Deck 1

Question 1

Common side effect of testosterone

Answer 1

Polycythemia is a common adverse effect of testosterone injections and anabolic steroids, and testosterone supplementation should be interrupted if the hematocrit level exceeds 54%.

hematocrit level at initiation, 3 to 6 months after testosterone initiation, and annually thereafter is recommended by Endocrine Society guidelines.

Question 2

Testosterone can exacerbate..

Answer 2

Testosterone supplementation can also exacerbate undiagnosed sleep apnea, and evaluation for an underlying sleep disorder should be performed in these patients with polycythemia.

Question 3

What is PV?

Answer 3

Polycythemia vera (PV) is a disorder of the myeloid and erythroid stem cells that causes erythropoietin-independent proliferation of erythrocytes and splenomegaly. PV should be considered in all patients with polycythemia; however, in this patient who is receiving testosterone supplementation, has an elevated erythropoietin level, and does not have splenomegaly, PV is unlikely. If PV is suspected, mutational analysis for JAK2 V617F should be performed.

Question 4

What is Capnocytophaga canimorsus?

Answer 4

C. canimorsus is a gram-negative bacillus that can cause overwhelming sepsis in patients with functional or anatomic asplenia who have experienced a dog bite or scratch. Because of its activity against pathogens associated with animal bite wounds, a 3- to 5-day course of amoxicillin-clavulanate is recommended for patients who are immunosuppressed (including patients with cirrhosis and asplenia); have wounds with associated edema, lymphatic or venous insufficiency, or crush injury; have wounds involving a joint or bone; have deep puncture wounds; or have moderate to severe injuries, especially when involving the face, genitalia, or hand. If a patient is allergic to penicillin, a combination of trimethoprim-sulfamethoxazole or a fluoroquinolone or doxycycline plus clindamycin or metronidazole can be used.

Question 5

Statin guidelines according to AHA

Answer 5

According to the 2018 AHA/ACC Guideline on the Management of Blood Cholesterol, groups for which a strong body of evidence supports statin initiation for the primary prevention of ASCVD are patients with an LDL cholesterol level of 190 mg/dL (4.92 mmol/L) or higher, patients aged 40 to 75 years with diabetes mellitus, and patients with a 10-year risk for ASCVD of 20% or higher. Other populations in whom statin therapy should be considered include patients with a 10-year risk for ASCVD of 7.5% to less than 20% accompanied by ASCVD risk-enhancing factors. In this patient with a 10-year risk for ASCVD of 3.4%, statin therapy would not be appropriate.

Question 6

Statin guidelines according to USPSTS

Answer 6

The U.S. Preventive Services Task Force recommends low- to moderate-intensity statin therapy in asymptomatic adults aged 40 to 75 years without ASCVD who have at least one ASCVD risk factor (dyslipidemia, diabetes mellitus, hypertension, or smoking) and a calculated 10-year ASCVD event risk of 10% or higher. In contrast, the U.S. Department of Veterans Affairs and U.S. Department of Defense cholesterol guideline recommends primary prevention with moderate-intensity statin therapy for patients with a 10-year ASCVD risk of 12% or more, an LDL cholesterol level of 190 mg/dL (4.92 mmol/L) or higher, or diabetes. Although this patient has hyperlipidemia, his 10-year ASCVD event risk is 3.4%, and neither low- nor moderate-intensity statin therapy is indicated.

Question 7

Normal lipid profile

Answer 7

Laboratory studies:

Total cholesterol: Normal: Less than 200 mg/dL
Borderline high: 200 to 239 mg/dL
High: At or above 240 mg/dL

LDL cholesterol:Optimal: Less than 100 mg/dL (This is the goal for people with diabetes or heart disease.)
Near optimal: 100 to 129 mg/dL
Borderline high: 130 to 159 mg/dL
High: 160 to 189 mg/dL
Very high: 190 mg/dL and higher

HDL cholesterol:Your HDL cholesterol levels should be above 40 mg/dL.
Sixty mg/dL or above is considered the level to protect you against heart disease.

Triglycerides:
Normal: Less than 150 mg/dL
Borderline high: 150 to 199 mg/dL
High: 200 to 499 mg/dL
Very high: Above 500 mg/dL

Question 8

Types of psoriasis

Answer 8

There are many different patterns of psoriasis including classic psoriasis vulgaris (erythematous patches with a thick, adherent scale), inverse psoriasis (red, thin plaques with variable amount of scale in the axillae, under the breasts or pannus, intergluteal cleft, and perineum), sebopsoriasis (red, thin plaques in the scalp, eyebrows, nasolabial folds, central chest, and pubic area), and guttate psoriasis (0.5- to 2-cm red plaques that erupt suddenly on the trunk often after a group A streptococcal infection). Psoriasis can also involve the nails presenting as pit-like indentations and “oil spots” often involving multiple nails.

Question 9

Inverse psoriasis

Answer 9

Inverse psoriasis is characterized by red, thin plaques with variable amounts of scale in the axillae, intergluteal cleft, and perineum, and under the breasts and pannus.
Inverse psoriasis can be difficult to diagnosis because it often lacks the classic silvery scale. It also resembles other common dermatologic conditions such as tinea, intertrigo, and allergic contact dermatitis.

Question 10

Opioid prescribing guidelines

Answer 10

The Centers for Disease Control and Prevention Guideline for Prescribing Opioids for Chronic Pain recommends that before starting and periodically during continuation of opioid therapy, clinicians should evaluate risk factors for opioid-related harms. Clinicians should incorporate into the management plan strategies to mitigate risk, including offering naloxone when factors that increase risk for opioid overdose (such as history of overdose, history of substance use disorder, higher opioid dosages [≥50 morphine milligram equivalents/day], or concurrent benzodiazepine use) are present. Other factors that strongly support the coprescribing of naloxone include the presence of COPD or obstructive sleep apnea. Similar interventions are indicated for patients not prescribed opioids but who are otherwise at high risk for overdose, such as those illicitly using opioids or drugs that may be contaminated with opioids (methamphetamine and cocaine), those with a history of opioid misuse who have been recently released from incarceration, and those receiving treatment for opioid use disorder. Other recommended risk-mitigation strategies include reviewing the patient’s history of controlled substance use with state prescription monitoring program data and urine drug testing before initiation of therapy and at least annually thereafter.

Question 11

When to start HD?

Answer 11

With careful clinical management, dialysis may be delayed until either the GFR drops below 7.0 mL/min/1.73 m2 or more traditional clinical indicators (such as uremic symptoms or metabolic abnormalities) for the initiation of dialysis are present.

Question 12

What is vismodegib?

Answer 12

Vismodegib is an oral medication that inhibits the hedgehog signaling pathway. It is reserved for locally advanced or metastatic basal cell carcinomas. There are significant side effects including dysgeusia, alopecia, and muscle cramps.

Question 13

What happens to thyroid binding globulin when testosterone supplements are started?

Answer 13

In patients receiving thyroxine replacement therapy, initiation of estrogen or raloxifene increases thyroxine-binding globulin levels whereas testosterone reduces thyroxine-binding globulin levels; in either situation a change in thyroxine dosage may be required.

Question 14

What happens with metabolically active free thyroxine when thyroxine binding globulin decreases? increases?
What can decease/increase thyroid binding globulin?

Answer 14

reduction in thyroxine-binding globulin, which consequently increases the proportion of metabolically active free thyroxine that is available.

Question 15

What is pyroglutamic acidosis?

Answer 15

Pyroglutamic acidosis occurs in patients receiving therapeutic doses of acetaminophen on a chronic basis in the setting of critical illness, poor nutrition, liver disease, chronic kidney disease, or a strict vegetarian diet; diagnosis can be confirmed by measuring urine levels of pyroglutamic acid.

In this context, acetaminophen leads to depletion of glutathione, altering the γ-glutamyl cycle to overproduce pyroglutamic acid (also known as 5-oxoproline).

Question 16

Diagnosing gastroparesis

Answer 16

The diagnosis of gastroparesis requires the presence of specific symptoms, absence of mechanical outlet obstruction, and objective evidence of delay in gastric emptying into the duodenum.

he three tests to objectively demonstrate delayed gastric emptying are gastric scintigraphy, wireless motility capsule, and the gastric emptying breath test. If scintigraphy is pursued, the 4-hour study is preferred over 90- or 120-minute studies due to increased diagnostic accuracy.

Question 17

Treat gastroparesis

Answer 17

Both metoclopramide and domperidone are effective in the treatment of gastroparesis. Metoclopramide is the only FDA-approved agent for the treatment of gastroparesis. Domperidone can be used under a special program administered by the FDA. The side effects of metoclopramide include dystonia, Parkinson-type movements, and tardive dyskinesia. Domperidone can prolong the QT interval on electrocardiography, potentially leading to cardiac arrhythmia. Before initiating treatment for gastroparesis, it is necessary to confirm the diagnosis.

Question 18

What is Ventricular free wall rupture?

Answer 18

a rare complication of myocardial infarction that produces sudden-onset chest pain or syncope with rapid progression to pulseless electrical activity.
Free wall rupture is more common in older adults, women, patients with anterior myocardial infarction, those receiving anti-inflammatory agents, and patients with a significant delay in receiving reperfusion therapy (>12 hours).

Question 19

Scleroderma renal crisis

Answer 19

Features of scleroderma renal crisis include hypertensive emergency, headache, microangiopathic hemolytic anemia, thrombocytopenia, elevated serum creatinine levels, and proteinuria; treatment involves ACE inhibitors, typically captopril.
Anti-RNA polymerase III antibodies serve as a marker for increased risk for scleroderma renal crisis as well as extensive skin disease. The use of ACE inhibitors has dropped the 1-year mortality of scleroderma renal crisis from 76% to 15%.

Question 20

What is erythrasma?

Answer 20

Erythrasma is a superficial infection with Corynebacterium minutissimum. Its growth is encouraged by a warm, moist environment, such as intertriginous areas. Erythrasma causes well-defined, pink-to-brown patches with fine scale, located in the axillae, groin, or inframammary regions. A unique feature of this infection is that it fluoresces a bright coral-red color when illuminated with a Wood lamp. The location, morphology, and color of this patient’s skin findings are not consistent with erythrasma.

Question 21

How does adrenal crisis present?

Answer 21

usually present with hypotension, hyponatremia, and hyperkalemia, in addition to gastrointestinal manifestations.

Question 22

How to treat thyroid storm?

Answer 22

Management includes treatment of any precipitant illness, supportive care, and thyrotoxicosis-directed therapy including β-adrenergic blockers (esmolol infusion), antithyroid drug therapy, intravenous glucocorticoids, and potassium iodide. Plasmapheresis and emergent thyroidectomy are utilized in patients who cannot be sufficiently managed with medical therapy alone.

Question 23

How to treat ameba liver abscess?

Answer 23

The mainstay of therapy for amebic liver abscesses is antibiotic therapy, such as metronidazole, plus a luminal agent, such as paromomycin, to eradicate the coexisting intestinal infection.

Question 24

What is adynamic bine disease?

Answer 24

Adynamic bone disease can occur in patients with chronic kidney disease or those on dialysis and is associated with fracture or bone pain; parathyroid hormone and alkaline phosphatase levels are typically normal.
High PTH and alkaline phosphatase would exclude adynamic bone disease; in this disorder, both are typically normal.

Question 25

Mobitz type 2 second-degree atrioventricular block is an uncommon but potentially life-threatening electrical complication of anterior myocardial infarction; temporary or permanent pacing is indicated in this setting.
It usually represents a block lower in the conduction system and suggests significant conduction disease, likely resulting from ischemia and necrosis of the septum (along which the His-Purkinje system is located). Because of the high risk for progression to complete heart block, prompt implantation of a temporary or permanent pacemaker is indicated.

Answer 25

When progressive PR prolongation is observed before a blocked beat, second-degree Mobitz type 1 (Wenckebach) block is present. When the PR interval is constant before nonconducted P waves, the second-degree block is termed Mobitz type 2 block.
Cessation of β-blocker therapy alone will not improve conduction in this patient, as the pathology of Mobitz type 2 block is beyond the AV node. In contrast, Mobitz type 1 second-degree AV block is frequently seen with acute inferior myocardial infarction and may be associated with periods of complete heart block. Observation and withholding of AV nodal blocking agents is appropriate in that context, as the need for permanent pacing is extremely low with inferior myocardial infarction.

Question 26

What is myoclonus?

Answer 26

Myoclonus consists of rapid, nonsuppressible, shock-like, jerky movements that can result from metabolic, endocrine, toxic, infectious, epileptic, autoimmune, and other causes. Posthypoxic myoclonus (Lance-Adams syndrome) occurs in patients with a history of hypoxic brain injury (suggested in this patient by his previous cardiopulmonary arrest) and is characterized by prominent action-induced myoclonus that impairs ambulation because of a combination of positive (rapid jerky movements) and negative (lapses in muscle tone) myoclonus. Other examples of negative myoclonus include hiccups and asterixis

Question 27

Alzheimer’s treatment

Answer 27

Both cholinesterase inhibitors (such as donepezil) and the N-methyl-D-aspartate receptor antagonist memantine are approved for treatment of moderate stages of Alzheimer disease.
Relative contraindications for cholinesterase inhibitor use include (but are not limited to) sick sinus syndrome, left bundle branch block, uncontrolled asthma, angle-closure glaucoma, and ulcer disease.

Question 28

metastatic Non small cell lung cancer treatment

Answer 28

Up until recently, the accepted front-line treatment for patients with metastatic non−small cell lung cancer was platinum-based chemotherapy in all patients except those found to have a driver mutation, in whom small molecule inhibitors, such as erlotinib, are indicated. However, pembrolizumab has recently been approved by the FDA for the initial treatment of metastatic non−small cell lung cancer positive for expression of programmed cell death ligand 1 (PD-L1). Pembrolizumab is a monoclonal antibody directed against PD-L1, and it blocks binding of this ligand to the programmed death receptor 1 receptor, preventing the cancer from silencing cellular immunity. This agent was found to improve overall survival compared to platinum-based chemotherapy in a phase III trial that enrolled 305 patients with advanced non-small cell lung cancer who had at least 50% tumor cell positivity for PD-L1. In this study, overall survival was 10.3 months with pembrolizumab compared to 6 months with platinum-based chemotherapy. Based on this data, it has now become standard practice to test all patients newly diagnosed with metastatic non−small cell lung cancer for PD-L1 expression.

Question 29

Secondary hypogonadism

Answer 29

low testosterone level and low serum luteinizing hormone (LH) and follicle-stimulating hormone (FSH) concentrations
MRI of the pituitary is typically performed to evaluate secondary hypogonadism in the absence of obvious reversible causes such as drugs.

Question 30

Hyperprolactinemia

Answer 30

leads to secondary hypogonadism through suppression of gonadotropin-releasing hormone synthesis and secretion. This patient is on no medications that might cause hyperprolactinemia. In the absence of a culprit drug, the most likely cause of his hyperprolactinemia is a lactotroph adenoma; therefore a pituitary MRI is indicated.

Question 31

dermatofibroma

Answer 31

benign firm brown or reddish papules about the size of a pencil eraser that most commonly occur on the lower extremities; they “dimple” when lateral pressure is applied to the lesion with the thumb and first finger.

Question 32

Heparin causes hyperkalemia

Answer 32

Hypoaldosteronism caused by heparin, inhibitors of the renin-angiotensin system, type 4 renal tubular acidosis, or primary adrenal disease can cause hyperkalemia. Both unfractionated and low-molecular-weight heparin use is associated with a decrease in aldosterone synthesis. This occurs more frequently in patients with chronic kidney disease or diabetes mellitus, or in those taking an ACE inhibitor or angiotensin receptor blocker.

Question 33

Hep B rx in pregnancy

Answer 33

Pregnant women who have hepatitis B virus DNA levels greater than 200,000 IU/mL at 24 to 28 weeks’ gestation should be treated with tenofovir to prevent vertical transmission during delivery.

Question 34

Diarrhea in lifeguard

Answer 34

The protozoan Cryptosporidium is the most common cause of swimming pool–related outbreaks of diarrhea; diagnosis is made by microscopic examination of the stool or by stool antigen testing.

Question 35

Treat a patient with severe acute respiratory distress syndrome using early prone positioning.

Answer 35

This patient should be ventilated in the prone position. In patients with acute respiratory distress syndrome (ARDS) low tidal volume ventilation (6-8 mL/kg ideal body weight) is optimal and is associated with significantly better outcomes than conventional, higher tidal volume ventilation (10-12 mL/kg).

Question 36

Anal cancer treatment

Answer 36

Anal cancer is often curable with combined chemotherapy and radiation, avoiding surgery.
Surgery for anal cancer is reserved as a salvage treatment for either local recurrence or incomplete response to chemotherapy plus radiation therapy, and is potentially curative. However, because definitive surgery must remove the anal sphincter, a placement of a permanent colostomy would be required.

Question 37

Manage a patient with a bicuspid aortic valve and enlarged aortic root with surveillance echocardiography.

Answer 37

Patients with a bicuspid aortic valve are prone to enlargement of the ascending aorta, and patients with both a bicuspid aortic valve and enlarged aortic dimensions are at higher risk for aortic dissection. Surveillance echocardiography should be performed in these patients to monitor aortic growth. Patients with a bicuspid aortic valve and a thoracic aortic aneurysm should undergo annual imaging if the aortic diameter has been stable and smaller than 4.5 cm. If the aortic diameter is 4.5 cm or larger or the rate of enlargement exceeds 0.5 cm/year, imaging should be performed every 6 months.

Question 38

Diagnose transitional cell (urothelial) cancer in a patient with Balkan endemic nephropathy.

Answer 38

The patient has Balkan endemic nephropathy (BEN), a slowly progressive tubulointerstitial disease that has been linked to aristolochic acid. Aristolochic acid is a nephrotoxic alkaloid from the plant Aristolochia clematitis. BEN has a high prevalence rate in southeastern Europe (Serbia, Bulgaria, Romania, Bosnia and Herzegovina, and Croatia) and is the cause of kidney disease in up to 70% of patients receiving dialysis in some of the most heavily affected regions. Aristolochic acid is also sometimes found as a component of herbal therapies used for weight loss. Characteristics of BEN include chronic kidney disease due to tubulointerstitial injury, tubular dysfunction (polyuria and decreased concentrating ability, glucosuria without hyperglycemia, and tubular proteinuria), and anemia. Ultrasound demonstrates small echogenic kidneys. BEN has a familial but not inherited pattern of distribution. It is thought to be caused by exposure to aristolochic acid, and, because it is mutagenic, it is strongly associated with the development of upper tract transitional cell (urothelial) cancers. Therefore, urologic evaluation is indicated.

Question 39

Evaluate for coronary artery disease in a patient with left bundle branch block on a baseline electrocardiogram.

Answer 39

In patients with left bundle branch block, the preferred diagnostic test for coronary artery disease is a vasodilator stress test because myocardial perfusion imaging with exercise or dobutamine stress may result in a false-positive perfusion defect in the basilar septum.

Question 40

Coronary artery calcium scoring

Answer 40

Coronary artery calcium scoring, which quantifies the amount of calcium in the walls of the coronary arteries, would document the presence of atherosclerotic disease in this symptomatic patient with risk factors, but it would not determine whether there is obstructive CAD. Although the absence of any coronary artery calcification has been shown to have a high specificity for the absence of obstructive CAD, trials evaluating coronary artery calcium scoring have typically focused on primary prevention in asymptomatic patients.

Question 41

Diagnose α-thalassemia trait.

Answer 41

Patients with α-thalassemia trait have inadequate production of two copies of the α gene on chromosome 16 (α−/α− or −−/αα). Such patients have a chronic microcytic anemia with hemoglobin levels of approximately 10 g/dL (100 g/L). Hemoglobin A levels, although reduced in quantity, are otherwise normal in these patients and will migrate in a normal pattern on electrophoresis. Furthermore, there is no increase in the minor hemoglobin components, hemoglobin A2 and hemoglobin F. It is possible to identify specific chromosomal abnormalities that establish the diagnosis of α-thalassemia, but physicians typically make a clinical diagnosis based on family history, complete blood count, peripheral blood smear, and hemoglobin electrophoresis and by ruling out other causes of microcytic anemia. Patients with thalassemia should receive supplemental folate but should not receive iron supplementation; they are not iron deficient and they have an increased ability to absorb iron, which can lead to iron overload. Genetic counseling may be indicated in reproductive planning.

Question 42

Yersinia Pestis

Answer 42

one of the biologic agents classified as an A-list bioterrorism pathogen because of its high potential lethality and ease of dissemination. Sputum Gram stain (and possibly blood smear) may identify gram-negative coccobacilli demonstrating the classic bipolar staining or “safety pin” shape shown. Although most pulmonary involvement occurs through secondary hematogenous spread to the lungs from a bubo or other source, primary pneumonic plague can occur after close contact with another person with plague pneumonia, after animal exposure, or as a result of intentional aerosol release for the purpose of terrorism, as in this case. Recommended first-line treatment is either streptomycin or gentamicin.

Question 43

Bacillus anthracis

Answer 43

a gram-positive, aerobic organism. It appears as a sporulating gram-positive rod on microscopic examination. Patients with inhalational anthrax present with low-grade fever, malaise, myalgia, and headache accompanied by cough, dyspnea, and chest pain. A chest radiograph showing mediastinal widening from hemorrhagic lymphadenitis is characteristic. Ciprofloxacin, levofloxacin, moxifloxacin, or doxycycline should be provided as soon as possible after any actual or suspected case of anthrax that raises concern for a bioterrorism attack.

Question 44

Target BP

Answer 44

Based on evidence that the greatest absolute benefit of antihypertensive therapy is seen in patients with the highest blood pressure and cardiovascular risk, the American College of Physicians and American Academy of Family Physicians recommend that antihypertensive drugs be initiated in patients ≥60 years old if blood pressure is >150/90 mm Hg, with a goal of reducing systolic blood pressure to <150 mm Hg; the American College of Cardiology/American Heart Association recommends a systolic blood pressure target of <130 mm Hg in patients ≥65 years old.

Question 45

REstrrictive cardiomyopathy

Answer 45

Restrictive cardiomyopathy is distinguished from constrictive pericarditis by an elevated B-type natriuretic peptide level and concordant rise and fall of left and right systolic pressures with respiration.

Question 46

cardiac syndrome X

Answer 46

Cardiac syndrome X is a frequent cause of chest pain syndromes in women, and patients often present without traditional risk factors for coronary artery disease. The chest pain is often indistinguishable from classic exertional angina, and stress testing results are frequently abnormal. Many hypotheses have been proposed to explain the pathogenesis of cardiac syndrome X, with one of the most accepted centering on microvascular dysfunction as the cause. Although vasodilators should be tried, symptoms can be difficult to treat.

Question 47

Diagnose light chain cast nephropathy

Answer 47

In multiple myeloma, acute kidney injury from light chain cast nephropathy is the most common type of kidney disease. Cast nephropathy is characterized by intratubular obstruction with light chain casts that can result in acute tubular injury. A clinical clue to the diagnosis is the presence of an elevated urine protein-creatinine ratio, with minimal proteinuria detected by dipstick urinalysis (dipstick urinalysis detects albumin but not light chains). Other supporting findings are the presence of anemia and hypercalcemia (when calcium measurement is corrected for albumin).
discrepancy in proteinuria between urinalysis and urine protein-creatinine ratio.

Question 48

hepatopulmonary syndrome

Answer 48

Hepatopulmonary syndrome is a complication of cirrhosis caused by dilation of the pulmonary vasculature in the setting of advanced liver disease and portal hypertension. A high alveolar-arterial oxygen gradient results from functional shunting. Patients with hepatopulmonary syndrome usually have a preexisting diagnosis of liver disease and present with shortness of breath. Dilation of pulmonary vasculature occurs at the base of the lungs, so hypoxemia is most noted when patients are upright or sitting, when shunting is maximal. Classic features are platypnea (worsening shortness of breath in the upright position) and orthodeoxia (worsening arterial oxygen saturation in the upright position). Pulse oximetry is often used to screen for changes in the arterial oxygen saturation level with changes of position. The diagnosis is made by demonstrating an arterial oxygen tension less than 80 mm Hg (10.7 kPa) breathing ambient air, or an alveolar-arterial gradient of 15 mm Hg (2 kPa) or greater, along with evidence of intrapulmonary shunting on echocardiography with agitated saline or macroaggregated albumin study. The detection of intrapulmonary shunting of blood is best confirmed by echocardiography with agitated saline (also known as a bubble study), during which bubbles are identified in the left side of the heart after 5 beats, demonstrating that the shunting of blood is not intracardiac.

Question 49

Amyloidosis

Answer 49

Amyloid light chain amyloidosis is the most common type of amyloidosis; it is a plasma cell dyscrasia-related disease characterized by end-organ damage secondary to tissue deposition of monoclonal free λ or κ light-chain fibrils. Clinical symptoms and manifestations vary and are dictated by the tissue tropism of the amyloidogenic light chain. If amyloid deposits are identified on tissue biopsy, other types of amyloidosis should be excluded by typing, which can be done by κ/λ light-chain immunohistochemistry. Major clinical manifestations include proteinuria with worsening kidney function, restrictive cardiomyopathy, and hepatomegaly. Neurologic findings include a symmetric, distal sensorimotor neuropathy, carpal tunnel syndrome, and autonomic neuropathy with orthostatic hypotension. Skin manifestations are present in 30% to 40% of patients and include generalized waxy appearance, ecchymoses with minor pressure (“pinch purpura”), ecchymoses around the eyes (“raccoon eyes”), yellow waxy papules and plaques especially in a periorbital location, dystrophic nails, and macroglossia. Bleeding caused by acquired factor X deficiency may also occur.

Question 50

hypernatremia caused by central diabetes insipidus.

Answer 50

central nervous system sarcoidosis and central diabetes insipidus (DI). Nearly half of hypothalamic-pituitary sarcoidosis cases occur in the course of previously treated sarcoidosis. Central DI results from inadequate release of ADH from the posterior pituitary gland. In the presence of ADH, aquaporin water channels are inserted in the collecting tubules and allow water to be reabsorbed. In the absence of ADH, excessive water is excreted by the kidneys. Frank hypernatremia is unusual because patients develop extreme thirst and polydipsia, and with free access to water, can maintain serum sodium in the high normal range. When patients do not drink enough to replace the water lost in the urine, due to poor or absent thirst drive or lack of free access to water, they develop hypernatremia. DI is diagnosed with simultaneous laboratory evidence of inability to concentrate urine (urine osmolality <300 mOsm/kg H2O) in the face of elevated serum sodium and osmolality. If necessary, a water deprivation test can confirm the diagnosis. A response to exogenous ADH would support a diagnosis of central DI, whereas a lack of response is seen in nephrogenic DI.

Question 51

Tolvaptan

Answer 51

Tolvaptan is a vasopressin receptor antagonist sometimes used for the syndrome of inappropriate antidiuretic hormone secretion, which is characterized by normal volume status, hyponatremia, and inappropriately elevated urine osmolality