case_images: PMC9637802_01
case_images: Skin findings on admission. Physical examination revealed skin manifestation of dermatomyositis. (A) Mechanic's hand, (B) V-neck sign on the chest, and (C) whiplash-like erythema on the back.
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case_images: On first visit in our hosipital, he presented eyelid edema and skin rash on both upper extremities, chest, and back ( Figures 1A-C ).
case_images: Clinical imagings. (A) Chest non-contrast CT findings. Chest non-contrast CT revealed bilateral ground-glass opacity. (B) MRI findings of bilateral lower limbs. MRI shows high signals on STIR in the bilateral vastus lateralis, suggesting muscular inflammation. MRI, magnetic resonance imaging; STIR, short T1 inversion recovery. (C-E) The slide showed (C) inflammatory cell infiltration around the myofiber bundles, (D) perivascular inflammatory cell infiltration, and (E) CD8-positive lymphocytes infiltration in atrophy of the myofibers. CT, computed tomography; HE, hematoxylin-eosin; MRI, magnetic resonance imagin; STIR, short T1 inversion recovery; CD, cluster of differentiation.
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case_images: CT scan revealed interstitial pneumonia ( Figure 2A ), and he was treated with antimicrobial agents. Concurrently, he visited our outpatient dermatology clinic for eyelid edema treatment and was transiently treated with prednisolone (PSL) at 20 mg for 14 days. Magnetic resonance imaging (MRI) presented diffuse edema and inflammatory changes in the bilateral thigh muscles ( Figure 2B ). On pathologic examination, there was moderate size variation of the myofibers, and CD8-positive lymphocytes infiltration in atrophy of the myofibers, mainly at the periphery of the fascicles ( Figures 2C-E ).
case_images: Clinical course. AST, aspartate aminotransferase; CK, creaine kinase; COVID-19, coronavirus disease 2019; CRP, C-reactive protein; CT, cycle threshold; IVIG, intravenous immunoglobulin; PCR, polymerase chain reaction; PSL, prednisolone; TAC, tacrolimus.
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case_images: The clinical course is summarized in  Figure 3 .