# Delayed diagnosis of hemophilia A presenting as chronic joint swelling: a case report

## TL;DR

A 2-year-old boy with chronic joint swelling was diagnosed with hemophilia A after a detailed medical history revealed subtle bleeding signs.

## Contribution

The case highlights the importance of considering hemophilia A in children with unexplained joint swelling and the value of thorough history-taking.

## Key findings

- Chronic joint swelling in a boy was initially misdiagnosed as juvenile idiopathic arthritis.
- Detailed history revealed prolonged bruise resolution, leading to a hemophilia A diagnosis.
- Factor VIII replacement therapy successfully treated the patient.

## Abstract

Chronic joint swelling in children usually requires differential diagnosis for juvenile idiopathic arthritis (JIA). Hemophilic arthropathy, despite its rarity, may be an important differential entity, and its identification is challenging in the absence of significant bleeding history.

A 2-year-old boy admitted to our hospital with a two-month history of recurrent left knee swelling. The patient was initially diagnosed with JIA based on the MRI findings of synovitis and joint effusion. No personal or family history of bleeding disorders was noted. The vital diagnostic clue emerged from meticulous history-taking, which revealed prolonged resolution of cutaneous bruising after minor trauma. Coagulation studies showed an isolated prolonged activated partial thromboplastin time of 65.2 s with a positive correction test. Factor VIII activity was severely reduced to 2.8%, which confirmed the diagnosis of moderate hemophilia A. Factor VIII replacement therapy achieved favorable clinical outcomes in this patient.

This case emphasizes that pediatric hemophilia may mimic arthritis and underscores the essential role of thorough history-taking in identifying subtle bleeding tendencies. We recommend including coagulation tests in children with unexplained persistent joint swelling, especially in boys, before initiating treatment for JIA. This strategy helps reduce the risk of misdiagnosis and prevents harmful interventions.