Behind the splenomegaly: a parasitic twist in siblings with beta thalassemia trait

Thalassemia syndromes are characterized by varying degrees of ineffective hematopoiesis and increased hemolysis. β-thalassemia trait typically presents as mild microcytic anemia and rarely with significant clinical findings such as splenomegaly. However, coexisting conditions in patients from endemic regions can obscure or complicate the clinical picture. Schistosomiasis, a parasitic infection endemic to Sub-Saharan Africa, is a well-recognized cause of splenomegaly and eosinophilia. A pair of Congolese siblings with β-thalassemia trait presented with moderate splenomegaly and ultimately diagnosed with schistosomiasis. A 13-year-old female and a 15-year-old male, recently immigrated from a Tanzanian refugee camp, were found to have microcytic anemia, peripheral eosinophilia, and moderate splenomegaly on mandatory screening. Consultation with infectious diseases and hematology specialists led to a diagnostic evaluation that revealed positive Schistosoma species IgG antibodies. Other infectious and hematologic causes of splenomegaly were excluded. Both patients were treated with praziquantel, resulting in the resolution of eosinophilia and normalization of spleen size on physical examination within 12 months. This case underscores the importance of avoiding diagnostic anchoring and highlights the need for a thorough evaluation when findings deviate from the expected clinical course.