Hemorrhagic subcutaneous nodules: an initial clinical sign of hemophilia A

Monoarthritis and Microhematomas in a 4-year-old Boy

Monoarthritis warrants a broad differential diagnosis including trauma, infection, malignancy, and hemarthrosis.1 Most children with hemophilia are diagnosed before age 2 years, with hemarthrosis typically occurring 1–2 years after bleeding into the soft tissues, skin, and mucosa.2