USMLE Step 2 Quiz
Practice Anemias And Cytopenias in USMLE Step 2 with focused quiz questions that help you check what you know, review explanations, and build confidence with test-style prompts.
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A 68-year-old man with a long history of poorly controlled rheumatoid arthritis presents with fatigue. He is not taking any medications known to cause bone marrow suppression. Laboratory studies show: Hemoglobin 9.8 g/dL, MCV 85 fL, Serum iron 35 µg/dL (low), Total iron-binding capacity (TIBC) 200 µg/dL (low), Ferritin 450 ng/mL (high).
The pathogenesis of this patient's anemia is primarily driven by the systemic elevation of which of the following substances?
This quiz focuses on Anemias And Cytopenias, giving you a quick way to practice the rules, question types, and explanations that matter most for USMLE Step 2.
Try each quiz question before looking at the correct answer. Use the explanations to review missed ideas, then come back to similar questions until the pattern feels familiar.
A 68-year-old man with a long history of poorly controlled rheumatoid arthritis presents with fatigue. He is not taking any medications known to cause bone marrow suppression. Laboratory studies show: Hemoglobin 9.8 g/dL, MCV 85 fL, Serum iron 35 µg/dL (low), Total iron-binding capacity (TIBC) 200 µg/dL (low), Ferritin 450 ng/mL (high).
The pathogenesis of this patient's anemia is primarily driven by the systemic elevation of which of the following substances?
Explanation: This patient has anemia of chronic disease (ACD), also known as anemia of inflammation, secondary to his rheumatoid arthritis. The laboratory pattern of low serum iron, low TIBC, and high ferritin is characteristic of ACD. The central pathophysiologic mechanism involves inflammatory cytokines (like IL-6) stimulating the liver to produce hepcidin. Hepcidin is a peptide hormone that downregulates ferroportin, the iron transport channel on enterocytes and macrophages. This leads to decreased intestinal iron absorption and increased iron sequestration within macrophages, resulting in a functional iron deficiency despite adequate body stores (high ferritin).
A 28-year-old woman presents to her primary care physician with a 3-month history of progressive fatigue, shortness of breath on exertion, and a craving for ice chips. She reports heavy menstrual periods lasting 7-8 days. Physical examination reveals pale conjunctiva and koilonychia. Laboratory studies show: Hemoglobin 8.9 g/dL, Hematocrit 27%, MCV 72 fL, Platelet count 450,000/µL, WBC count 7,500/µL. The peripheral smear shows microcytic, hypochromic red blood cells.
Which of the following is the most appropriate initial treatment for this patient's condition?
Explanation: This patient presents with classic signs and symptoms of iron deficiency anemia (fatigue, exertional dyspnea, pica, koilonychia) secondary to menorrhagia, confirmed by microcytic anemia on lab testing. The most appropriate initial treatment for uncomplicated iron deficiency anemia in a hemodynamically stable patient is oral iron replacement, such as ferrous sulfate. Blood transfusion is reserved for hemodynamically unstable patients or those with severe symptoms (e.g., angina). IV iron is typically used for patients who cannot tolerate or absorb oral iron, or have ongoing blood loss that outpaces oral replacement. Erythropoietin is used for anemia of chronic kidney disease or chemotherapy-induced anemia.
A 45-year-old woman with a history of Crohn disease involving the ileum presents with fatigue. Her laboratory studies show a hemoglobin of 10.2 g/dL and an MCV of 108 fL. Serum vitamin B12 level is low, and serum methylmalonic acid (MMA) and homocysteine levels are both elevated.
Which of the following is the most appropriate long-term management for this patient's anemia?
Explanation: This patient has macrocytic anemia due to vitamin B12 deficiency, confirmed by a low serum B12 level and elevated levels of both MMA and homocysteine. Her Crohn disease involving the terminal ileum is the cause, as this is the primary site of vitamin B12 absorption. Because her deficiency is due to malabsorption, oral supplementation is unlikely to be effective. Therefore, the most appropriate long-term management is parenteral (intramuscular or subcutaneous) vitamin B12 supplementation to bypass the gut.
An 22-year-old African American man is treated with dapsone for dermatitis herpetiformis. Three days later, he develops fatigue, back pain, and dark urine. His hemoglobin level has dropped from 14.5 g/dL to 9.0 g/dL. The peripheral blood smear reveals red blood cells with peripherally displaced hemoglobin ('bite cells') and Heinz bodies with a crystal violet stain.
This patient's acute hemolytic episode is most likely due to an inherited deficiency of which enzyme?
Explanation: This is a classic presentation of acute hemolysis secondary to G6PD deficiency, an X-linked recessive disorder common in individuals of African, Mediterranean, and Asian descent. The deficiency impairs the ability of red blood cells to handle oxidative stress. Drugs like dapsone, sulfonamides, and antimalarials can precipitate hemolysis. The oxidative stress leads to the formation of Heinz bodies (denatured hemoglobin), which are removed by splenic macrophages, creating 'bite cells.' Pyruvate kinase deficiency is a rare cause of chronic hemolytic anemia. Spectrin deficiency causes hereditary spherocytosis. Catalase is an antioxidant enzyme, but its deficiency is not associated with this clinical picture.
A 25-year-old man presents with a 3-month history of progressive fatigue, recurrent sinusitis, and gingival bleeding when brushing his teeth. He denies any medication use or toxic exposures. Complete blood count shows: Hemoglobin 7.1 g/dL, Hematocrit 22%, Platelet count 25,000/µL, WBC count 1,800/µL with an absolute neutrophil count of 300/µL. The reticulocyte count is 0.2%. A peripheral smear is remarkable only for a paucity of all cell lines.
Which of the following investigations is required to establish a definitive diagnosis?
Explanation: The patient's presentation with pancytopenia (anemia, thrombocytopenia, and neutropenia) and a low reticulocyte count (indicating a hypoproliferative state) is highly suspicious for aplastic anemia. While other conditions can cause pancytopenia, the most definitive diagnostic test to confirm aplastic anemia is a bone marrow aspiration and biopsy. This will show a markedly hypocellular or 'empty' marrow, with fat replacing hematopoietic cells. Vitamin levels should be checked, but they are unlikely to explain the full picture. Flow cytometry is used for PNH or leukemia. An ultrasound might show splenomegaly but is not diagnostic for the primary marrow failure.
A 19-year-old woman presents with intermittent jaundice, particularly during a recent viral illness. She has a family history of anemia and cholecystectomy at a young age in her mother. Physical examination reveals mild scleral icterus and a palpable spleen tip. Labs show: Hemoglobin 10.8 g/dL, MCV 82 fL, MCHC 37.5 g/dL (high), Reticulocyte count 8%. The direct Coombs test is negative.
Which of the following is the most likely diagnosis?
Explanation: This patient's presentation of chronic, mild hemolytic anemia with intermittent jaundice (worsened by stressors like illness), splenomegaly, and a positive family history is classic for hereditary spherocytosis (HS). Key laboratory findings are the elevated MCHC (due to cellular dehydration and the spherical shape of RBCs) and a negative Coombs test, which rules out autoimmune hemolysis. The diagnosis can be confirmed with an osmotic fragility test or eosin-5-maleimide (EMA) binding test. G6PD deficiency presents with episodic, not chronic, hemolysis. Sickle cell trait is typically asymptomatic.
A 58-year-old man with a history of seizures well-controlled on phenytoin presents with a new-onset petechial rash on his legs and oral mucosal bleeding. He has not started any other new medications. Laboratory testing reveals an isolated platelet count of 15,000/µL. Hemoglobin and WBC count are normal. The peripheral smear shows a few large platelets but is otherwise unremarkable.
Which of the following is the most appropriate initial step in management?
Explanation: The patient presents with severe, isolated thrombocytopenia. While immune thrombocytopenia (ITP) is a consideration, a significant number of cases of isolated thrombocytopenia are drug-induced. Phenytoin is a well-known cause of drug-induced immune thrombocytopenia. The first and most critical step in management is to stop the offending agent. If the platelet count recovers after discontinuation, the diagnosis is confirmed. Corticosteroids are used for ITP, but ruling out a drug cause is paramount. Platelet transfusion is only indicated for life-threatening bleeding. A bone marrow biopsy may be considered if the platelet count does not recover or if other cytopenias develop.
A 34-year-old woman with systemic lupus erythematosus presents with acute onset of severe fatigue, jaundice, and dark urine. Her hemoglobin is 6.5 g/dL, MCV is 98 fL, reticulocyte count is 12%, total bilirubin is 4.5 mg/dL (indirect 3.8 mg/dL), and lactate dehydrogenase (LDH) is 800 U/L. The peripheral smear shows numerous spherocytes.
Which of the following is the most appropriate next step to confirm the diagnosis?
Explanation: The patient's presentation with acute anemia, signs of hemolysis (jaundice, dark urine, high indirect bilirubin, high LDH, high reticulocytes), and spherocytes on smear, in the context of SLE, is highly suggestive of warm autoimmune hemolytic anemia (AIHA). The definitive diagnostic test for AIHA is the direct antiglobulin (Coombs) test, which detects IgG antibodies and/or complement C3 bound to the surface of the patient's red blood cells. The osmotic fragility test is used for hereditary spherocytosis. Hemoglobin electrophoresis is for hemoglobinopathies. A bone marrow biopsy is not indicated as a first step.
A 75-year-old man presents for evaluation of fatigue. His CBC is notable for a hemoglobin of 9.2 g/dL, MCV of 106 fL, WBC count of 3,200/µL, and platelet count of 85,000/µL. Review of the peripheral smear reveals macro-ovalocytes and neutrophils with bilobed nuclei (pseudo-Pelger-Huët anomaly). His vitamin B12 and folate levels are normal.
What is the most likely underlying diagnosis?
Explanation: This patient's presentation of macrocytic anemia with other cytopenias (leukopenia, thrombocytopenia) in an older adult, along with dysplastic features on the peripheral smear (pseudo-Pelger-Huët anomaly), is highly characteristic of myelodysplastic syndrome (MDS). MDS is a group of clonal hematopoietic stem cell disorders characterized by ineffective hematopoiesis, leading to cytopenias and a risk of transformation to acute myeloid leukemia (AML). While AML would present with blasts, MDS is defined by dysplasia. Aplastic anemia presents with pancytopenia but typically lacks dysplastic features. CLL involves lymphocytosis, not pancytopenia.
A 72-year-old woman with a history of a partial gastrectomy 10 years ago presents with a 6-month history of progressive gait instability and numbness and tingling in her feet. Her family notes recent memory difficulties. On examination, she has decreased vibration and position sense in the lower extremities. Laboratory results show: Hemoglobin 9.5 g/dL, Hematocrit 28%, MCV 115 fL, Platelet count 130,000/µL, WBC count 3,800/µL. A peripheral smear shows macro-ovalocytes and hypersegmented neutrophils.
What is the most likely diagnosis?
Explanation: This patient's presentation of macrocytic anemia (MCV 115) with characteristic peripheral smear findings (hypersegmented neutrophils) and prominent neurologic symptoms (paresthesias, gait instability, memory changes) is classic for vitamin B12 (cobalamin) deficiency. Her history of partial gastrectomy is a significant risk factor, as it can lead to the loss of intrinsic factor-producing parietal cells, causing malabsorption of B12. Folate deficiency causes a similar megaloblastic anemia but does not cause the neurologic deficits seen here. Myelodysplastic syndrome can cause macrocytic anemia but is less likely to present with these specific neurologic findings. Anemia of chronic disease is typically normocytic or mildly microcytic.
A 25-year-old asymptomatic man of Mediterranean descent undergoes routine pre-employment laboratory testing. His complete blood count reveals: Hemoglobin 11.5 g/dL, Hematocrit 35%, MCV 68 fL, Red blood cell count 5.9 million/µL. Further studies show a serum iron of 90 µg/dL (normal 60-170), TIBC of 300 µg/dL (normal 250-450), and ferritin of 150 ng/mL (normal 30-400). Hemoglobin electrophoresis is performed.
Which of the following findings on hemoglobin electrophoresis is most consistent with the suspected diagnosis?
Explanation: The patient's clinical picture of asymptomatic, marked microcytosis (MCV 68) with a normal RDW (implied by high RBC count for the degree of anemia) and normal iron studies is classic for beta thalassemia minor (trait). The definitive diagnosis is made by hemoglobin electrophoresis, which characteristically shows an elevated level of Hemoglobin A2 (>3.5%). Increased Hemoglobin F is more prominent in beta thalassemia major. Hemoglobin S is characteristic of sickle cell disease. Alpha thalassemia trait would typically have normal hemoglobin electrophoresis results.
A 50-year-old man presents with a 2-month history of fatigue and easy bruising. He has no significant past medical history and takes no medications. A complete blood count reveals a hemoglobin of 7.9 g/dL, a platelet count of 22,000/μL, and a white blood cell count of 2,100/μL with an absolute neutrophil count of 500/μL. The peripheral smear shows normocytic, normochromic red cells, and no blasts are seen.
Which of the following is the most appropriate next step to determine the etiology of this patient's condition?
Explanation: The patient has pancytopenia, which is a decrease in all three major blood cell lines. The differential diagnosis is broad and includes primary marrow failure (e.g., aplastic anemia, myelodysplastic syndrome), marrow infiltration (e.g., leukemia, lymphoma, metastatic cancer), peripheral destruction (e.g., hypersplenism), and severe nutritional deficiencies. Since the peripheral smear is non-diagnostic (no blasts), the most critical next step is to directly examine the bone marrow. A bone marrow aspiration and biopsy can differentiate between these possibilities by assessing cellularity, morphology, and clonality, thus establishing a definitive diagnosis and guiding further management.
A 42-year-old woman with long-standing rheumatoid arthritis presents with progressive fatigue. Laboratory studies show Hb 9.2 g/dL, MCV 78 fL, serum iron 35 µg/dL (60-170), transferrin saturation 10% (20-50), total iron-binding capacity 180 µg/dL (250-400), and ferritin 380 ng/mL (15-150). What is the most appropriate next step in management?
Explanation: When you encounter anemia in patients with chronic inflammatory conditions like rheumatoid arthritis, you need to distinguish between iron deficiency anemia and anemia of chronic disease (ACD). This patient's lab pattern is classic for ACD: low serum iron, low transferrin saturation, but crucially, low total iron-binding capacity (TIBC) and elevated ferritin. In true iron deficiency, you'd expect high TIBC (>400 µg/dL) as the body tries to capture more iron, and low ferritin (<15 ng/mL). Here, the elevated ferritin (380 ng/mL) indicates adequate iron stores, but the iron is sequestered and unavailable due to chronic inflammation. The inflammatory cytokines, particularly IL-6, increase hepcidin production, which blocks iron release from macrophages and decreases iron absorption. Choice C is correct because treating the underlying inflammation is the primary intervention for ACD. Better disease control will reduce inflammatory cytokines, decrease hepcidin, and allow stored iron to become available for erythropoiesis. Choice A is wrong because IV iron won't help when iron stores are already adequate but sequestered. Choice B fails for the same reason - oral iron supplementation is ineffective in ACD and may even worsen inflammation. Choice D (bone marrow biopsy) would be appropriate if you suspected sideroblastic anemia, but the clinical picture doesn't support this. Study tip: Remember the ferritin level as your key differentiator - low in iron deficiency, high in anemia of chronic disease. When ferritin is elevated in chronic inflammatory conditions, treat the inflammation, not the iron.
A 25-year-old African American man develops dark urine and jaundice two days after receiving trimethoprim-sulfamethoxazole for prostatitis. Vitals are stable. Labs: Hb 7.8 g/dL (baseline 14), MCV 90 fL, reticulocytes 15%, LDH 680 U/L (100-220), haptoglobin undetectable, total bilirubin 5 mg/dL (mostly indirect). Peripheral smear reveals bite cells. Which additional test is most likely to confirm the underlying diagnosis once the episode resolves?
Explanation: This question tests your ability to recognize drug-induced hemolytic anemia and understand the timing of diagnostic testing for enzyme deficiencies. The clinical picture screams hemolytic anemia: dramatic hemoglobin drop, elevated reticulocytes and LDH, undetectable haptoglobin, and indirect hyperbilirubinemia. The key clues are the African American ethnicity, trimethoprim-sulfamethoxazole trigger, and bite cells on smear. Bite cells are pathognomonic for oxidative hemolysis, which occurs when red cells can't handle oxidative stress due to glucose-6-phosphate dehydrogenase (G6PD) deficiency. G6PD deficiency is X-linked and common in African Americans. During hemolytic episodes, G6PD-deficient cells are preferentially destroyed, leaving behind younger cells with higher enzyme levels, which can falsely normalize G6PD levels. Therefore, you must wait until after recovery to get an accurate measurement, making choice D correct. Choice A is wrong because pyruvate kinase deficiency causes chronic hemolysis, not episodic oxidative crises triggered by specific drugs. Choice B tests for hereditary spherocytosis, which presents with spherocytes, not bite cells, and isn't typically drug-induced. Choice C evaluates for paroxysmal nocturnal hemoglobinuria (PNH), but PNH doesn't cause bite cells and isn't associated with sulfa drugs. Remember this key principle: When you suspect G6PD deficiency during an acute hemolytic episode, always retest enzyme levels after the crisis resolves. Testing during acute hemolysis often gives falsely normal results due to selective destruction of deficient cells.
A 67-year-old man treated with chronic omeprazole therapy for gastroesophageal reflux disease presents with paresthesias of both feet and macrocytic anemia. Labs: Hb 10.6 g/dL, MCV 114 fL, leukocytes 4,500/µL, platelets 110,000/µL. Peripheral smear shows hypersegmented neutrophils. Serum methylmalonic acid and homocysteine are both elevated. Which pathophysiologic mechanism most likely explains his cytopenias?
Explanation: When you encounter a patient with macrocytic anemia, paresthesias, and elevated methylmalonic acid plus homocysteine, you're dealing with vitamin B12 deficiency. The key insight here is recognizing how chronic proton pump inhibitor (PPI) use can lead to this deficiency through an autoimmune mechanism. Chronic PPI therapy reduces gastric acid production, which over time can trigger autoimmune gastritis. This autoimmune process targets gastric parietal cells, the same cells that produce intrinsic factor essential for B12 absorption in the terminal ileum. Without intrinsic factor, B12 deficiency develops, leading to megaloblastic anemia (high MCV, hypersegmented neutrophils) and neurologic symptoms (paresthesias). The elevated methylmalonic acid and homocysteine confirm B12 deficiency specifically, as these metabolites accumulate when B12-dependent enzymatic reactions are impaired. Answer A correctly identifies this autoimmune destruction of parietal cells. Answer B is incorrect because folate deficiency would elevate homocysteine but not methylmalonic acid, and folate absorption occurs in the jejunum, which isn't directly affected by PPI-induced gastritis. Answer C mentions copper deficiency, which can cause cytopenias but wouldn't produce the specific lab pattern of elevated methylmalonic acid and homocysteine. Answer D suggests direct myelotoxicity from PPIs, but this doesn't explain the specific B12 deficiency markers or the neurologic symptoms. Remember: elevated methylmalonic acid + homocysteine = B12 deficiency. In patients on chronic PPIs, think autoimmune gastritis leading to loss of intrinsic factor production.
A 31-year-old woman who follows a strict vegan diet presents with fatigue and glossitis. She recently began self-medicating with large doses of folic acid after reading about anemia online. Laboratory data: Hb 7.9 g/dL, MCV 103 fL, leukocytes 3,800/µL, platelets 92,000/µL. Peripheral smear shows oval macrocytes, anisopoikilocytosis, and hypersegmented neutrophils. Serum folate is high, and vitamin B12 level is very low. What is the most likely explanation for the persistent cytopenias despite folate supplementation?
Explanation: When you encounter a case of megaloblastic anemia with neurological symptoms in a vegan patient, think about the intricate relationship between folate and vitamin B12 metabolism. Both vitamins are essential for DNA synthesis, but B12 has unique additional roles that folate cannot replace. The correct answer is A. In B12 deficiency, methylmalonyl-CoA accumulates because B12 is required as a cofactor for methylmalonyl-CoA mutase. This accumulation leads to incorporation of abnormal fatty acids into cell membranes, particularly affecting myelin synthesis in the nervous system and causing ineffective hematopoiesis in the bone marrow. While folate can temporarily help with DNA synthesis (explaining why some patients initially improve), it cannot address the methylmalonyl-CoA pathway dysfunction, leading to persistent cytopenias and potential neurological damage. Option B incorrectly suggests this is iron deficiency, but the high MCV and macrocytic picture clearly indicate megaloblastic anemia, not iron deficiency (which causes microcytosis). Option C presents a common misconception - folate doesn't compete with B12 for absorption since they use different transport mechanisms. Option D misinterprets the pathophysiology; this isn't aplastic anemia but rather ineffective hematopoiesis due to B12-specific metabolic dysfunction. Remember this key principle: folate can mask the hematological signs of B12 deficiency but cannot prevent the neurological complications or completely correct the ineffective hematopoiesis. Always check B12 levels in megaloblastic anemia, especially in vegans, and never give folate alone without ruling out B12 deficiency first.
A 53-year-old man presents with exertional dyspnea. Complete blood count: Hb 6.8 g/dL, MCV 66 fL, leukocytes 7,000/µL, platelets 280,000/µL. Iron studies: serum iron 210 µg/dL (60-170), transferrin saturation 85%, ferritin 1,100 ng/mL. Hemoglobin electrophoresis: HbA2 6.2% (normal 1.5-3.5), HbF 3%. Which of the following is the most appropriate long-term management to prevent disease complications?
Explanation: When you encounter microcytic anemia with elevated iron studies and increased HbA2, you're dealing with beta-thalassemia. This patient's presentation—microcytic anemia (MCV 66 fL), elevated HbA2 (6.2%), and iron overload (high serum iron, transferrin saturation 85%, ferritin 1,100)—points to beta-thalassemia intermedia or major. The correct answer is C because beta-thalassemia patients develop iron overload through two mechanisms: ineffective erythropoiesis (which increases iron absorption) and repeated transfusions. This iron accumulates in organs (heart, liver, endocrine glands), causing life-threatening complications like cardiomyopathy and cirrhosis. Chelation therapy with deferasirox prevents this secondary hemosiderosis. A is incorrect because phlebotomy would worsen the anemia in someone who's already severely anemic (Hb 6.8 g/dL). While it might reduce iron, it doesn't address the underlying ineffective erythropoiesis. B describes supportive care rather than preventive management. While transfusions may be needed acutely, they actually contribute to iron overload long-term without addressing the complications. D is completely wrong—giving more iron to someone with iron overload would be harmful. Erythropoietin won't correct the fundamental hemoglobin synthesis defect in thalassemia. Study tip: When you see microcytic anemia with paradoxically high iron studies, think thalassemia. The key insight is that iron overload in thalassemia comes from both increased absorption and transfusions, making chelation the cornerstone of preventing long-term complications.
A 58-year-old man with chronic kidney disease stage 4 is treated with darbepoetin alfa for anemia. After six months, his hemoglobin decreases from 10.2 to 6.9 g/dL. Mean corpuscular volume is unchanged. Reticulocyte count is very low, and leukocyte and platelet counts are normal. Serum iron studies are within normal limits. Which of the following is the most appropriate diagnostic study?
Explanation: When you encounter a patient on erythropoiesis-stimulating agents (ESAs) like darbepoetin alfa who develops severe anemia with low reticulocyte count, think about pure red cell aplasia (PRCA) caused by anti-erythropoietin antibodies. This is a well-recognized but rare complication of ESA therapy in CKD patients. The clinical picture here is classic: a CKD patient on darbepoetin who develops worsening anemia despite treatment, with an inappropriately low reticulocyte count (indicating bone marrow failure to produce red cells) but normal white cells and platelets. This selective red cell production failure, combined with the ESA exposure history, strongly suggests antibody-mediated PRCA. Option A is correct because serum anti-erythropoietin antibody testing is the specific diagnostic test for ESA-induced PRCA. These antibodies cross-react with both exogenous ESAs and endogenous erythropoietin, completely shutting down red cell production. Option B (bone marrow aspiration) would show the expected finding of absent erythroid precursors, but it's not the most specific test and doesn't identify the underlying cause. Option C (flow cytometry for PNH) is inappropriate since PNH causes hemolysis with elevated reticulocyte count, not decreased production. Option D (parvovirus B19 PCR) could cause similar findings but is far less likely in this clinical context of ESA therapy. Remember: ESA-induced PRCA is rare but serious. Always consider it when CKD patients on ESAs develop worsening anemia with low reticulocyte counts, and test for anti-erythropoietin antibodies as the definitive diagnostic study.
A 28-year-old woman at 30 weeks' gestation is found to have Hb 8.1 g/dL and MCV 71 fL. Ferritin is 8 ng/mL, serum iron is low, and total iron-binding capacity is high. She was intolerant of multiple oral iron formulations because of severe nausea. What is the best next step to correct her anemia before delivery?
Explanation: When you encounter iron deficiency anemia in pregnancy with oral iron intolerance, you need to consider the severity, gestational age, and safest parenteral iron options. This patient has moderate iron deficiency anemia (Hb 8.1 g/dL, MCV 71 fL, low ferritin) at 30 weeks with 10 weeks until delivery. Answer C is correct because intravenous iron sucrose is the safest and most effective parenteral iron for pregnant women who cannot tolerate oral iron. Low-molecular-weight iron sucrose has an excellent safety profile in pregnancy, doesn't require test dosing, and can effectively replenish iron stores over 1-2 infusion sessions. With 10 weeks remaining, there's adequate time for the iron to stimulate erythropoiesis and raise hemoglobin levels. Answer A is wrong because iron dextran, while effective, carries a higher risk of serious allergic reactions including anaphylaxis, making iron sucrose the preferred parenteral option in pregnancy. Answer B is incorrect because vitamin C supplementation alone won't address the fundamental problem - she cannot tolerate any oral iron formulations due to severe nausea, so enhancing absorption won't help. Answer D is wrong because her hemoglobin of 8.1 g/dL, while low, doesn't meet the threshold for urgent transfusion (typically <7 g/dL in stable patients). Transfusion carries unnecessary risks including infection, alloimmunization, and iron overload. Remember: For pregnant patients with iron deficiency anemia who can't tolerate oral iron, IV iron sucrose is first-line therapy. Reserve transfusions for severe anemia (<7 g/dL) or hemodynamic instability.
A 44-year-old man with ulcerative colitis presents with jaundice and dark urine 4 days after receiving piperacillin-tazobactam for cellulitis. Exam: scleral icterus, no splenomegaly. Labs: Hb 8.9 g/dL, MCV 92 fL, reticulocytes 12%, indirect bilirubin 4.2 mg/dL, LDH 520 U/L, haptoglobin low. Direct antiglobulin (Coombs) test is strongly positive for IgG and complement. What is the best initial treatment?
Explanation: When you encounter a patient with acute hemolysis and a positive direct antiglobulin test, you're dealing with autoimmune hemolytic anemia (AIHA). The key clinical clues here are the timing (4 days post-antibiotic), elevated indirect bilirubin, low haptoglobin, high reticulocyte count, and strongly positive Coombs test for both IgG and complement—all pointing to drug-induced warm AIHA. High-dose intravenous methylprednisolone (A) is correct because corticosteroids are the first-line treatment for warm AIHA. They work by suppressing autoantibody production and reducing macrophage-mediated hemolysis in the spleen. The "high-dose IV" specification is important because severe hemolysis requires aggressive immunosuppression. Option B is incomplete—while discontinuing the offending antibiotic is necessary, folic acid alone won't address the underlying autoimmune process causing ongoing hemolysis. Option C (exchange transfusion) is reserved for life-threatening cases when the hemoglobin is critically low or hemolysis is refractory to steroids. This patient's hemoglobin of 8.9 g/dL, while low, doesn't meet criteria for emergency intervention. Option D (IVIG) is typically used for cold agglutinin disease or as second-line therapy when steroids fail. Remember that drug-induced AIHA often presents within days of starting certain antibiotics (especially penicillins, cephalosporins). Always look for the temporal relationship between drug exposure and hemolysis onset. The treatment hierarchy is: discontinue the drug + high-dose steroids first, then escalate to IVIG, rituximab, or splenectomy if refractory.