NBME Medicine Form 5 - Answers & Explanations

Updated: Mar 6

Editor: Jordan Abrams


1) Valvular insufficiency of deep veins

● Mild edema due to incompetent valves + varicose veins due to saphenous vein reflux + area of hyperpigmentation (stasis dermatitis) over left ankle


2) Not eating mahimahi

● Histamine toxicity (scombroid poisoning) symptoms resembling anaphylaxis: flushing, headache and light-headedness (may also see urticaria, itching)

● Symptoms generally present within 10 minutes of eating dark-meat fish (eg, mahimahi)


3) Antihypertensive therapy

● HTN is greatest risk factor for both ischemic and hemorrhagic stroke (~4x the risk of a CVA compared to a normotensive individual)

● HTN → ↑ shearing forces on vascular endothelium → exacerbated atherosclerosis


4) Toxic adenoma of thyroid gland

● Toxic thyroid adenoma (hyper-functioning thyroid nodule) → hyperthyroidism sxs (eg, weight loss, palpitations, heat intolerance, fatigue, tachycardia, etc.)

● Labs: ↓ TSH, ↑ free T3 & T4, ↑ radioactive iodine (RAI) uptake in a single nodule

● DDx: ○ Subacute (de Quervain) thyroiditis would have a tender/painful goiter

○ Graves disease would show ↑ RAI uptake in diffuse pattern

○ Toxic multinodular goiter would ↑ RAI uptake in multiple nodules


5) Penicillin

• Painless chancroid on glans of penis is characteristic of Syphillis


6) Pancreatic adenocarcinoma

● Pancreatic tumor can commonly compress and dilate pancreatic duct and common bile duct (double duct sign) → ↑ ALP and ↑ Direct Bilirubin

● Unexplained migratory thrombophlebitis can also commonly be seen in Pancreatic Adenocarcinoma


7) B-Thalassemia trait

● ↓ synthesis of Beta chains → ↑ HbA2 (2 alpha chains, 2 delta chains)

● Beta Thalassemia trait is most often asymptomatic in presentation


8) Tuberculosis

● Common Tuberculosis symptoms include fever, chills, hemoptysis

● Reactivation Tuberculosis preferentially affects the apices of the lung


9) Catheterization of bladder

● Bladder obstruction/distention commonly presents with dysuria and a tender suprapubic mass

● Treatment → Catheterization to relieve obstruction and void distended bladder


10) Complete Heart block

● P waves and QRS complexes are not associated with one another

● R-R interval is also regular


11) Hypomagnesemia

● Severely hypomagnesemia → suppressed PTH → hypocalcemia

● Alcoholism may lead to hypomagnesemia


12) Add simvastatin to her current regimen

● Age 40-75 with Diabetes Mellitus → Statins are indicated

● Statins blocks rate limiting enzyme (HMG-CoA Reductase) in cholesterol production


13) Hematogenous dissemination of distant infection

● Pott disease (extra-pulmonary tuberculosis)

● hematogenous seeding of a distant infectious focus → infection of the vertebral bone → contiguous spread to the intervertebral discs and adjacent vertebrae


14) Adequate control of blood pressure

● HTN → left ventricular hypertrophy (LVH) and ↓ ejection fraction (EF)

● Blood pressure control can prevent further permanent damage to heart


15) Tracheomalacia

● Weakening of supporting tracheal cartilage → collapse of trachea upon expiration

● Long term intubation → tracheal weakening and structural damage of tracheal cartilage


16) Cor Pulmonale

● Impaired function of the right ventricle (RV) due to pulmonary hypertension (pulmonary systolic pressure >25 mmHg)

● Symptoms: dyspnea, fatigue, exertional angina

● Signs: JVD, ascites, hepatomegaly, and pitting edema


17) 0.9% Saline

● Administration of IV Isotonic Saline prior to CT can generally help to restore renal perfusion and prevent renal damage via IV contrast (contrast nephropathy)


18) Nephrogenic diabetes insipidus

● Hypercalcemia can induce nephron damage → diabetes insipidus (DI) → polyuria, polydipsia, dehydration and volume depletion

● Nephrogenic DI → Failure of the kidney to respond to ADH


19) Crohn's disease

● Crohn’s Disease is characterized by chronic abdominal pain, diarrhea, weight loss and evidence of inflammation


20) Hot tub use

● Hypersensitivity pneumonitis caused by Mycobacterium avium complex (hot tub lung)



21) Add fluticasone

● Mild persistent asthma → add ICS (inhaled corticosteroid) to SABA (short acting beta agonist [eg, albuterol PRN])


22) Lymphangitis

● Lymphangitis → Inflammation of lymphatic channels that occurs as a result of infection or trauma at a site distal to the channel

● It will generally follow a pattern of red track marks along lymphatics

● Infection → ↑White Blood Cell (WBC), Left Shift, fever


23) Serum anti mitochondrial antibody assays

● Primary biliary cholangitis (PBC) characteristically presents with ↑ anti-mitochondrial antibodies and cholestatic pattern of liver injury (↑↑ ALP, ↑ AST and ALT) in middle-aged women

● Pathogenesis: autoimmune destruction of small bile ducts → intrahepatic cholestasis

● Presents insidiously with fatigue and pruritus


24) CT scan of abdomen

● ↑↑ Dehydroepiandrosterone (DHEAS) and no suppression of cortisol after overnight dexamethasone → Adrenal origin

● CT scan of abdomen to visualize Adrenal tumor secreting DHEAS


25) Alendronate

● Long term treatment of osteoporosis → bisphosphonates, calcium and vitamin D supplementation

● Bisphosphonates inhibit osteoclast activity


26) Nitrofurantoin therapy

● Treatment of uncomplicated cystitis → nitrofurantoin, trimethoprim-sulfamethoxazole (TMP-SMX), or Fosfomycin


27) Acute respiratory distress syndrome

● Acute Respiratory Distress Syndrome (ARDS) → Non - Cardiogenic lung injury → Inflammation → fluid leakage into alveoli

● Bilateral lung opacities are generally seen on Chest X- Ray

● Common risk factor for ARDS → trauma (i.e. Intubation)

● ARDS can present with hypoxemia with a PaO2/FiO2 ratio < 300mmHG


28) Pulmonary contusion

● Pulmonary contusions typically present <24 hours after blunt thoracic trauma

● Injury to the underlying lung → alveolar hemorrhage → tachypnea, tachycardia, hypoxia

● Chest X - Ray can show patchy, alveolar infiltrates not restricted by anatomical borders


29) Small cell carcinoma of the lung

● Smoking is a strong risk factor for Small Cell Carcinoma (SCC)

● SCC paraneoplastic syndromes → Cushing syndrome (↑ACTH → Skin hyperpigmentation), SIADH, Lambert-Eaton syndrome


30) Necrotizing otitis externa

● Risk factors for Necrotizing otitis externa → Age > 60, Diabetes Mellitus, Aural irrigation

● Clinical manifestations → severe ear pain, elevated erythrocyte sedimentation rate (ESR), granulation tissue in external auditory canal


31) Decreased absorption due to decreased serum 1,25- dihydroxycholecalciferol concentration

● 25 Hydroxycholecalciferol is converted to 1, 25 dihydroxycholecalciferol (active vitamin D) in the kidney via 1-alpha hydroxylase

● Renal Failure → inability to convert 25 Hydroxycholecalciferol to active vitamin D → ↓renal calcium reabsorption


32) Uremia

● Friction rub and substernal chest pain is a common clinical finding in pericarditis

● Uremia in the setting of acute or chronic renal failure can lead to pericarditis

● Blood Urea Nitrogen (BUN) levels > 60mg/dL → inflammation of the visceral and parietal layers of the pericardium


33) IgA nephropathy

● IgA nephropathy usually presents within 5 days of an upper respiratory tract infection (URTI) as recurrent gross hematuria

● More commonly seen in men ages 20-30


34) Quantitative serum immunoglobulin testing

● Common variable immunodeficiency (CVID) commonly presents with recurrent respiratory (sinusitis, otitis, pneumonia) and GI infections (Salmonella, Campylobacter)

● CVID → impaired B cell differentiation and hypogammaglobulinemia → ↓↓IgG ↓IgA/IgM seen on quantitative serum immunoglobulin testing


35) Acetaminophen

● Febrile non-hemolytic transfusion reaction is the most common adverse reaction that occurs within 1-6 hours of a transfusion

● Patients usually develop fever, chills and malaise without hemolysis

● Most febrile reactions are treated with acetaminophen


36) Heat stroke

● A common risk factor for non exertional heat stroke is advanced age and inability to obtain adequate fluids and/or being capable of leaving hot & humid weather

● Heat Stroke → core temperature above 40 degrees celsius (104 F) and CNS dysfunction, additional organ/tissue damage


37) Increased creatine kinase activity

● Rhabdomyolysis → skeletal muscle lysis/necrosis which can common arise from prolonged immobilization

● Serum studies can show ↑↑CK (>1,000 U/L), ↑K ↑PO4 ↓Calcium ↑AST>ALT


38) Immediate groin exploration

● Examine for incarcerated inguinal hernia


39) Spinal cord

● Multiple sclerosis (MS) should be suspected in young women with neurological defects disseminated in space and time

● A common manifestation of MS is transverse myelitis → motor and sensory loss below the level of the lesion with bowel and bladder dysfunction. Patients can initially have flaccid paralysis (spinal shock), followed by spastic paralysis with hyperreflexia


40) MR angiography of the renal arteries

● Renovascular Disease such as Renal Artery Stenosis (RAS) can present clinically with resistant HTN, malignant HTN, onset of severe HTN (>180/120) after age 55

● Lab results can also point to an unexplained rise in creatinine (>30%) after starting ACE-Inhibitors

● Diagnosis can be confirmed by MR angiography of the renal arteries



41) Renal tubular acidosis

● Renal Tubular Acidosis (RTA) can cause a normal anion gap metabolic acidosis

● This patient with an ↑ urine pH likely has RTA type I due to their rheumatoid arthritis (RA)

○ Type IV has ↓ urine pH and can be caused by ACEi


42) Surgical excision

● Melanoma → excise the malignant tissue


43) Follow the advance directive

● Advance directive supersedes next of kin


44) HIV infection with candidal esophagitis

● Acute HIV infection typically presents 2-4 weeks after exposure and can commonly present with mononucleosis-like syndrome (fever, lymphadenopathy, sore throat, arthralgias)

● Candidal Esophagitis is common in HIV patients and will typically manifest as dysphagia/odynophagia + white plaques in buccal mucosa


45) Glucocorticoid therapy

● Sarcoidosis can commonly be seen in African Americans and can present with cough dyspnea and chest pain as well as hypercalcemia and bilateral hilar adenopathy and/or pulmonary reticular infiltrates

● Glucocorticoid therapy is the1st line treatment for symptomatic sarcoidosis


46) Oral acyclovir

● Herpetic whitlow finger → oral acyclovir is 1st line treatment


47) Obesity

● Too much stress on joints and bone, due to obesity, is generally the strongest predisposing factor for Osteoarthritis (OA) in the future


48) Exposure to nickel

● Nickel exposure is a common cause of contact dermatitis


49) Ruptured congenital aneurysm

● Subarachnoid hemorrhage commonly presents with a severe headache at onset of neurological symptoms (“Worst headache of my life”)

● Most commonly due to ruptured aneurysm


50) Phlebotomy

● Polycythemia Vera (PV) is a clonal myeloproliferative disorder characterized by erythrocytosis → ↑ Blood viscosity → Hypertension, Erythromelalgia (burning/cyanosis in hands and feet), transient visual disturbances, aquagenic pruritus

● Lab values generally show ↑ Hemoglobin ↑ Leukocyte count ↑ Platelet count ↓EPO levels

● First line treatment for PV symptoms → Phlebotomy




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