Trichoscopic, oral, and periungual fold findings as activity and damage markers in dermatomyositis patients and their correlation with myositis antibodies

There is little clarity about the clinical manifestations of dermatomyositis (DM) in the periungual folds, scalp, and oral cavity and their association with disease activity and damage. The objective of this study was to compare the prevalence of trichoscopic, oral, and periungual changes between DM and healthy patients and assess their possible association with disease activity and damage. We conducted an observational, transversal, and analytical study between 2020 and 2021. Forty DM patients were matched by sex and age with 40 healthy individuals. On the same day, all patients had a clinical evaluation of the hands, periungual folds, scalp, and oral cavity. Photographs of these areas and peripheral venous blood tests, including myositis-associated (MAAs) and myositis-specific antibodies (MSAs), were taken. Two dermatologists blinded to their diagnosis, damage, and activity levels registered the lesions. The disease activity and damage were evaluated using the Cutaneous Dermatomyositis Disease Area and Severity Index (CDASI). The presence of mechanic’s hands, Gottron’s sign, and Gottron’s papules in hands; capillary dilation, capillary tortuosity, cuticular hemorrhage, avascular areas, and cuticular hyperkeratosis in periungual folds; thick tortuous capillaries in scalp; gingival telangiectasias in the oral cavity; and positive MSAs associated with severe cutaneous involvement in DM patients (Anti-TIF1g, Anti-MDA5, Anti-SAE1/2) were associated with a higher CDASI activity score. The presence of MSAs associated with intense muscle involvement in DM patients (Anti-Mi2a, Anti-Mi2b, Anti-NPX2, and Anti-SAE1/2) was related to a lower CDASI activity score. Gottron’s sign and Gottron’s papules in hands; capillary dilation, capillary tortuosity, cuticular hemorrhage, avascular areas, and cuticular hyperkeratosis in periungual folds; basal erythema in scalp; and gingival telangiectasias in the oral cavity were associated with a higher CDASI damage score. There are trichoscopic, oral and periungual fold findings and some myositis-specific antibodies that correlate with disease activity and damage in DM patients. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00403-023-02554-0.