Objective To identify clinical and serologic correlates of cutaneous ulcers in dermatomyositis (DM). Methods We retrospectively examined a cohort of 152 DM patients. We compared the features of patients with ulcers to those without ulcers using chi-square or Fisher’s exact tests and used univariate and multivariate logistic regression models to assess the association between ulcers and clinical features such as malignancy, interstitial lung disease (ILD), and amyopathic disease. Results Forty-three patients (28%) had cutaneous ulcers. Nearly half the patients had ulcers present in more than 1 location: 24 (56%) had ulcers over the extensor surfaces of joints, 18 (42%) at the digital pulp or periungual areas, and 25 (58%) had ulcers located elsewhere. In univariate analysis ulcers were associated with Asian race, but not with other clinical and demographic features, including malignancy or ILD. In multivariate analysis ulcers were significantly associated with anti–melanoma differentiation gene 5 (anti-MDA5) antibodies (odds ratio 10.14, 95% confidence interval 1.95–52.78, P = 0.0059) and this was greatest for ulcers located at the digital pulp. In patients with cutaneous ulcers, ILD risk was specifically increased only in patients with anti-MDA5+ antibodies. Conclusion We confirmed the strong association between anti-MDA5 antibodies and cutaneous ulcers, with the novel finding that the association of cutaneous ulcers with ILD depends upon the presence of anti-MDA5 antibodies. DM patients who display this cutaneous phenotype should undergo appropriate evaluation for ILD.

Dermatomyositis is a chronic systemic autoimmune disease characterized by inflammatory infiltrates in the skin and muscle. The wide variability in clinical and serologic presentation poses a diagnostic challenge for the internist. Appreciation of the clinical variants of dermatomyositis allows for expedient diagnosis and avoidance of diagnostic error. We illustrate these challenges with the case of a 51-year-old VietnameseAmerican man who initially presented with fever of unknown origin in the absence of overt skin and muscle manifestations. The diagnosis of dermatomyositis was not evident on several clinical encounters due to the absence of these hallmark symptoms. We review the variable clinical manifestations of a subtype of dermatomyositis associated with an autoantibody against melanoma differentiation-associated protein 5 (anti-MDA5) and suggest consideration of dermatomyositis as a diagnosis in patients presenting with systemic illness and markedly elevated ferritin, even in the absence of elevated muscle enzymes and classic autoantibodies. CASE PRESENTATIONA 51-year-old Vietnamese-American male industrial engineer was admitted to the medical ward for evaluation of fever of unknown origin (FUO). He reported 3 weeks of fever, fatigue, generalized weakness, and dyspnea. His past medical history included a remote 10-pack-year history of cigarette smoking and latent tuberculosis treated with 9 months of isoniazid treatment, completed 5 years prior. He had moved from Vietnam to the United States 30 years earlier and denied any recent travel, sick contacts, or insect bites. Physical examination revealed a fatigued man, with a temperature of 38.1°C, pulse of 108 beats/minute, respiratory rate of 28 breaths/minute, and room air oxygen saturation of 96 %. Oropharyngeal, neurologic, pulmonary, cardiac, musculoskeletal, and skin evaluation were otherwise normal.A complete blood count (CBC) revealed anemia (hemoglobin 12.3 g/dL, hematocrit 38.5 %). White blood cell counts, platelet counts, and the basic metabolic panel were normal. Erythrocyte sedimentation rate (ESR) was 97 mm/hr and C-reactive protein (CRP) was 5.7 mg/dL. Muscle enzymes, sent to evaluate his weakness in the setting of elevated inflammatory markers, showed normal creatine kinase (CK) at 44 units/liter and mildly elevated aldolase to 9.4 U/L (normal: < 7.7 U/L). Blood, urine, and sputum cultures had no growth. Chest x-ray (CXR) demonstrated low lung volumes with increased reticular markings, small bilateral pleural effusions, and bibasilar opacities. During the hospitalization, he continued to have intermittent fevers as high as 39.1°C, generalized weakness, and dyspnea. Additionally, he developed bibasilar crackles on pulmonary exam and flat, diffuse, slightly hyperpigmented patches on his arms and chest that faded over several days. Extensive workup for infectious, inflammatory, and malignant causes of fever was unrevealing, including negative viral hepatitis serologies, human immunodeficiency virus antibody, anti-nuclear antibody (ANA), and anti-...