This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pediatrics
[{'content': 'Commonest presentation of sickle cell anemia – \nSelect and explain. \nA. Priapism, B. Bone pain, C. Fever, D. Splenomegaly', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Clinical manifestations of sickle cell anemia\n\nThe clinical manifestations of sickle cell anemia are -\n\n1. Chronic hemolysis\n\nIrreversible sickle cells have rigid, nondeformable cell membranes that lead to difficulty in negotiating the splenic sinusoids, sequestration, and rapid phagocytosis. This results in extra-vascular hemolysis.\nSome intravascular hemolysis may also occur because of increased mechanical fragility of severely damaged cells.\n\n\n2. Vasoocclnsive symptoms\nReversible sickle cells express higher than normal levels of adhesion molecules and are abnormally sticky that is responsible for occlusion of microcirculation especially of bones, lungs, spleen and penis.\nVasoocclusive symptoms are the most common manifestations of sickle cell anemia.\n\nThey commonly manifest as -\n\n\nPainful bone crisis\nHand-foot syndrome → Dactylitis of bones of hands/feet.\nAutosplenectomy →Predisposes to infection by encapsulated bacteria.\nAcute chest syndrome\nSequestration crisis → Acute painful enlargement of spleen.\nAplastic crisis → due to infection by parvovirus - B19\nCNS symptoms → Seizure, stroke\nPriapism and infarction of penis\nLeg ulcers\n\nRemember\n\nSickle cell trait (heterozygous state) is almost always asymptomatic and the only significant manifestation is the renal concentrating defect presenting with isosthenuria.', 'role': 'assistant'}]