Characterisation of Disease Patterns of Dermatomyositis with Different Initial Manifestations

Purpose: To determine the characteristics and prognoses of dermatomyositis (DM) by comparing the difference in initial symptoms.Patients and Methods: A retrospective analysis was performed on the patients diagnosed with DM from 1 January 2019 to 1 January 2021. Based on the firstly presented symptoms, patients were divided into five groups, namely rash group, muscle weakness group, arthritis group, respiratory symptom group and atypical symptom group. Clinical and laboratory data were recorded. All patients were followed up until 31 May 2021.Results: In total 136 DM patients, rash (40%) was the most common initial symptom, followed by respiratory symptoms (22%), arthritis (20%), muscle weakness (10%) and atypical symptoms (8%). Rash group and atypical group had a higher positive rate of anti-TIF1 gamma antibodies than arthritis group and respiratory symptom group (P < 0.05). Respiratory symptom and arthritis groups had a higher positive rate of anti-Ro52 antibodies than rash and muscle weakness groups (P < 0.05). Respiratory group had a higher incidence of ILD than rash and atypical groups. The FVC and DLCO in respiratory group were significantly lower than rash group, arthritis group and atypical group (P < 0.05). The survival rate of rash group was significantly higher than muscle weakness group and arthritis group (P < 0.05). Conclusion: DM patients with different initial manifestations had different myositis antibodies and prognoses.