Haemorrhagic manifestations in children with influenza generally mild, self-limiting

Some paediatric influenza patients presenting to emergency departments (EDs) may have haemorrhagic manifestations, which are normally mild and self-limited, according to a study.

A total of 3,363 children with influenza were included in the analysis. Of these, 67.9 percent had influenza A virus infection and 32.0 percent influenza B virus infection. The median age increased from 3.4 years in 2024 to 4.9 years in 2025 (p<0.001).

Haemorrhagic manifestations occurred in 3.8 percent of infants presenting to the ED. The most common manifestation was petechiae or purpura (2.3 percent), followed by epistaxis (1.5 percent). The incidence was higher in 2025 than in 2024 (4.4 percent vs 2.4 percent; odds ratio, 1.87, 95 percent confidence interval, 1.19‒2.94).

About one-fifth of the patients (18.9 percent) underwent blood tests. In these tested patients, platelet counts differed modestly between those with and without haemorrhagic manifestations. Coagulations parameters and thrombocytopaenia, however, showed no significant associations with bleeding.

Most patients (95.9 percent) with haemorrhagic manifestations were managed as outpatients. Hospitalizations were rare.

Haemorrhagic manifestations “are not associated with consistent or clinically relevant laboratory abnormalities, supporting the concept of a transient and multifactorial disturbance of haemostasis during influenza infection,” said the investigators, who conducted this multicentre retrospective cohort study across nine paediatric hospitals in Spain.

Children aged 0‒16 years with laboratory-confirmed influenza who presented to EDs during January‒February 2024 and 2025 were included in the study. The investigators analysed demographic characteristics, influenza virus type, haemorrhagic manifestations, available laboratory parameters, and clinical outcomes.