Explanations for the 2020-2022 Official Step 2 CK Practice Questions

Update: The March 2021 pdf is identical outside of some minor formatting changes.

Update: The April 2022 pdf also seems to be unchanged.

The NBME released a completely new set of questions in March 2020, which was the first major update since basically 2015.

The 2019 set, which is completely different, is available and explained here for more free questions!

These are in the order of the PDF linked above.

Block 1

1. C – While you may have initially been thinking of alcohol withdrawal, the case presents you with signs/symptoms of decompensated cirrhosis including hepatic encephalopathy from hyperammonemia (AMS, asterixis). Treatment is oral lactulose, which helps clear ammonia via the power of horrible diarrhea.
2. F – Keep in mind that “not all that wheezes is asthma.” Wheezing is a sign of obstructive lung disease, not a diagnostic feature, so consider asthma alternatives in adults. Hemoptysis and fever help change the game. Eosinophilic granulomatosis with polyangiitis (Churg-Strauss) and granulomatosis with polyangiitis (née Wegener’s) both cause lung disease, but did you know they can also cause peripheral neuropathy? The former over the latter more commonly has neuropathy and presents with asthma, but the latter can easily do the same. ANCA can be positive in both and helps confirm the diagnosis of systemic vasculitis as a unifying cause.
3. D – Urinary retention due to pelvic organ prolapse. Multiple vaginal deliveries are the risk factor/cause.
4. D – This patient has neutropenic fever. Methimazole can cause agranulocytosis.
5. A – Concerning for meningitis. Yes, even with abdominal pain, which can be so severe that it can mimic appendicitis. Remember that splenectomy status predisposes to infection with encapsulated organisms such as meningococcus. This may also be purposefully vague, as in real life this could also certainly be an abdominal process like actual appendicitis, for which you might get an appendix ultrasound or CT of the abdomen/pelvis in addition to the key testing point of starting empiric antibiotics in an asplenic patient, but that’s not an answer choice.*
6. A – Also meningitis. There’s a vaccine for that, which everyone in college is supposed to get.
7. D – Every pregnant patient gets tested for HIV during routine initial prenatal workup/testing as well as again during the third trimester.
8. E – Quitters gonna quit.
9. C – When old men stop peeing so well, consider the poorly designed straw-crusher, the prostate. Chronic outlet obstruction isn’t so great, but it also predisposes to acute prostatitis which in turn can further worsen said obstruction when the gland swells. First thing to do is see how much the gentlemen is backed up, which in turn tells us if he has earned catheterization. Old people and UTIs go together like [insert your own clever comparison].
10. E – That’s a septic joint, not just RA (RA is a risk factor). Full-blown fever and intraarticular pus.
11. C – We have event rates of 35% for EST and 15% for EPCS, and the number needed to treat (NNT) is the inverse of the absolute risk reduction or 1/ARR. ARR = Control event rate minus experiment event rate. So, we have ARR = 0.35 – 0.15 = 0.2, and therefore NNT = 1/0.2 = 5. Boom, math.
12. B – This is a great RCT. The issue is that EPCS is a specialized treatment not as widely and emergently available as the usual GI-doc on call.
13. B – It works. P < 0.001 for that parameter.
14. A – With treatment adherence, most HIV-positive individuals will die of the same things as the rest of us: the American way of life.
15. A – Initial treatment for inadequate sleep and various types of “insomnia” is sleep hygiene modification. Certainly, her smoking and nicotine activation aren’t helping, but there’s no such therapy as “setting a date for smoking cessation.” Americans are terrible with sleep, and many who struggle are doing all the wrong things like using electronic devices late in the evening, dealing with neverending light pollution, caffeine and cigarettes too late in the day, going to bed too late, blah blah blah.
16. B – Rapidly progressive dementia (with or without personality changes, psychiatric disturbances, and sudden/jerky movements) raises the possibility of Creutzfeldt-Jakob disease, for which CSF protein 14-3-3 is an important marker.
17. C – Slow submersion warming is key when dealing with frostbite. Air and towels/dressings are poor conductors of temperature.
18. D – She has thrombocytopenia, likely related to a lupus flare given underlying SLE as well as evidence of active arthritis with joint effusions. Thrombocytopenia in lupus can occur via an ITP-like autoantibody phenomenon. In fact, some patients with lupus initially present with immune thrombocytopenic purpura (ITP) prior to developing other lupus symptoms. Whether a lupus flare or true ITP in the setting of other autoimmune conditions, the initial treatment of an active bout is prednisone. Refractory cases of ITP can be treated by splenectomy.
19. B – Mitral regurgitation explains the soft S1 and holosystolic murmur loudest at the apex. Acute heart failure with pulmonary edema. In the context of a recent URI, this is most concerning for viral myocarditis. Rheumatic fever can also present with carditis, but in this case, the patient has otherwise recovered from other symptoms.
20. E – Bilious vomiting in the newborn includes the full differential (duodenal atresia, midgut malrotation and volvulus, jejunoileal atresia, meconium ileus and necrotizing enterocolitis), but rapidly-ill bilious vomiting combined with fever, distension, and tenderness after a  few days to a week or so is most concerning for midgut volvulus. Most other causes present soon after birth with the exception of necrotizing enterocolitis, usually affecting premature babies within a couple of weeks after birth. Diagnosis with upper GI.
21. A – Using the most expensive things isn’t always a great use of limited resources. In a very elderly patient with dementia and multiple medical comorbidities, you probably don’t need the most long-lasting most-expensive stents when the long-term survival prospects of the patient are dismal.
22. A – This is a potentially fatal decision. Patients can choose to deny care, but when someone is making the “wrong” choice, it’s important to make sure they have the capacity to do so: do they understand their situation, their options, and the possible consequences of their actions? If so, that’s fine.
23. E – The banana bag! You might be thinking of Flumazenil to reverse his benzo use, but be wary of using in an otherwise stable chronic user as this can precipitate seizures. He’s also probably drunk, but that we’ll just wait out. In this case, he’s awake and protecting his airway but he’s encephalopathic. When an alcoholic is encephalopathic, think Wernicke’s and give thiamine. Even if they’re just plain ole drunk you’re not going to hurt them.
24. B – These are the signs and symptoms of testicular torsion, a surgical emergency.
25. C – This is a diffuse pontine glioma, a death sentence. You don’t really need to know that, because the stem tells you of the poor prognosis. Whenever someone is presented with a serious diagnosis, any treatment discussion starts with establishing a baseline understanding of the disease process and then discussing goals of care.
26. B – We have a middle-aged black female as the setup. Pulmonary disease with CXR showing bilateral hilar adenopathy. She has cutaneous involvement of the face. Cutaneous involvement is present in 1/3 of systemic cases but can have a variety of appearances.
27. E – Statin-myopathy is assessed laboratorily with serum CK.
28. C – Source control followed by symptomatic relief. Have you seriously ever heard of anyone doing any of that other crazy stuff?
29. A – ECT works. It works really well, and it works really fast. This gentleman is wasting away and is unable to care for himself.
30. E – USPSTF recommends clinicians screen all adults aged 18-79 for hepatitis C infection.
31. D – Serum sickness-like reaction, relatively common with penicillin. If someone has an antibiotic allergy/complication, just use another antibiotic.
32. B – People low on the totem pole aren’t going to feel comfortable speaking up unless encouraged.
33. D – If you thought that looked like a squamous cell carcinoma, that’s because it is. A keratoacanthoma is the name of the erupting-volcano variant, though some keratoacanthomas will resolve spontaneously and others progress to invasive cancer.
34. D – USPSTF recommends all men 35 and older (women 45 and older) are screened for lipid disorders, and age 20+ for those with increased risk of CAD.
35. C – Routine imaging for pyelonephritis at presentation is not generally helpful. But CT imaging for those who do not respond to antibiotics is indicated to evaluate for complicating factors like renal abscess or nephrolithiasis that cannot be treated with antibiotics alone.
36. D – We can simplify this with the general framework that if significant hypotension doesn’t resolve with volume repletion, then we move on to pressors.
37. A – She is currently prediabetic. But not for long.
38. D – No lying.
39. C – Acute kidney injury with volume overload, presumably from the ACE-inhibitor.
40. C – Hereditary weak bones, mobile joints, and hearing loss are a good fit for osteogenesis imperfecta. Scoliosis and short stature are also common, particularly in more severe cases.

Block 2

41. B – The goal is to hopefully make sure she is safe (and if she is at-risk for partner abuse to provide her with resources). On a related note, unlike for children and elders, there is no reporting mechanism for partner abuse.
42. B – He’s got a cyanosis-level from an aortic embolism. His floppy, akinetic LV is the risk factor for thrombus generation, which was subsequently squeezed out and lodged distally. The other choices would not result in isolated symmetric lower body symptoms.
43. B – This is all to say he has chronic lung disease. He has findings of possible fibrosis on CXR and a history certainly concerning for smoking-related lung disease. HRCT will tell us if he has a pattern characteristic of UIP (e.g. idiopathic pulmonary fibrosis) or something potentially more treatable like NSIP or just run-of-the-mill COPD.
44. B – Recurrent vomiting results in a hypokalemic hypochloremic metabolic alkalosis (i.e. you lose acid and keep having to make more).
45. C – CTs evaluate the kidneys, but they do a very poor job evaluating the bladder. Direct cystoscopy is needed to clear the lower urinary tract of an underlying bleeding mass. Smokers are at increased risk of bladder cancer.
46. E – “Bone broke must fix.”
47. D – Hypertension is the number 1 risk factor for stroke. Additionally, while smoking cessation is also important, it takes years for the deleterious vascular effects of smoking to normalize. Antihypertension therapy is needed right now and has a much higher likelihood of success than stopping someone’s habit of a lifetime.
48. B – They are presumably trying to demonstrate that she has an acute viral-type syndrome given the flu-like illness with fever, muscle aches, and generalized misery. COVID-19 wasn’t an answer choice. Note the CXR says “interstitial infiltrates,” which is the Step code phrase for atypical infection (as opposed to consolidative pneumonia).
49. D – Dyslexia is one of several different learning disorders.
50. C – Inflamed painful infected external auditory canal is consistent with otitis externa. Earplugs are a risk factor, both from microabrasion trauma and/or from contact dermatitis.
51. C – Most acute sinusitis is viral, not bacterial. Most antibiotic use for sinusitis is futile. Nasal irrigation and decongestant therapy are the hallmark treatments to relieve drainage pathway obstruction and give the body the ability to drain secretions properly.
52. D – Children with VATER often have tracheomalacia (part of the T), which can be associated with TEF and esophageal atresia. Tracheomalacia results in dynamic airway obstruction due to airway collapse on expiration (greater when forced).
53. D – Chest pain in the setting of a recent URI and with the low-grade ST elevation in multiple leads is the classic setting for pericarditis. The scratchy sound is the “pericardial rub.” Echo will assess for a pericardial effusion (and its size/significance), pericardial thickening, as well as assess for overall cardiac function.
54. B – Idiopathic and viral pericarditis treatment is anti-inflammatory. Data show that Colchicine is a useful NSAID adjunct for all pericarditis treatment, not just recurrent or prolonged cases as was once commonly assumed.
55. D – He is not safe, you have enough information to act.
56. E – She has multiple sclerosis. Clinically, neurologic lesions/deficits separated in time and space. MRI can show us evidence of demyelination in the brain to go along with her optic neuritis. These features are more important than oligoclonal bands in the CSF.
57. E – She has no significant cognitive deficits and is thus still normal enough to not require a dementia workup. In real life, I have plenty of evidence she’d get that MRI.
58. D – Serotonin syndrome. The most important next step is to remove the offending serotonergic agents.
59. E – He would seem to be psychotic. While people with schizophrenia or delusional disorders are on average no more dangerous than other folks, safety is paramount. Danger to self or others and all that.
60. A – Vesicular rash in the immune-compromised is a common scenario for Varicella-Zoster reactivation. Visceral zoster involvement can result in severe pain that can be mistaken for an acute abdomen. Treatment with acyclovir or valacyclovir.
61. E – Vulvar cancer is rarer than cervical cancer but has many of the same risk factors including HPV. Another risk factor worth knowing is lichen sclerosis, which results in thin itchy vulvar skin.
62. E – Thyroid nodules are best evaluated by thyroid ultrasound. While larger nodules (>1.5 cm) are more likely to be malignant, there are plenty of very large completely benign nodules that would be inappropriate to biopsy.
63. E – AZT monotherapy during the intrapartum and postpartum period (in addition to maternal therapy throughout pregnancy) is recommended for all neonates of HIV-positive mothers to reduce transmission and is very effective (less than 1%) for mothers who achieved viral suppression. Presumptive HIV therapy is recommended for infants whose mothers didn’t or who had their primary infection during pregnancy or while nursing.
64. B – Prolactinomas (pituitary adenomas that secrete prolactin and as a result can cause amenorrhea/infertility/lactation) can be treated with dopamine agonists like cabergoline. This is because dopamine normally inhibits pituitary prolactin production. In many cases, tumors can completely involute with pharmacologic therapy alone.
65. E – This constellation of symptoms in a premature infant by around two weeks of life is concerning for NEC. The diagnosis is commonly made with abdominal radiographs, which can demonstrate bowel dilation and pneumatosis (and when more severe, frank pneumoperitoneum).
66. E – You can’t turf out emergency care that you are equipped to perform just because a patient can’t pay. Dumping is why EMTALA was created in the first place.
67. E – Pseudoseizures are diagnosed in EMUs with video EEG. You match the behavior with the EEG to see if there are epileptiform discharges that correspond to the episodes. While this is clearly absurd for an epileptic seizure (impossible movements, insane duration, and no postictal period), there are plenty of cases of bizarre seizure patterns that are VEEG proven.
68. D – Pleurisy (or potentially costochondritis) secondary associated with a URI, either way, treat with NSAIDs.
69. B – This person recently had normal cycles, essentially excluding A and C. We have no reason to suspect D. And the normal prolactin excludes E. Hypothalamic hypogonadism can have many causes, among them chronic stress and anxiety, as seen in patients with eating disorders, sufferers of PTSD, etc.
70. B – Menopause. Elevated FSH and no period for over a year confirm.
71. E – Penicillin prophylaxes is indicated in all children with sickle cell younger than 5 to prevent severe pneumococcal infection.
72. B – Jaundice in the newborn. When unconjugated, typically “physiologic,” with two common causes breastfeeding jaundice (due to insufficient intake) and breast-milk jaundice. In this case, however, the bilirubinemia is conjugated (“direct”), which suggests cholestasis. Ultrasound is needed to evaluate the liver and biliary system.
73. D – Relentless dry cough is a common reaction to ACE inhibitor therapy.
74. E – Opioids result in floppy babies who don’t breathe well, just like they do in adults.
75. D – Obstructive sleep apnea can result in ADHD-like symptoms, irritability, and poor growth. The snoring is a tip-off, and tonsil/adenoid enlargement is the main cause of intermittent airway obstruction during sleep in children.
76. D – Lisfranc (tarso-metastarsal) dislocations in the setting of Charcot arthropathy (diabetic neuropathic joint). Initial treatment for acute Charcot joint is immobilization to prevent progressive deformity.
77. C – Parents don’t get to withhold lifesaving emergency treatment from their children, religion or not.
78. C – Cyanotic newborn with a single S2 is suggestive of a truncus arteriosis congenital heart defect (a VSD combined with a single ventricular outflow track comprising both the pulmonary and systemic circulation). The pulmonary circulation is thus torrential resulting in pulmonary edema. Like other CHD that result in early cyanosis, these patients are ductus-dependent for oxygenation mixing and should receive prostaglandin to maintain a PDA.
79. A – Vasospastic angina (formerly known as Prinzmetal angina). Rest angina/chest pain rapidly relieved by nitrates in a patient without coronary disease. Commonly treated with calcium channel blockers. An alternative possibility that would also yield the correct answer is esophageal spasm, but there’s been no workup to support that etiology save for the presence of non-CAD-related chest pain.
80. D – There is AV concordance (all QRS have a preceding P wave), but we have intermittent dropped beats consistent with a second-degree AV block. The PR-interval of the conducted beats is always the same, so we have Mobitz 2. Progressively lengthening PR-interval prior to a dropped QRS is Mobitz 1 (Wenkebach).

Block 3

81. B – You know people make mistakes of all types after a few drinks.
82. A – Help her feel better. That’s the point of hospice.
83. D – With family members with both primary hyperparathyroidism and an “adrenal tumor” (let’s guess pheochromocytoma), we have two out of the MEN2A triad. The third is medullary thyroid cancer.
84. A – People with CVID are at increased risk of lymphoma. B-symptoms like fever, weight loss, and night sweats combined with lymphadenopathy are highly concerning.
85. E – I think the description here is a little odd, but a helpful reader suggested cigarette burns, which I think is probably correct. Alternatives could be a blistering burn secondary to intentional hot water submersion or really serious spanking, potentially with a welt-causing object. Either way, not an accidental/expected pattern. Whenever the story doesn’t make sense or there are any concerning physical exam findings, it is critical to work up for nonaccidental trauma.
86. E – History is clearly gallbladder (“biliary colic”). Now cholecystitis, so evaluate with ultrasound. Minimal lipase bumps can be seen with other GI and biliary issues, but also note that gallstones can also cause pancreatitis, so it’s certainly possible for her to also have that brewing. If you suspect gallbladder/biliary issues, always start with US.
87. B – Tracing shows a prolonged severe fetal bradycardia. This is bad. Causes include cord prolapse, placental abruption, uterine rupture, and uterine tachysystole. Umbilical cord prolapse is particularly common after AROM, where rapid descent of the fetal head compresses the umbilical cord, limiting blood flow as it’s squeezed inferiorly by the contracting uterus. Vertex station doesn’t actually matter as once previously thought, but a nondilated cervix (less than 6 cm) is a risk factor.
88. F – How many people with sats in the 80s have you seen not getting O2?
89. A – Ulcerative colitis is a risk factor for colon cancer. The skin lesions are a description of erythema nodosum.
90. A – Trauma and critical illness can cause acute insulin resistance.
91. A – Don’t be a dick.
92. C – Hyperaldosteronism = hypertension + hypokalemia. Adrenal adenomas are a common cause of primary hyperaldosteronism.
93. F – Necrotizing fasciitis = looks like bad cellulitis but then you add skin breakdown and necrotic goo.
94. D – The key to dealing with occupational exposures is safe practices. That means anything producing a particle or fume needs a respirator. You can’t fix the damage already done.
95. D – Spironolactone helps reduce ascites production and is the diuretic of choice for the initial treatment of portal hypertensive ascites.
96. C – Severe hypertriglyceridemia is an important risk factor for/cause of pancreatitis. Fibrates remain the drug of choice for severe HTG (TGs > 500 mg/dL).
97. B – Cirrhotic wanderer, completely disoriented. While potentially just intoxicated or suffering from hepatic encephalopathy, the question is again probably getting at Wernicke’s encephalopathy. Treatment is thiamine. It’s harmless, and that’s why lots of drunks get the banana bag.
98. B – Algorithmic standard approaches that reduce variability are the hallmark of high-quality care. Not everyone can receive heparin, but everyone needs to have a DVT prophylaxis plan so they don’t fall through the cracks.
99. A – Subtraction.
100. C – Stop. Wrong-sided surgery is a big no-no. Everyone on the team should feel empowered to stop a surgery or procedure if something in the preprocedural checklist is amiss.
101. E – PEEP is like cowbell. Okay not really but when gas exchange is insufficient with increased FiO2, PEEP will help open alveoli and increase the functional area available for ventilation.
102. A – TCA overdoses are potentially fatal due to the drugs’ cardiac effects. The most dangerous is that fast sodium channel blockage can lengthen the QRS and result in fatal ventricular arrhythmias.
103. C – The test of choice for AAA screening is ultrasound. Cheap and radiation-free.
104. A – Back pain, normocytic anemia, fatigue, and hypercalcemia. These are concerning for a hematopoietic process, particularly multiple myeloma. Serum protein electrophoresis will demonstrate the M-spike.
105. D – The decreasing and irregular periods coupled with high FSH suggest early menopause. Estrogen helps with bone strength. The lack predisposes to osteoporosis.
106. E – Increased bleeding with normal labs (or an isolated mildly prolonged PTT) is always a good picture for von Willebrand disease, the most common bleeding disorder. Yes, the PTT is slightly elevated (which can happen), but that’s also why they probably gave you boy and girl siblings to help you not pick hemophilia.
107. E – Colon cancer is a surgical disease.
108. B – Part of the DSM-V criteria for generalized anxiety disorder: “Excessive anxiety and worry (apprehensive expectation), occurring more days than not for at least 6 months, about a number of events or activities (such as work or school performance).”
109. A – Ascites with a neutrophil count higher than 250 is consistent with spontaneous bacterial peritonitis. Treatment of choice is a third-gen cephalosporin like cefotaxime or ceftriaxone.
110. E – AED-induced bone disease is a problem with long-term therapy. Carbamazepine and phenobarbital both induce CYP450 and can cause vitamin D deficiency.
111. A – Write it out. Abbreviations are like assumptions.
112. D – When it comes to development questions, always make sure before you pick something other than normal if offered. Tanner stages are available for review here.
113. D – Implantable birth control is much more effective than methods that require active effort.
114. F – Malignant pleural effusion. Cancer is full of protein.
115. E – Ah, ye old “inconsistent condoms” code phrase for STDs.
116. B – Externally normally developed female with a 46XY male karyotype, elevated testosterone, and no internal sex organs is consistent with complete androgen insensitivity syndrome. While somewhat controversial particularly with regards to timing, gonadecotmy is recommended to remove the undescended gonads to prevent cancer. In this case, she’s already gone through puberty. If gonadectomy is performed earlier in childhood, then puberty will need to be induced with HRT.
117. C – HCTZ (and other symporter and loop diuretics) can result in diuretic-induced hyperuricemia and cause or worsen gout.
118. D – This is the MSG symptom complex, sometimes historically and pejoratively called “Chinese Restaurant Syndrome.” While MSG gets a bad wrap, real MSG sensitivity is rare.
119. C – Don’t be a dick. But you don’t have to entirely give up either: she may come around after her crazy simmers for a while.
120. F – Sciatica.

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