USMLE USMLE-STEP-2 Online Practice Questions and Exam Preparation

USMLE USMLE-STEP-2 Online Questions & Answers

• Question 201:

  A 44-year-old man presents with fears that his mathematical abilities have been slowly sucked out of his brain for the last 4 years. He believes an "alien force disguised as a human being" is responsible. To avoid contacting this being, he has isolated himself in a room in a boarding house. His wife divorced him and left with their children. After 10 years teaching math at a local high school, he resigned about 3 years ago. He supports himself by "collecting cans." His affect is blunted. His appearance is disheveled, unshaven, and unwashed.

  Which of the following is the most likely diagnosis?

  A. paranoid schizophrenia
  B. alcohol abuse and dependence
  C. major depression with psychotic features
  D. Alzheimer's disease
  E. Huntington's disease
  A. paranoid schizophrenia

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  Explanation

  The preoccupation with a rather welldeveloped delusional system and later age at onset suggest paranoid schizophrenia. A case can be made for undifferentiated schizophrenia because of the apparent disorganization in personal habits and the flattening of affect. There is no history of alcohol abuse and dependence to support the diagnosis. The long period of symptoms, bizarreness of paranoid delusion, and decline in functioning are more characteristic of schizophrenia. The time course of a major depression is much shorter. Usually, in major depression there is not the profound decline in functioning. No symptoms of memory impairment or loss of cognitive functioning have occurred that would suggest Alzheimer or Huntington dementias. In addition, in Huntington dementia, one would expect a prominent movement disorder as seen in subcortical dementia.

• Question 202:

  A 42-year-old woman is noted to have a multinodular goiter on examination. She has no symptoms and is clinically euthyroid. Which of the following statements about Hashimoto's thyroiditis is true?

  A. The condition is associated with prior radioactive exposure.
  B. Patients diagnosed with this disorder have an increased incidence of thyroid cancer.
  C. Corticosteroids are helpful in controlling the progression of the disease.
  D. Antinuclear antibodies are pathognomonic for this disease.
  E. Hashimoto's thyroiditis is an autoimmune disease.
  E. Hashimoto's thyroiditis is an autoimmune disease.

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  Explanation

  Hashimoto's thyroiditis, an autoimmune condition, is the leading cause of multinodular goiter in the United States. Although not unique to this condition, antimicrosomal antibodies are found in 7095% of patients. Antinuclear antibodies are associated with SLE. Although an autoimmune process, steroids are of no benefit in this condition. One-third of patients experience progressive loss of glandular function, and eventually become hypothyroid, but there is no increased incidence of thyroid cancer

• Question 203:

  For each of the diseases listed, select the arthropod vector responsible for its transmission.

  Yellow fever

  A. aegypti
  B. Anopheles species
  C. Pediculus humanus corporis
  D. Dermacentor andersoni
  E. Sarcoptes scabiei
  A. aegypti

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  Explanation

  Epidemic typhus (classical typhus fever, or louse-borne typhus) has disappeared from most areas of the world but might reappear in conditions of famine, war, or other disasters. There are small areas where it is endemic. The responsible organism, a rickettsia, is conveyed from case to case by the human body louse, P. humanus corporis. Malaria, in its various forms (Plasmodium falciparum, Plasmodium vivax, Plasmodium ovale, and Plasmodium malariae), is spread from human to human by females of the various Anopheles group of mosquitoes. Dengue fever has a worldwide distribution in tropical and subtropical areas. In addition to producing the classical fever with severe myalgia (breakbone fever), it can also cause a hemorrhagic fever. The causative agent, a group B arbovirus with four distinct serogroups, is virus- conveyed from case to case by the A aegypti mosquito. Colorado tick fever occurs mainly in mountainous areas of the United States within the range of its vector, D. andersoni. The highest incidence is in May and June. Several hundred cases are recorded annually, but it is likely that the actual incidence is much higher. Avoidance of tick bites is the principal control measure. Yellow fever, the prototypical viral hemorrhagic fever, is African in origin but has spread to and remains endemic in equatorial regions of Central and South America. The vector, A. aegypti, has also spread worldwide, but surprisingly, cases have not been reported in India and Southeast Asia. The illness varies in severity from a mild, nonspecific fever to a more severe condition with hemorrhagic, hepatic, and renal manifestations.

• Question 204:

  Identify the most likely diagnosis with the case descriptions below.

  A 40-year-old woman is brought to the emergency department after she had frantically called the paramedics because she thought she would die. She was experiencing sharp chest pain, shortness of breath, racing heartbeat, and cold, sweaty chills. Cardiac assessment proved negative for myocardial ischemia.

  A. body dysmorphic disorder
  B. conversion disorder
  C. factitious disorder
  D. hypochondriasis
  E. malingering
  F. pain disorder
  G. panic disorder
  H. somatization disorder
  G. panic disorder

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  Explanation

  Complaints involving both psychological and medical conditions are difficult to diagnose and treat. At times, medically identifiable causes are present, but the psychological factors contributing to the discomfort complicate the diagnosis and treatment and lead to frustration in both physician and patient. At other times, no identifiable cause for pain or other physical symptoms can be found; nevertheless, the patient still has the symptoms. Questions arise:

  Is the patient lying? Is there some deep psychological problem? Could there be a medical disorder in the early stages of development that gives rise to physical symptoms but no clear physical signs to make the diagnosis? One group of psychiatric disorders addresses some of these issues--the somatoform disorders. Somatization disorder is an axis I psychiatric disorder where a patient complains of multiple somatic complaints involving multiple organ systems, but which cannot be explained by physical and/ or laboratory findings. Conversion disorder is another axis I disorder where there is a disturbance of bodily function that does not conform to anatomic or neurologic concepts, and it is due to psychological factors. Body dysmorphic disorder is a pervasive subjective feeling/belief that some aspect of the patient's appearance is ugly or deformed.

  Hypochondriasis is a persistent belief in the presence of one or two serious physical diseases despite medical assurance that one does not have the disease/illness. Pain disorder (somatoform pain disorder) is a disorder with the presence of severe, distressing and persistent pain which cannot be explained adequately by evidence of a physiologic process or physical disorder. Panic disorder is a kind of anxiety disorder. Discrete periods of extreme sympathetic nervous system symptoms occur, including tachycardia, sweating, shortness of breath, and others, during which time a person experiences extreme fear. Malingering is the deliberate manufacture of false or exaggerated symptoms for financial gain or to avoid an unpleasant situation such as jail time or military duty. In a factitious disorder, there is the deliberate production of signs and symptoms of illness in order to assume the sick role.

• Question 205:

  Select the ONE best lettered option that is most closely associated with the question below.

  A 45-year-old female with pain and visible swelling in her metacarpal-phalangeal joints bilaterally. Her distal interphalangeal joints (DIPs) appear normal.

  A. rheumatoid arthritis
  B. SLE
  C. Wegener's granulomatosus
  D. polyarteritis nodosa
  E. Goodpasture syndrome
  F. fibromyalgia
  G. osteoarthritis (OA)
  H. giant cell arteritis
  I. sarcoidosis
  A. rheumatoid arthritis

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  Explanation

  Rheumatoid arthritis affects approximately 0.8% of the population. Women are affected three times more often than men. Synovial inflammation causes tenderness, swelling, and limitation of motion. Most often the arthritis is symmetric and characteristically involves joints such as the wrist and the proximal interphalangeal and metacarpophalangeal joints.

• Question 206:

  For each antihypertensive agent listed below, select the set of undesirable side effects with which it is most commonly associated with hydralazine

  A. cough, hyperkalemia, angioedema
  B. positive Coombs test, hemolytic anemia, hepatitis
  C. hypokalemia, hyperuricemia, hyperglycemia
  D. peripheral edema, flushing, and constipation
  E. increased angina, tachycardia, systemic lupus erythematosus (SLE)
  E. increased angina, tachycardia, systemic lupus erythematosus (SLE)

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  Explanation

  All of the drugs used to treat hypertension can cause adverse reactions, ranging from trivial to life threatening. Thiazide diuretics are associated with hypokalemia, causing arrhythmias; hyperuricemia causing gout; and hyperglycemia due to insulin resistance. The vasodilator hydralazine can cause tachycardia with increased angina and a lupuslike syndrome. As many as 10% of patients on angiotensin- converting enzyme (ACE) inhibitors develop an annoying dry cough. Because they block aldosterone, they can lead to hyperkalemia. ACE inhibitors cause 1025% of all cases of angioedema. Peripheral edema is the most commonly reported side effect of calcium channel blockers, especially amlodipine and nifedipine. Constipation, flushing, and dizziness are also frequently reported. Coombs'-positive hemolytic anemia and hepatitis are idiosyncratic reactions to the central adrenergic-stimulant methyldopa.

• Question 207:

  Repeated thunderstorms have resulted in overflow of municipal wastewater treatment plants by floodwaters. Volunteer sandbaggers downstream from the plants developed health concerns when the overflow became evident. As a public health officer you are asked to evaluate the situation. Which of the following is your most important recommendation to workers in order to prevent illness from exposure to the contaminated water?

  A. Do careful hand washing before meals and cigarette smoke breaks.
  B. Boil all water that is to be used for drinking or cooking.
  C. Offer hepatitis A vaccinations to al work crews prior to the next disaster.
  D. Start prophylaxis with a broad-spectrum antibiotic for all workers who do not have a contraindication.
  E. Offer oral polio vaccine to all eligible workers.
  A. Do careful hand washing before meals and cigarette smoke breaks.

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  Explanation

  Public health sanitation measures in emergency conditions should reduce fecal contamination of food and water supplies. Communicable disease such as typhoid fever, cholera, bacillary and amoebic dysentery, hepatitis, polio, schistosomiasis, various helminthes infestations, and viral gastroenteritis can be transmitted through contact with human feces. Avoiding putting fecal material in the mouth is key to avoiding infection.

• Question 208:

  A 4-year-old girl presents to the emergency department with fever and a petechial rash. A sepsis workup is performed, and IV antibiotics are administered. Gram-negative diplococci are identified in the CSF. Which of the following is true of this condition?

  A. Antibiotic prophylaxis of fellow daycare attendees is not necessary.
  B. The most common neurologic residual is seizures.
  C. The presence of meningitis decreases the survival rate.
  D. Shock is the usual cause of death.
  E. Vancomycin administered intravenously is the treatment of choice.
  D. Shock is the usual cause of death.

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  Explanation

  Meningococcemia is a fulminant systemic rapidly progressing infection that results in shock and is followed by death in 20% of afflicted children. The presence of meningitis has been shown to increase the survival rate to approximately 95%. Sensorineural deafness is the most common residual following bacterial meningitis. Penicillin, ampicillin, or a third-generation cephalosporin would be an appropriate antibiotic to choose for treatment. Vancomycin's spectrum of activity is limited to gram-positive organisms.

• Question 209:

  You see a young mother whose child is in need of medical care. She has an income below the federal poverty level. She is eligible to receive cash payments under the Supplemental Security Income Program (SSI). As she has no health insurance, you ask a social worker to help her enroll in a program funded with state and federal tax dollars, which provides complete medical care for her child. You ask that she be enrolled in which of the following programs?

  A. Medicaid
  B. Medicare
  C. Blue Cross/Blue Shield
  D. The Robert Wood Johnson Foundation
  E. Women, Infants, and Children program (WIC)
  A. Medicaid

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  Explanation

  Medicaid and Medicare began under federal legislation in 1966. Medicaid is a state-run program funded with federal and state tax dollars. It was established to provide medical services to the poor, with special consideration to pregnant women and small children. Although eligibility varies greatly from state to state, persons who receive SSI welfare payments are categorically eligible. Medicare is a federal program, completely financed and run by the federal government. Its purpose is to provide medical care to citizens over 65. Blue Cross/Blue Shield is a private insurance that must be purchased; the Robert Wood Johnson Foundation is a large foundation that provides grants; and the WIC program is a food supplement program for needy mothers and children.

• Question 210:

  A 10-month-old infant presents to the emergency department with a 24-hour history of low-grade fever and anorexia. The parents report several episodes in which the child has been suddenly inconsolable and crying, followed by periods of lethargy. He has had nonbilious vomiting and several loose stools. On examination, the infant is pale and mildly dehydrated. His abdomen is soft and nondistended, with fullness to palpation in the right upper quadrant. The child passed another stool in the emergency department

  

  Which of the following is the most likely diagnosis?

  A. gastroenteritis
  B. intussusception
  C. midgut volvulus
  D. Meckel's diverticulum
  E. juvenile rectal polyp
  B. intussusception

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  Explanation

  Intussusception most commonly occurs between 2 months and 2 years of age, often associated with a prodromal viral illness. Children will present with intermittent episodes of abdominal colic, secondary to peristaltic waves of the ileum against the partially obstructing ileocolic lesion. Reflex nonbilious vomiting is secondary to bowel distention and partial obstruction. There may be a palpable, right-sided, "sausageshaped" mass, but in many patients, the abdominal examination is entirely normal. The classic "currant jelly" stool is a late sign and is a result of ischemia and mucosal sloughing of the lead point. After the child has received IV fluid resuscitation, the management is hydrostatic reduction, either by contrast enema or air enema. Intussusception may occur during the clinical course of viral gastroenteritis. Bloody stools are more commonly associated with bacterial gastrointestinal infections, with characteristically loose, mucousy stools, and blood mixed with fecal material. Diagnosis is aided by obtaining stool cultures. A midgut volvulus can be associated with passage of a "currant jelly" stool secondary to small-bowel ischemia. However, these children usually present with bilious vomiting. Diagnosis may be confirmed with a UGI contrast study. Rectal bleeding from a Meckel's diverticulum is typically painless, without other associated gastrointestinal symptoms. Technetium scan is useful for diagnosis. Bleeding from a juvenile rectal polyp is usually small in amount and often occurs during normal stool passage. The children are clinically well, without other gastrointestinal symptoms. These polyps may be seen on proctoscopy.