Environmental risk factors in Juvenile dermatomyositis: a systematic review

Juvenile dermatomyositis (JDM) is a rare autoimmune vasculopathy of childhood. Alongside genetic predisposition, environmental exposures are thought to influence when the disease begins and how it progresses. Despite many reports, the evidence base is fragmented, with few studies able to draw firm conclusions. We conducted a systematic review according to PRISMA 2020 standards, searching six major databases and conference proceedings (2005–2025). Eligible studies investigated environmental, infectious, chemical, physical, lifestyle, or psychosocial exposures in children with JDM. Two reviewers independently screened articles, extracted data, and assessed study quality using NIH and ROBINS-E tools. Results were summarized by exposure type. One hundred forty-eight studies were included. Ultraviolet (UV) radiation was the most consistently reported factor, with recent sun exposure often preceding onset or chronic disease, particularly in defined autoantibody subgroups. Infections, especially viral and respiratory, were frequently described as triggers of onset or relapse. Air pollutants and maternal exposures during pregnancy also emerged as significant risks. Psychosocial stress, including early adversity and pandemic-related distress, was linked to flares. By contrast, structured exercise, particularly aquatic therapy, improved fitness and fatigue without worsening disease. Multiple modifiable environmental influences appear relevant in JDM. Strategies such as UV protection, minimizing pollutant exposure, and tailored exercise may benefit patients. Well-designed, prospective studies are urgently needed to clarify causal pathways and inform prevention. Registration number: CRD42024595442PROSPERO.