Answer Unit A

1) the correct answer is
D. The immediate step is to screen the family for TB exposure. The most effective manner in which to accomplish this is by placing PPDs on all members and working up those with a positive test. The white cell count may be elevated for a variety of reasons and would not necessarily help in diagnosis or management (choice A).

Sputum cultures will take 6 months to grow and may be too cumbersome to obtain (choice B).

Chest CT scans may show the tuberculosis lesion but a more effective method would be to place the PPD and perhaps then scan those with a positive test (choice C).

A bronchoscopy would be too invasive an option at this point (choice E)

2) The correct answer is
C. This patient has the classic presentation of a patient with acute gouty arthritis with the sudden onset of severe pain (typically in the middle of the night), swelling, erythema and warmth of a single joint. Low-grade fever and leukocytosis may be seen. It is more common in men and it is associated with hyperuricemia, usually due to decreased renal excretion of uric acid. Common causes are thiazides and alcohol. Diagnosis is made by examination of joint fluid under polarizing light. Negatively birefringent, needle-shaped crystals within polymorphonuclear leukocytes, hyperuricemia, and acute monoarticular arthritis make the definitive diagnosis of gout. Indomethacin or colchicine is the treatment during an acute attack. Allopurinol, probenecid, and sulfinpyrazone are used for prophylaxis against further attacks.

Allopurinol (choice A) is a xanthine oxidase inhibitor that is used as an antihyperuricemic agent by individuals with recurrent gouty attacks. Common side effects include rash, headache, and gastrointestinal upset.

Ceftriaxone (choice B) is the treatment of acute gonococcal arthritis. It has no role in the treatment of gout.

Probenecid (choice D) is a uricosuric agent that increases the rate of urate excretion. It is used to prevent gouty attacks. It may precipitate nephrolithiasis.

Sulfinpyrazone (choice E) is another uricosuric agent that increases urate excretion. It is used to prevent gouty attacks. It, too, may precipitate nephrolithiasis.

3) The correct answer is
C. The most likely diagnosis is a dystonic reaction to the droperidol. Droperidol causes its antiemetic effect by antagonizing dopaminergic receptors in the vomiting center (central chemoreceptor zone) of the brain. This antidopaminergic action can produce torticollis or other dystonias.

A cerebral vascular accident (choice A) is unlikely given that the patient is alert and oriented, has no detectable language deficit, and has an otherwise nonfocal neurologic examination.

A conversion disorder (choice B) is unlikely since the patient has no prior history of a psychiatric disorder and has a viable medical reason (dystonia from droperidol) for her neuromuscular deficit.

Munchausen syndrome (choice D) is also unlikely since the patient had valid medical reasons for her initial admission and your current visit. We are also not informed of any prior history of hospitalizations or seeking of medical attention without appropriate cause.

A seizure (choice E) is similarly unlikely since the patient has no history of a seizure disorder and is alert, oriented, and conversant.

4) The correct answer is
E. This is stasis dermatitis, which is a persistent inflammation of the skin of the lower legs. The condition is often related to varicose veins, although it has been postulated that the true cause may instead be perivascular fibrin deposition and abnormal small vessel vasoconstrictive reflexes. The presentation illustrated is typical. Most patients are relatively asymptomatic and may not seek medical attention until the edema becomes severe or the lesions become complicated by secondary bacterial infection or ulceration. It is important to increase the venous return to the heart by elevating the ankles while resting and use of properly fitted support hose. Local topical tap water compresses can be helpful. Purulent lesions can be treated with hydrocolloid dressings. Ulcers are treated with compresses and bland dressings, such as zinc oxide paste.

Atopic dermatitis (choice A) typically involves the antecubital and popliteal fossas, eyelids, neck, and wrists.

Cellulitis (choice B) is a bacterial infection of the subcutaneous tissues, and causes local erythema, tenderness, and often lymphangitis.

Lichen simplex chronicus (choice C) is a skin rash caused by chronic scratching characterized by dry, scaling, well-demarcated, hyperpigmented plaques.

Nummular dermatitis (choice D) causes widespread coin-shaped, crusted skin lesions.

5) The correct answer is
E.Nocardia asteroides is an aerobic soil saprophyte that can cause acute or chronic infectious disease often characterized by granulomatous-suppurative lesions that may become widely disseminated. Many, but not all, patients have underlying causes for immunodeficiency, including advanced age, lymphoreticular malignancies, organ transplantation, high dose corticosteroid therapy, or (increasingly commonly) AIDS. Disseminated nocardiosis usually starts as a pulmonary infection that can resemble either a severe pneumonia or tuberculosis. Once dissemination occurs, metastatic brain abscesses are particularly common, occurring in as many as 1/3 of patients with nocardiosis. Nocardiosis is treated with sulfa drugs, such as sulfadiazine or trimethoprim-sulfamethoxazole, for periods of months.

Actinomyces (choice A) is very similar to Nocardia, but is not acid-fast.

Aspergillus(choice B) is a fungus.

Burkholderia(choice C)pseudomallei is a gram-negative bacillus that causes melioidosis, which is characterized by lung involvement or disseminated infection.

Francisella(choice D)tularensis causes tularemia, which is usually acquired by contact with infected wild rabbits.

By dr_kals Posted in 1 Tagged

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