Anti‐MDA5 and anti‐SSA/Ro52 antibodies double‐positive dermatomyositis overlapping with rheumatoid arthritis‐associated interstitial lung disease: A case report

Dermatomyositis (DM) is a poorly prognostic autoimmune disease the pathogenesis of which is multifactorial and not clearly defined. DM may be influenced by genes, environment, and immunity. The typical manifestations of DM are Gottron rash, heliotrope rash, rash on the shoulders and buttocks, erythema around fingernails, excessive keratosis of the epidermis, mechanic's hands, and interstitial lung disease (ILD), among others. Anti‐melanoma differentiation‐associated 5 gene (MDA5) antibody has been strongly associated with DM. Furthermore, anti‐SSA/Ro52 antibody has been reportedly associated with DM. A 49‐year‐old woman presented with cough, expectoration, and dyspnea. Relevant examinations revealed elevated levels of muscle enzyme, double‐positive anti‐MDA5 and anti‐SSA/Ro52 antibodies, positive rheumatoid factor, and a high titer of anti‐citrullinated protein antibody. DM overlapping rheumatoid arthritis with ILD was confirmed. We suggest the use of glucocorticoids combined with immunosuppressant therapy, supplemented with gastric and liver protection, and recommend the use of intravenous immunoglobulins and rituximab.