Patient-Reported Symptoms Reliably Signal True Disease Flares in Dermatomyositis

Rash drove more than three-quarters of dermatomyositis flares, and muscle weakness drove nearly 60%—and for the vast majority, those symptoms corresponded with objective signs of active disease, according to a retrospective cohort study published in Seminars in Arthritis and Rheumatism.¹

Why Flare Criteria Have Lagged Behind

Dermatomyositis is a chronic systemic inflammatory myopathy affecting the muscles, skin, lungs, joints, and heart, with most patients experiencing a relapsing-remitting or chronic course rather than a single disease episode. Flares have been linked to greater disability, higher health care utilization, and reduced quality of life, yet researchers have lacked a validated, data-driven definition of what constitutes a flare.

While the International Myositis Assessment and Clinical Studies Group proposed preliminary consensus criteria more than 2 decades ago, these measures were not designed for routine clinical use and have not been validated. Investigators from Johns Hopkins University School of Medicine and Rush University Medical Center sought to characterize objective flares in people with dermatomyositis and identify clinical risk factors that could eventually inform a standardized definition.

Researchers retrospectively reviewed the Johns Hopkins Myositis Cohort from 2003 to 2020, identifying 637 patients who met 2017 EULAR/ACR classification criteria for dermatomyositis or who had a classic dermatomyositis rash with confirmatory skin biopsy. The cohort was 75.4% female, with an average age at diagnosis of 48.7 years. Most patients were White (77.1%), while 12.9% were Black, 2.9% were Asian, and 7.1% identified as another race. On average, patients experienced a 1.2-year gap between symptom onset and diagnosis and were followed for 7.9 years.

Two reviewers manually examined clinical notes to identify increases in disease activity and the context in which they occurred. A flare was defined as new or worsening objective findings—on physical exam or testing—paired with an escalation in immunosuppressive therapy, excluding changes related to medication tapering, recent biologic infusions, or activity within 6 months of diagnosis.

When Skin and Muscle Symptoms Told the Real Story

Overall, 35.5% of patients (n = 226 of 637) experienced at least 1 objective flare during follow-up. Among a subset of newly diagnosed patients who were seen within 6 months of diagnosis (n = 367), 26.4% had at least 1 flare during follow-up, with an incidence rate of 5.1 flares per 100 person-years. The average time from diagnosis to first flare was 2.9 years.

Among patients who flared, dermatomyositis-attributable rash on exam was the most common finding (75.7%), followed by muscle weakness (58.4%), new or worsening pulmonary findings (19.0%), and inflammatory arthritis (12.4%). Patient-reported symptoms closely tracked these findings: 70.5% of patients with a flare reported rash and 62.1% reported weakness. Notably, symptoms that might be dismissed as nonspecific—fatigue and myalgia—were reported by roughly a quarter of patients experiencing a flare, and more than 90% of those reporting fatigue met objective flare criteria.

These findings align with a separate effort to formally capture the patient perspective on dermatomyositis. A qualitative study of 30 adults with dermatomyositis conducted to inform development of the Dermatomyositis Disease Symptom Questionnaire found that individuals living with dermatomyositis experience symptoms that negatively affect their quality of life, underscoring the need for disease-specific, patient-reported outcome instruments to capture concepts important to those living with the condition.² Taken together with the Johns Hopkins findings, this body of work suggests that systematically capturing what patients describe in their own words may be central to identifying flares earlier and more consistently.¹

In multivariable Cox proportional hazards models, Black race (HR, 1.55; 95% CI, 1.07-2.24) and shorter time to diagnosis (HR, 0.89; 95% CI, 0.81-0.99) were independently associated with increased flare risk. The presence of anti-synthetase antibodies was significant in univariate analysis but lost significance after adjustment.

Rethinking the Flare-Cancer Connection

The researchers also examined a long-held clinical assumption linking dermatomyositis flares to malignancy. Among patients who flared, only 2.2% had a cancer diagnosis within 6 months, 3.5% within 12 months, and 4.8% within 24 months. The authors wrote that the relationship between dermatomyositis flare and cancer diagnosis has not been previously studied and concluded that "in contrast to a widely held belief among clinicians, the majority of the flares do not herald a cancer diagnosis."

The authors acknowledged several limitations. The retrospective design meant symptoms were not systematically collected at each visit, and physical exam and ancillary testing were not standardized across patients. Because the cohort was drawn from a single tertiary referral center, the flare rate observed—considerably lower than the 64% to 72% reported in prior survey-based studies—may not generalize to the broader dermatomyositis population. Additionally, flare duration was not captured, an area the authors flagged for future research.

The findings suggest that patient-reported symptoms, particularly rash, weakness, fatigue, and myalgia, could serve as practical early indicators of disease activity worth investigating further by clinicians. The authors noted that incorporating these symptoms into a standardized flare definition could improve monitoring strategies and outcomes, while their cancer findings may help temper unnecessary diagnostic workups following a flare in patients without other red-flag features.

References

1. Saygin D, Wang X, Fitzgerald KC, et al. Clinical characteristics and risk factors associated with objective flares in patients with dermatomyositis. Semin Arthritis Rheum. Semin Arthritis Rheum. 2026;77:152947. doi:10.1016/j.semarthrit.2026.152947

2. Christopher-Stine L, Ciesluk A, Chinoy H, et al. The Dermatomyositis Disease Symptom Questionnaire (DM-DSQ): a measure to assess the patient experience of dermatomyositis symptoms. J Rheumatol. 2024;51(12):1198. doi:10.3899/jrheum.2023-1137