Severe Anemia as a Rare Complication of Traumatic Scalp Arteriovenous Fistula: A Case Report.

BACKGROUND Acquired arteriovenous fistulas (AVFs) of the scalp are uncommon, usually asymptomatic, and often of cosmetic concern. In rare cases, they can lead to severe anemia due to recurrent and chronic blood loss from fragile, malformed vessels in high-flow arterial and venous connections. This report describes the case of a 38-year-old woman with a traumatic AVF of the scalp presenting with severe chronic anemia. CASE REPORT A 38-year-old woman with a history of domestic violence was admitted to the Emergency Department (ED) with severe anemia (hemoglobin 3.7 g/dL; reference range 12-16 g/dL). She reported recurrent bleeding from a pulsatile occipito-parietal scalp mass that had developed gradually over 4 months. Computed tomography (CT) angiography revealed a scalp AVF supplied mainly by the left occipital artery (OA) and the parietal branch of the left superficial temporal artery (STA), with venous drainage into the retromandibular vein. The patient received 5 units of packed red blood cells. Definitive treatment included embolization of the OA and STA. Surgical excision of the lesion followed by autologous skin grafting were recommended, but the patient declined. CONCLUSIONS This report presents a case of an acquired traumatic AVF of the scalp and shows that patients can present with chronic anemia due to repeated bleeding from fragile vessels and direct arteriovenous connections. Early recognition and prompt ED imaging are essential. Embolization can control symptoms (if surgery is declined), but careful follow-up is needed. Scalp AVFs should be considered in cases of unexplained chronic anemia and further studies are required to optimize management.