermatomyositis from other myopathic conditions depends on characteristic histolopathologic findings on muscle biopsy. A 48-year-old diabetic man had a prior history of generalized myalgia and an elevated serum creatine kinase while on a statin. Within a few months after discontinuation of the statin, the myalgia symptoms improved and the creatine kinase normalized. Findings: An incisional biopsy of the gastrocnemius muscle revealed perifascicular muscle fiber damage, microvascular inflammation, pyknotic cytoplasmic inclusion bodies, and neurogenic atrophy with reinnervation consistent with diabetic neuropathy. Conclusion: We present the clinical findings from a patient with adermatopathic dermatomyositis in the setting of diabetic neuropathy, fibromyalgia syndrome, piriformis syndrome, and 3-hydroxy-3-methyl-glutaryl-coenzyme A [HMG-CoA] reductase inhibitor myopathy.