Acute Muscle Injury and Subcutaneous Edema in a Patient with Anti-nuclear Matrix Protein-2 Antibody Positive Dermatomyositis Sine Dermatitis
Abstract
This case describes anti-nuclear matrix protein-2 (NXP-2) antibody-positive dermatomyositis sine dermatitis (DMSD) with an acute onset and marked creatine kinase (CK) elevation, closely mimicking drug-induced rhabdomyolysis. The patient lacked a skin rash and initially improved with hydration, but later developed respiratory failure, leading to a diagnosis via a muscle biopsy and antibody testing. Notably, the imaging findings also resembled rhabdomyolysis, further complicating differentiation. This case highlights that when anti-NXP-2-positive myositis presents as DMSD with acute, transient CK elevation and rhabdomyolysis-like imaging, however, distinguishing between these two conditions is extremely difficult. In such atypical cases, a muscle biopsy plays a critical role and should be actively considered for the diagnosis.
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BibTeX
@article{minekawa2026acute,
title = {{Acute Muscle Injury and Subcutaneous Edema in a Patient with Anti-nuclear Matrix Protein-2 Antibody Positive Dermatomyositis Sine Dermatitis}},
author = {Emi Minekawa and Yohsuke Oto and Yoshinao Muro and Ichizo Nishino and Takeshi Fukuda and Ken Yoshida and Taro Ukichi},
journal = {Internal Medicine},
year = {2026},
month = sep,
doi = {10.2169/internalmedicine.6410-25},
url = {https://www.jstage.jst.go.jp/article/internalmedicine/65/18/65_6410-25/_article},
note = {CC BY-NC-ND},
}
RIS
TY - JOUR
TI - Acute Muscle Injury and Subcutaneous Edema in a Patient with Anti-nuclear Matrix Protein-2 Antibody Positive Dermatomyositis Sine Dermatitis
AU - Emi Minekawa
AU - Yohsuke Oto
AU - Yoshinao Muro
AU - Ichizo Nishino
AU - Takeshi Fukuda
AU - Ken Yoshida
AU - Taro Ukichi
PY - 2026
DA - 2026/09/15
JO - Internal Medicine
DO - 10.2169/internalmedicine.6410-25
UR - https://www.jstage.jst.go.jp/article/internalmedicine/65/18/65_6410-25/_article
AB - This case describes anti-nuclear matrix protein-2 (NXP-2) antibody-positive dermatomyositis sine dermatitis (DMSD) with an acute onset and marked creatine kinase (CK) elevation, closely mimicking drug-induced rhabdomyolysis. The patient lacked a skin rash and initially improved with hydration, but later developed respiratory failure, leading to a diagnosis via a muscle biopsy and antibody testing. Notably, the imaging findings also resembled rhabdomyolysis, further complicating differentiation. This case highlights that when anti-NXP-2-positive myositis presents as DMSD with acute, transient CK elevation and rhabdomyolysis-like imaging, however, distinguishing between these two conditions is extremely difficult. In such atypical cases, a muscle biopsy plays a critical role and should be actively considered for the diagnosis.
SN - 1349-7235
SN - 0918-2918
ER -