Abstract
The patient was a six-year-old boy with a history of musculocontractural Ehlers-Danlos syndrome (mcEDS). He presented to the emergency department after falling on the road the day before admission, which led to an increase in subcutaneous hematoma in his left lower leg and brief syncope. Initial blood tests revealed a decreased hemoglobin level of 8.1 g/dL (normal range: 14 g/dL). Contrast-enhanced CT showed a massive subcutaneous and intermuscular hematoma in the left thigh. He was diagnosed with hemorrhagic shock due to this extensive hemorrhage and was admitted to the ICU. The affected area was elevated, and hemostasis was achieved through compression. The swelling gradually improved, and he was discharged from the hospital on day 13 after admission. EDS is a systemic condition caused by genetic mutations affecting collagen and collagen-modifying enzymes. mcEDS is an extremely rare variant with a recently identified causative gene, characterized by abnormal connective tissue development and progressive fragility. Giant subcutaneous hematomas resulting from tissue fragility are serious complications of this disease, often occurring with minor trauma and sometimes leading to gradual hemorrhagic shock. Desmopressin nasal drops can be effective in preventing such hematomas. It is crucial to consider the risk of hemorrhagic shock from subcutaneous hemorrhage in patients with mcEDS, especially when repeated subcutaneous hematomas of unknown origin are observed.