Clinical features of dengue-associated myositis in children: a retrospective study

The presentation of dengue as infectious myositis is considered an atypical and often underrecognized manifestation. This study aimed to characterize the clinical features and outcomes of pediatric patients diagnosed with dengue-associated infectious myositis, to delineate their sociodemographic profiles at the time of diagnosis, and to evaluate their laboratory findings and clinical outcomes.

The authors conducted a retrospective observational study in the pediatric department of a tertiary care hospital in the state of Bahia, Brazil, including patients up to 14 years who were admitted with clinical features of infectious myositis and laboratory-confirmed dengue infection between January 2022 and July 2024. Sociodemographic characteristics, clinical manifestations, laboratory parameters and outcomes were analyzed.

Data from 176 patients were analyzed. A higher incidence was observed among male patients (68.8%), with most cases occurring during the winter season (56.25%). The mean age was 9.25 ± 3.22 years. Fever was the most frequent symptom (96%), followed by myalgia (89.2%). Calf pain was reported in 69.3% of cases. Regarding creatine phosphokinase (CK) levels, 46% of patients had values between 1000-5000 U/L, while 17% presented with CK > 5000 U/L at admission. None of the patients developed acute kidney injury or died.

Dengue-associated myositis exhibited a benign clinical course in this symptomatic pediatric cohort. However, these findings suggest that clinical and laboratory parameters may support a risk-based clinical approach to patient monitoring and management; prospective studies are needed to validate risk stratification strategies.