Autoimmune disorders in pregnancy — MCQs

10 questions

A 29-year-old woman, gravida 1, para 0, at 33 weeks' gestation comes to her doctor for a routine visit. Her pregnancy has been uncomplicated. She has systemic lupus erythematosus and has had no flares during her pregnancy. She does not smoke cigarettes, drink alcohol, or use illicit drugs. Current medications include iron, vitamin supplements, and hydroxychloroquine. Her temperature is 37.2°C (98.9°F), pulse is 70/min, respirations are 17/min, and blood pressure is 134/70 mm Hg. She appears well. Physical examination shows no abnormalities. Ultrasound demonstrates fetal rhythmic breathing for > 30 seconds, amniotic fluid with deepest vertical pocket of 1 cm, one distinct fetal body movement over 30 minutes, and no episodes of extremity extension over 30 minutes. Nonstress test is reactive and reassuring. Which of the following is the next best step in management?

A 25-year-old G1P0 woman at an estimated gestational age of 9 weeks presents for her first prenatal visit following a positive home pregnancy test. She says she missed 2 periods but assumed it was due to stress at work. She has decided to continue with the pregnancy. Her past medical history is significant for migraine headaches, seizures, and asthma. She takes multiple medications for her condition. Physical examination is unremarkable. An ultrasound confirms a 9-week-old intrauterine pregnancy. Which of the following medications poses the greatest risk to the fetus?

A 29-year-old woman comes to the office with her husband because she has had 4 spontaneous abortions. Regarding her medical history, she was diagnosed with systemic lupus erythematosus 9 years ago, had a stroke 3 years ago, and was diagnosed with deep vein thrombosis in the same year. She has no relevant family history. Her vital signs include: heart rate 78/min, respiratory rate 14/min, temperature 37.5°C (99.5°F), and blood pressure 120/85 mm Hg. The physical examination is unremarkable. The complete blood count results are as follows: Hemoglobin 12.9 g/dL Hematocrit 40% Leukocyte count 8,500/mm3 Neutrophils 55% Bands 2% Eosinophils 1% Basophils 0% Lymphocytes 29% Monocytes 2% Platelet count 422,000/mm3 Her coagulation test results are as follows: Partial thromboplastin time (activated) 50.9 s Prothrombin time 13.0 s A VDRL test is done, and the result is positive. Mixing studies are performed, and they fail to correct aPTT. What is the most likely cause in this patient?

A 26-year-old G1P0 presents to her first obstetric visit after having a positive urine pregnancy test at home. Her last menstrual period was 9 weeks ago. She has no past medical history, but her mother has rheumatoid arthritis. The patient states that for several weeks, she has felt especially warm, even when her co-workers do not, and had muscle weakness. She also complains of mood swings and fatigue. At this visit, her temperature is 99.0°F (37.2°C), blood pressure is 140/81 mmHg, pulse is 106/min, and respirations are 17/min. Physical exam is notable for 3+ deep tendon reflexes bilaterally and 4/5 strength in both hips and shoulders. Ultrasound confirms the presence of a heart beat and shows a crown rump length that is consistent with a gestational age of 9 weeks and 3 days. Which of the following is the best therapy for this patient?

A 57-year-old immigrant from Nigeria presents to the emergency department for sudden, severe pain and swelling in her lower extremity. She was at a rehabilitation hospital when her symptoms became apparent. The patient has a past medical history of obesity, diabetes, bipolar disorder, and tonic-clonic seizures. Her current medications include metformin, insulin, lisinopril, and valproic acid. The patient is a prominent IV drug and alcohol user who has presented to the ED many times for intoxication. On physical exam you note anasarca and asymmetric lower extremity swelling. Based on the results of a doppler ultrasound of her swollen lower extremity, heparin is started. The patient is then transferred to the general medicine floor for continued management. Laboratory studies are shown below. Serum: Na+: 137 mEq/L K+: 5.5 mEq/L Cl-: 100 mEq/L HCO3-: 24 mEq/L Urea nitrogen: 22 mg/dL Ca2+: 5.7 mg/dL Creatinine: 1.7 mg/dL Glucose: 70 mg/dL The patient's presentation includes generalized edema (anasarca) along with laboratory abnormalities. What is the most likely underlying diagnosis that explains her overall clinical presentation?

A 51-year-old woman comes to the physician because of fatigue and progressive pain and stiffness in her hands for 3 months. She used to play tennis but stopped 1 month ago because of difficulties holding the racket and her skin becoming “very sensitive to sunlight.” Her last menstrual period was 1 year ago. She has diabetes mellitus controlled with insulin. She does not smoke or drink alcohol. Vital signs are within normal limits. The patient appears tanned. The second and third metacarpophalangeal joints of both hands are tender to palpation and range of motion is limited. Which of the following is the most appropriate next step in diagnosis?

A 30-year-old woman with a 1-year history of medically-managed Graves disease visits her endocrinologist to discuss her desire to become pregnant and whether pregnancy is safe with her medications. Her temperature is 98.4°F (36.9°C), blood pressure is 110/66 mmHg, pulse is 78/min, respirations are 12/min. The endocrinologist advises that the patient may pursue pregnancy, but first needs to be switched from methimazole to propylthiouracil for her Graves disease due to pregnancy safety considerations. Which of the following is a possible side effect of propylthiouracil that represents a greater risk compared to methimazole?

A 25-year-old woman presents to her physician with a missed mense and occasional morning nausea. Her menstrual cycles have previously been normal and on time. She has hypothyroidism resulting from Hashimoto thyroiditis diagnosed 2 years ago. She receives levothyroxine (50 mcg daily) and is euthyroid. She does not take any other medications, including birth control pills. At the time of presentation, her vital signs are as follows: blood pressure 120/80 mm Hg, heart rate 68/min, respiratory rate 12/min, and temperature 36.5℃ (97.7℉). The physical examination shows slight breast engorgement and nipple hyperpigmentation. The gynecologic examination reveals cervical softening and increased mobility. The uterus is enlarged. There are no adnexal masses. The thyroid panel is as follows: Thyroid stimulating hormone (TSH) 3.41 mU/L Total T4 111 nmol/L Free T4 20 pmol/L Which of the following adjustments should be made to the patient’s therapy?

A 25-year-old woman, gravida 2, para 1, at 25 weeks' gestation comes to the emergency department because of a 1-day history of fever and right-sided flank pain. During this period, she also had chills, nausea, vomiting, and burning on urination. Her last prenatal visit was 10 weeks ago. Pregnancy and delivery of her first child were uncomplicated. Her temperature is 39°C (102.2°F), pulse is 110/min, respirations are 20/min, and blood pressure is 110/70 mm Hg. Physical examination shows costovertebral angle tenderness on the right. The abdomen is soft and nontender, and no contractions are felt. Pelvic examination shows a uterus consistent in size with a 25-week gestation. Fetal heart rate is 170/min. Laboratory studies show: Leukocyte count 15,000/mm3 Urine Nitrite 2+ Protein 1+ Blood 1+ RBC 5/hpf WBC 500/hpf Blood and urine samples are obtained for culture and drug sensitivity. Which of the following is the most appropriate next step in management?

Q10

A 66-year-old woman comes to the physician because of a 1-week history of pruritic blister formation. Physical examination shows multiple 1–3 cm bullae on the palms, soles, lower legs, and inguinal folds. Gentle rubbing of the skin does not result in sloughing of the epidermis. Immunofluorescence studies of a perilesional skin biopsy specimen are most likely to show deposition of antibodies in which of the following areas?

Autoimmune disorders in pregnancy US Medical PG Practice Questions and MCQs

Question 1: A 29-year-old woman, gravida 1, para 0, at 33 weeks' gestation comes to her doctor for a routine visit. Her pregnancy has been uncomplicated. She has systemic lupus erythematosus and has had no flares during her pregnancy. She does not smoke cigarettes, drink alcohol, or use illicit drugs. Current medications include iron, vitamin supplements, and hydroxychloroquine. Her temperature is 37.2°C (98.9°F), pulse is 70/min, respirations are 17/min, and blood pressure is 134/70 mm Hg. She appears well. Physical examination shows no abnormalities. Ultrasound demonstrates fetal rhythmic breathing for > 30 seconds, amniotic fluid with deepest vertical pocket of 1 cm, one distinct fetal body movement over 30 minutes, and no episodes of extremity extension over 30 minutes. Nonstress test is reactive and reassuring. Which of the following is the next best step in management?

A. Administer corticosteroids and continue close monitoring (Correct Answer)
B. Perform cesarean delivery
C. Discontinue hydroxychloroquine and continue close monitoring
D. Induction of labor
E. Reassurance with expectant management

Explanation: ***Administer corticosteroids and continue close monitoring*** - The combination of a **nonreactive nonstress test (NST)** and an **amniotic fluid index (AFI) < 5 cm** (deepest vertical pocket of 1 cm) indicates **oligohydramnios** and potential fetal compromise, necessitating corticosteroid administration for lung maturity and close monitoring. - While the NST is reassuring, the oligohydramnios is a significant concern that warrants intervention to optimize fetal outcomes and prepare for potential preterm delivery. *Perform cesarean delivery* - This step is **overly aggressive** given the reactive nonstress test and stable maternal condition. - There are no immediate signs of **acute fetal distress** that would necessitate emergent delivery. *Discontinue hydroxychloroquine and continue close monitoring* - **Hydroxychloroquine** is safe and often continued during pregnancy for patients with systemic lupus erythematosus, as it helps prevent flares and is not associated with adverse fetal outcomes. - Discontinuing it without a clear indication could lead to a **maternal SLE flare**, which could be detrimental to both mother and fetus. *Induction of labor* - Induction of labor is not indicated at this gestational age (33 weeks) unless there is clear evidence of **significant fetal distress** or maternal complications. - While there is oligohydramnios, the **reactive NST** suggests sufficient fetal reserve to allow for corticosteroid administration to promote lung maturity first. *Reassurance with expectant management* - The finding of **oligohydramnios** (deepest vertical pocket of 1 cm) is a significant concern, as it is associated with increased risks of **cord compression**, fetal growth restriction, and adverse perinatal outcomes. - Therefore, expectant management without intervention would be **inappropriate** given this finding.

Question 2: A 25-year-old G1P0 woman at an estimated gestational age of 9 weeks presents for her first prenatal visit following a positive home pregnancy test. She says she missed 2 periods but assumed it was due to stress at work. She has decided to continue with the pregnancy. Her past medical history is significant for migraine headaches, seizures, and asthma. She takes multiple medications for her condition. Physical examination is unremarkable. An ultrasound confirms a 9-week-old intrauterine pregnancy. Which of the following medications poses the greatest risk to the fetus?

A. Valproic acid (Correct Answer)
B. Budesonide
C. Acetaminophen
D. Sumatriptan
E. Albuterol

Explanation: ***Valproic acid*** - **Valproic acid** is a known **teratogen** strongly associated with a high incidence of **neural tube defects** (e.g., spina bifida, anencephaly) when used during the first trimester of pregnancy. - It can also lead to other malformations, including cardiac defects and facial dysmorphism, as part of **fetal valproate syndrome**. *Budesonide* - **Budesonide** is an inhaled corticosteroid commonly used for asthma, considered a relatively **safe medication** during pregnancy (FDA pregnancy category B). - Studies have shown no increased risk of major congenital malformations with its use. *Acetaminophen* - **Acetaminophen** is a widely used analgesic and antipyretic considered **safe** for use throughout pregnancy at recommended doses. - There is no strong evidence linking acetaminophen to an increased risk of birth defects. *Sumatriptan* - **Sumatriptan** is a serotonin receptor agonist used for migraine headaches. It is generally considered to be of **low risk** during pregnancy (FDA pregnancy category C). - While some studies have suggested a minimal risk of certain birth defects, overall data supports its use when necessary. *Albuterol* - **Albuterol** is a short-acting beta-agonist used to treat asthma symptoms and is considered **safe** for use during pregnancy (FDA pregnancy category C). - There is no evidence of teratogenicity, and the benefits of controlling asthma outweigh the potential risks.

Question 3: A 29-year-old woman comes to the office with her husband because she has had 4 spontaneous abortions. Regarding her medical history, she was diagnosed with systemic lupus erythematosus 9 years ago, had a stroke 3 years ago, and was diagnosed with deep vein thrombosis in the same year. She has no relevant family history. Her vital signs include: heart rate 78/min, respiratory rate 14/min, temperature 37.5°C (99.5°F), and blood pressure 120/85 mm Hg. The physical examination is unremarkable. The complete blood count results are as follows: Hemoglobin 12.9 g/dL Hematocrit 40% Leukocyte count 8,500/mm3 Neutrophils 55% Bands 2% Eosinophils 1% Basophils 0% Lymphocytes 29% Monocytes 2% Platelet count 422,000/mm3 Her coagulation test results are as follows: Partial thromboplastin time (activated) 50.9 s Prothrombin time 13.0 s A VDRL test is done, and the result is positive. Mixing studies are performed, and they fail to correct aPTT. What is the most likely cause in this patient?

A. Antithrombin deficiency
B. Protein S deficiency
C. Protein C deficiency
D. Antiphospholipid syndrome (Correct Answer)
E. Factor V Leiden mutation

Explanation: ***Antiphospholipid syndrome*** - The patient's history of **recurrent spontaneous abortions**, **stroke**, **deep vein thrombosis**, and a **positive VDRL** (often falsely positive in APS) in the context of SLE strongly suggests antiphospholipid syndrome. - The **prolonged aPTT** that **fails to correct** with mixing studies indicates the presence of a circulating anticoagulant, such as the lupus anticoagulant, which is characteristic of APS. *Antithrombin deficiency* - Antithrombin deficiency typically presents with a tendency for **thrombosis**, but it would **not cause recurrent abortions** or a **false-positive VDRL**. - It would also **not affect aPTT** in the manner seen here (prolonged and unresponsive to mixing). *Factor V Leiden mutation* - **Factor V Leiden** is a common cause of **thrombophilia** and recurrent thrombosis. However, it is **not associated with recurrent abortions**, **false-positive VDRL**, or **prolonged aPTT**. - This mutation leads to resistance to inactivation by protein C, increasing clot risk, but does not affect coagulation tests like aPTT in this specific way. *Protein S deficiency* - Protein S deficiency, like Factor V Leiden, is associated with an increased risk of **venous thrombosis**. However, it is **not directly linked to recurrent abortions** or a **false-positive VDRL**. - It also does not typically cause a **prolonged aPTT** that fails to correct with mixing studies. *Protein C deficiency* - Protein C deficiency is a risk factor for **venous thrombosis** and can be associated with severe complications like **warfarin-induced skin necrosis**. - Similar to other hereditary thrombophilias, it does **not explain the recurrent abortions**, **false-positive VDRL**, or the **specific aPTT findings** observed in this patient.

Question 4: A 26-year-old G1P0 presents to her first obstetric visit after having a positive urine pregnancy test at home. Her last menstrual period was 9 weeks ago. She has no past medical history, but her mother has rheumatoid arthritis. The patient states that for several weeks, she has felt especially warm, even when her co-workers do not, and had muscle weakness. She also complains of mood swings and fatigue. At this visit, her temperature is 99.0°F (37.2°C), blood pressure is 140/81 mmHg, pulse is 106/min, and respirations are 17/min. Physical exam is notable for 3+ deep tendon reflexes bilaterally and 4/5 strength in both hips and shoulders. Ultrasound confirms the presence of a heart beat and shows a crown rump length that is consistent with a gestational age of 9 weeks and 3 days. Which of the following is the best therapy for this patient?

A. Methimazole
B. Prednisone
C. Propylthiouracil (Correct Answer)
D. Intravenous immunoglobulin
E. Radioactive thyroid ablation (I-131)

Explanation: ***Propylthiouracil*** - This patient presents with symptoms of **hyperthyroidism** (warmth, muscle weakness, mood swings, fatigue, tachycardia, hypertension, and hyperreflexia) exacerbated by pregnancy. **Propylthiouracil (PTU)** is the preferred treatment for hyperthyroidism in the **first trimester** of pregnancy due to a lower risk of teratogenicity compared to methimazole. - PTU works by **inhibiting thyroid hormone synthesis** and also blocks the peripheral conversion of T4 to T3. *Methimazole* - While an effective antithyroid drug, methimazole is generally **avoided in the first trimester** of pregnancy due to its association with rare but severe birth defects, such as **aplasia cutis** and choanal atresia. - It becomes the preferred treatment in the second and third trimesters if antithyroid medication is still required, due to a lower risk of liver toxicity compared to PTU. *Prednisone* - **Prednisone** is a corticosteroid used to manage inflammatory conditions and suppress the immune system; it is **not a primary treatment for hyperthyroidism**. - While it can be used in severe cases of thyroid storm to reduce peripheral conversion of T4 to T3, it is not the initial therapy for uncomplicated gestational hyperthyroidism. *Intravenous immunoglobulin* - **Intravenous immunoglobulin (IVIG)** is an immune modulator used in various autoimmune conditions but has **no direct role in the treatment of hyperthyroidism**. - It works by providing antibodies and modulating the immune response, which is not the primary mechanism needed to control excessive thyroid hormone production. *Radioactive thyroid ablation (I-131)* - **Radioactive iodine ablation** is absolutely **contraindicated in pregnancy** as it can cross the placenta and destroy the fetal thyroid gland, leading to **fetal hypothyroidism**. - This treatment is reserved for non-pregnant individuals with hyperthyroidism who fail antithyroid medications or have recurrent disease.

Question 5: A 57-year-old immigrant from Nigeria presents to the emergency department for sudden, severe pain and swelling in her lower extremity. She was at a rehabilitation hospital when her symptoms became apparent. The patient has a past medical history of obesity, diabetes, bipolar disorder, and tonic-clonic seizures. Her current medications include metformin, insulin, lisinopril, and valproic acid. The patient is a prominent IV drug and alcohol user who has presented to the ED many times for intoxication. On physical exam you note anasarca and asymmetric lower extremity swelling. Based on the results of a doppler ultrasound of her swollen lower extremity, heparin is started. The patient is then transferred to the general medicine floor for continued management. Laboratory studies are shown below. Serum: Na+: 137 mEq/L K+: 5.5 mEq/L Cl-: 100 mEq/L HCO3-: 24 mEq/L Urea nitrogen: 22 mg/dL Ca2+: 5.7 mg/dL Creatinine: 1.7 mg/dL Glucose: 70 mg/dL The patient's presentation includes generalized edema (anasarca) along with laboratory abnormalities. What is the most likely underlying diagnosis that explains her overall clinical presentation?

A. Liver failure
B. Nephrotic syndrome (Correct Answer)
C. Antithrombin III deficiency
D. Prothrombin gene mutation
E. Factor V Leiden

Explanation: ***Nephrotic syndrome*** - The patient presents with **anasarca** (generalized edema), **asymmetric lower extremity swelling**, and laboratory findings consistent with **nephrotic syndrome**. - Classic features present: **anasarca** (from hypoalbuminemia and fluid retention), **hypercoagulable state** leading to DVT (loss of antithrombin III in urine), and **renal dysfunction** (elevated creatinine 1.7 mg/dL). - The **hypocalcemia (5.7 mg/dL)** is explained by low albumin—total calcium appears low because ~40% of serum calcium is albumin-bound; ionized calcium is likely normal. - Nephrotic syndrome is characterized by: heavy proteinuria (>3.5 g/day), hypoalbuminemia, hyperlipidemia, and edema—this patient's presentation fits this diagnosis. - Risk factors include diabetes (diabetic nephropathy is a common cause of nephrotic syndrome in adults). *Liver failure* - Although **anasarca** and **edema** can occur in liver failure due to decreased albumin synthesis and portal hypertension, the laboratory values do not show typical signs of severe hepatic dysfunction (e.g., elevated transaminases, bilirubin, or prolonged INR). - The **elevated creatinine** and **hypercoagulable state with DVT** point more towards a primary renal issue rather than liver failure. - Liver failure typically causes **hypocoagulability**, not the hypercoagulability seen here. *Antithrombin III deficiency* - This is a **hereditary thrombophilia** that increases the risk of **venous thromboembolism**, which could explain the DVT. - However, it does **not explain** the patient's **anasarca**, **hypocalcemia**, **elevated creatinine**, or generalized fluid retention. - This would be a complication of nephrotic syndrome (acquired AT-III deficiency from urinary loss), not the primary diagnosis. *Prothrombin gene mutation* - This is another **genetic thrombophilia** (G20210A mutation) that increases the risk of **blood clots**. - Similar to Antithrombin III deficiency, it accounts for DVT risk but **fails to explain** the widespread edema, electrolyte abnormalities, and renal dysfunction. *Factor V Leiden* - The **Factor V Leiden mutation** is the most common inherited cause of **thrombophilia**, predisposing individuals to venous thromboembolism. - While relevant to explaining DVT in isolation, it does **not explain** the patient's severe generalized edema, hypocalcemia, or renal impairment—all of which are key to this clinical presentation.

Question 6: A 51-year-old woman comes to the physician because of fatigue and progressive pain and stiffness in her hands for 3 months. She used to play tennis but stopped 1 month ago because of difficulties holding the racket and her skin becoming “very sensitive to sunlight.” Her last menstrual period was 1 year ago. She has diabetes mellitus controlled with insulin. She does not smoke or drink alcohol. Vital signs are within normal limits. The patient appears tanned. The second and third metacarpophalangeal joints of both hands are tender to palpation and range of motion is limited. Which of the following is the most appropriate next step in diagnosis?

A. Synovial fluid analysis
B. Testing for parvovirus B19 antibodies
C. Testing for rheumatoid factors
D. Testing for anti-nuclear antibodies
E. Iron studies (Correct Answer)

Explanation: ***Iron studies*** - The patient's presentation with **"tanned" appearance**, **diabetes mellitus**, and **arthropathy specifically involving the 2nd and 3rd metacarpophalangeal joints** is the **classic triad of hemochromatosis** (hereditary iron overload). - The bronze/tan skin pigmentation results from **iron deposition in the skin**, while diabetes occurs from **iron deposition in the pancreas** ("bronze diabetes"). - **MCP 2 and 3 joint involvement** is pathognomonic for hemochromatosis arthropathy, distinguishing it from other arthritides. - **Iron studies** (serum ferritin and transferrin saturation) are the most appropriate initial diagnostic tests, typically showing **elevated ferritin (>200 ng/mL in women) and transferrin saturation >45%**. - Early diagnosis is crucial as hemochromatosis is treatable with phlebotomy, preventing progression to cirrhosis and cardiac complications. *Testing for anti-nuclear antibodies* - While **photosensitivity** could suggest **systemic lupus erythematosus (SLE)**, the patient lacks other characteristic SLE features (malar rash, oral ulcers, serositis). - The **"tanned" appearance** is not typical of photosensitivity, which usually manifests as a **rash or erythema with sun exposure**, not generalized hyperpigmentation. - The **specific involvement of MCP 2 and 3 joints** is more characteristic of hemochromatosis than SLE, which typically has a more diffuse polyarticular pattern. - ANA testing would be appropriate if other SLE features were present, but the constellation of findings here points to iron overload. *Synovial fluid analysis* - This test is performed to evaluate for **septic arthritis**, **crystal arthropathy (gout, pseudogout)**, or other inflammatory conditions when there is **acute monoarticular** or **oligoarticular** involvement. - The patient's **chronic, symmetrical polyarticular** presentation and systemic features make a systemic metabolic disorder (hemochromatosis) more likely than conditions requiring synovial fluid analysis as the initial diagnostic step. *Testing for parvovirus B19 antibodies* - **Parvovirus B19** can cause acute arthropathy mimicking rheumatoid arthritis, typically following a viral prodrome. - However, the **3-month chronicity**, **diabetes**, and **bronze pigmentation** are not explained by parvovirus infection, making this an unlikely diagnosis. *Testing for rheumatoid factors* - While **rheumatoid arthritis (RA)** can present with symmetrical small joint arthritis, it typically involves **PIP and MCP joints more diffusely**, not specifically MCP 2 and 3. - RA does not explain the **tanned appearance** or the specific association with **diabetes mellitus** seen in this patient. - The MCP 2 and 3 predilection is a distinguishing feature of hemochromatosis arthropathy.

Question 7: A 30-year-old woman with a 1-year history of medically-managed Graves disease visits her endocrinologist to discuss her desire to become pregnant and whether pregnancy is safe with her medications. Her temperature is 98.4°F (36.9°C), blood pressure is 110/66 mmHg, pulse is 78/min, respirations are 12/min. The endocrinologist advises that the patient may pursue pregnancy, but first needs to be switched from methimazole to propylthiouracil for her Graves disease due to pregnancy safety considerations. Which of the following is a possible side effect of propylthiouracil that represents a greater risk compared to methimazole?

A. Thyroid storm
B. Agranulocytosis
C. Fulminant hepatic necrosis (Correct Answer)
D. Skin rash
E. Aplastic anemia

Explanation: ***Fulminant hepatic necrosis*** - Propylthiouracil (PTU) carries a **black box warning** for severe liver injury, including **fulminant hepatic necrosis**, which is a greater risk compared to methimazole. - This risk is particularly relevant in the context of pregnancy, as PTU is often preferred in the first trimester due to lower teratogenic risk, but its hepatotoxicity must be closely monitored. *Thyroid storm* - **Thyroid storm** is a life-threatening exacerbation of hyperthyroidism and is not a direct side effect of antithyroid medications like PTU or methimazole. - It is a complication of inadequately treated or untreated hyperthyroidism. *Agranulocytosis* - **Agranulocytosis** is a rare but serious side effect of both propylthiouracil and methimazole. - While it is a concern, the risk of fulminant hepatic necrosis is specifically highlighted as being higher with PTU. *Skin rash* - **Skin rash** is a common and usually mild side effect that can occur with both methimazole and propylthiouracil. - It is not typically considered a more severe or distinguishing risk for PTU compared to methimazole. *Aplastic anemia* - **Aplastic anemia** is an extremely rare but severe side effect that can be associated with antithyroid drugs, including both PTU and methimazole. - Although serious, the risk of fulminant hepatic necrosis is a more specifically emphasized and distinct concern for PTU.

Question 8: A 25-year-old woman presents to her physician with a missed mense and occasional morning nausea. Her menstrual cycles have previously been normal and on time. She has hypothyroidism resulting from Hashimoto thyroiditis diagnosed 2 years ago. She receives levothyroxine (50 mcg daily) and is euthyroid. She does not take any other medications, including birth control pills. At the time of presentation, her vital signs are as follows: blood pressure 120/80 mm Hg, heart rate 68/min, respiratory rate 12/min, and temperature 36.5℃ (97.7℉). The physical examination shows slight breast engorgement and nipple hyperpigmentation. The gynecologic examination reveals cervical softening and increased mobility. The uterus is enlarged. There are no adnexal masses. The thyroid panel is as follows: Thyroid stimulating hormone (TSH) 3.41 mU/L Total T4 111 nmol/L Free T4 20 pmol/L Which of the following adjustments should be made to the patient’s therapy?

A. Increase levothyroxine dosage by 20%–30% (Correct Answer)
B. Decrease levothyroxine dosage by 30%
C. Discontinue levothyroxine
D. The patient is euthyroid, so no adjustments should be made
E. Increase levothyroxine dosage by 5% each week up to 50%

Explanation: ***Increase levothyroxine dosage by 20%–30%*** - The patient's symptoms (missed menses, nausea, breast changes, enlarged uterus, cervical changes) are highly suggestive of **pregnancy**. During pregnancy, **thyroid hormone requirements increase significantly** due to increased levels of **thyroid-binding globulin (TBG)** stimulated by estrogen, and the production of **human chorionic gonadotropin (hCG)** which has TSH-like activity. - The recommended management for pregnant women with hypothyroidism is to **increase the levothyroxine dose by approximately 25-50%** and monitor TSH and free T4 levels every 4-6 weeks to maintain a TSH level within the goal range for pregnancy (typically <2.5 mU/L in the first trimester). *Decrease levothyroxine dosage by 30%* - Decreasing levothyroxine would lead to **hypothyroidism**, which is detrimental in pregnancy and associated with adverse outcomes such as **preeclampsia**, **gestational hypertension**, **low birth weight**, and **neurocognitive impairment** in the offspring. - Thyroid hormone requirements increase, not decrease, during pregnancy. *Discontinue levothyroxine* - **Discontinuing levothyroxine** would result in severe hypothyroidism, posing significant risks to both the mother and the developing fetus. - Hypothyroidism must be treated throughout pregnancy to ensure proper fetal development. *The patient is euthyroid, so no adjustments should be made* - While the patient's thyroid panel currently shows euthyroid values (TSH 3.41 mU/L is within normal range but slightly elevated for first-trimester pregnancy goals), the **onset of pregnancy** rapidly increases thyroid hormone demand. - Failure to adjust the dose can lead to **maternal and fetal hypothyroidism** as pregnancy progresses, even if the patient is currently euthyroid. *Increase levothyroxine dosage by 5% each week up to 50%* - A gradual increase of 5% each week may be too slow and insufficient to meet the rapidly increasing thyroid hormone demands of early pregnancy. - The standard recommendation is to make a more substantial initial adjustment (20-30%) as soon as pregnancy is confirmed, followed by close monitoring and further adjustments.

Question 9: A 25-year-old woman, gravida 2, para 1, at 25 weeks' gestation comes to the emergency department because of a 1-day history of fever and right-sided flank pain. During this period, she also had chills, nausea, vomiting, and burning on urination. Her last prenatal visit was 10 weeks ago. Pregnancy and delivery of her first child were uncomplicated. Her temperature is 39°C (102.2°F), pulse is 110/min, respirations are 20/min, and blood pressure is 110/70 mm Hg. Physical examination shows costovertebral angle tenderness on the right. The abdomen is soft and nontender, and no contractions are felt. Pelvic examination shows a uterus consistent in size with a 25-week gestation. Fetal heart rate is 170/min. Laboratory studies show: Leukocyte count 15,000/mm3 Urine Nitrite 2+ Protein 1+ Blood 1+ RBC 5/hpf WBC 500/hpf Blood and urine samples are obtained for culture and drug sensitivity. Which of the following is the most appropriate next step in management?

A. Inpatient treatment with intravenous ceftriaxone (Correct Answer)
B. Perform a renal ultrasound
C. Outpatient treatment with oral ciprofloxacin
D. Inpatient treatment with intravenous ampicillin and gentamicin
E. Admit the patient and request an emergent obstetrical consult

Explanation: ***Inpatient treatment with intravenous ceftriaxone*** - The patient presents with classic signs of **pyelonephritis** (fever, flank pain, nausea, vomiting, CVA tenderness) in pregnancy, which warrants **inpatient admission** and **IV antibiotics** to prevent complications such as sepsis, preterm labor, and fetal compromise. - **Ceftriaxone** is a broad-spectrum cephalosporin that is safe and effective in pregnancy for treating urinary tract infections, including pyelonephritis. *Perform a renal ultrasound* - While a **renal ultrasound** may be considered in cases of persistent fever after 48-72 hours of antibiotic therapy or if there's suspicion of obstruction or abscess, it is **not the immediate next step**. - The priority is to initiate antibiotics promptly to treat the acute infection and prevent further complications. *Outpatient treatment with oral ciprofloxacin* - **Outpatient treatment** is inappropriate for **pyelonephritis in pregnancy** due to the high risk of complications for both the mother and the fetus. - **Ciprofloxacin** (a fluoroquinolone) is generally **contraindicated in pregnancy** because of potential adverse effects on fetal cartilage development. *Inpatient treatment with intravenous ampicillin and gentamicin* - Although **ampicillin and gentamicin** are effective for many UTIs and safe in pregnancy, they are often reserved for cases where local resistance patterns favor this combination or as a second-line option. - **Ceftriaxone** is a preferred first-line empiric choice for pyelonephritis in pregnancy due to its broad coverage and once-daily dosing. *Admit the patient and request an emergent obstetrical consult* - While admitting the patient is correct, **immediately requesting an emergent obstetrical consult** is premature as the primary issue is an acute infection requiring medical management. - Obstetrics consultation is important in managing high-risk pregnancies or complications like preterm labor, but antibiotics for pyelonephritis should be initiated first, and then an obstetrician can be consulted for comanagement.

Question 10: A 66-year-old woman comes to the physician because of a 1-week history of pruritic blister formation. Physical examination shows multiple 1–3 cm bullae on the palms, soles, lower legs, and inguinal folds. Gentle rubbing of the skin does not result in sloughing of the epidermis. Immunofluorescence studies of a perilesional skin biopsy specimen are most likely to show deposition of antibodies in which of the following areas?

A. In dermal papillae
B. Between epidermal keratinocytes
C. No staining
D. In dermal vessel walls
E. At the dermoepidermal junction (Correct Answer)

Explanation: ***At the dermoepidermal junction*** - This presentation of **tense bullae** on flexural surfaces in an elderly patient, with a negative **Nikolsky's sign** (no epidermal sloughing with rubbing), is classic for **bullous pemphigoid**. - **Direct immunofluorescence** in bullous pemphigoid typically reveals linear deposits of **IgG** and/or **C3** at the **dermoepidermal junction (basement membrane zone)**. *In dermal papillae* - Deposition in dermal papillae is characteristic of **dermatitis herpetiformis**, which typically presents with intensely pruritic papules and vesicles, often on extensor surfaces. - The morphology and distribution of lesions in this patient (large bullae on palms, soles, inguinal folds) are not consistent with dermatitis herpetiformis. *Between epidermal keratinocytes* - Deposition of autoantibodies (IgG) between epidermal keratinocytes is a hallmark of **pemphigus vulgaris**, resulting in suprabasal blistering and a positive **Nikolsky's sign**. - This patient exhibits **tense bullae** and a **negative Nikolsky's sign**, which rules out pemphigus vulgaris. *No staining* - The presence of pruritic blister formation in an elderly patient strongly suggests an autoimmune bullous disease, for which direct immunofluorescence is a key diagnostic tool. - A lack of staining would indicate a non-immunological cause of blistering or a different type of dermatological condition, which is unlikely given the clinical picture. *In dermal vessel walls* - Immune complex deposition in dermal vessel walls is characteristic of diseases like **leukocytoclastic vasculitis**, which presents with palpable purpura rather than tense bullae. - The clinical presentation of pruritic bullae in this patient is inconsistent with a vasculitis.

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