AAFP Board Review – ID- Questions with Guaranteed Accurate Answers

A 4-week-old white male is brought to your office with a 2-week history of increasing dyspnea, cough, and poor feeding. The child appears nontoxic and is afebrile. On examination you note conjunctivitis, and a chest examination reveals tachypnea and crackles. A chest film shows hyperinflation and diffuse interstitial infiltrates and a WBC count reveals eosinophilia. What is the most likely etiologic agent? (check one) A. Staphylococcus species B. Chlamydia trachomatis C. Respiratory syncytial virus D. Parainfluenza virus - correct answer B. Chlamydial pneumonia - usu in infants 3 - 16 wks; pt sick for weeks - infant nontoxic & afebrile, tachypneic w/ prominent cough - physical examination: diffuse crackles with few wheezes, and conjunctivitis (50% of cases). - CXR: hyperinflation and diffuse interstitial or patchy infiltrates. Not Staphylococcal pneumonia - fever, initial expiratory wheeze like bronchiolitis - PE: abdominal distress, tachypnea, dyspnea, and localized or diffuse bronchopneumonia or lobar disease - CBC: leukocytosis. Not RSV - rhinorrhea and pharyngitis, followed in 1-3 days by a cough and wheezing. Auscultation of the lungs will reveal diffuse rhonchi, fine crackles, and wheezes, but the chest film is often normal. - If the illness progresses, coughing and wheezing increase, air hunger and intercostal retractions develop, and evidence of hyperexpansion of the chest is seen. - WBC count will be normal or elevated, and the differential may be normal or shifted either to the right or left. - Chlamydial infections can be differentiated from respiratory syncytial virus infections by a history of conjunctivitis, the subacute onset and absence of fever, and the mild wheezing. There may also be eosinophilia. Not Parainfluenza virus infection - typical cold symptoms. - Eight percent of infections affect the upper respiratory tract. - In children hospitalized for severe respiratory illness, parainfluenza viruses account for about 50% of the cases of laryngotracheitis and about 15% each of the cases of bronchitis, bronchiolitis, and pneumonia. One day after a nurse performs CPR on an emergency-department patient, she learns that the patient had meningococcal meningitis. Which one of the following is the most appropriate chemoprophylaxis for this condition? (check one) A. Penicillin G benzathine (Bicillin LA), 1.2 million units intramuscularly B. Rifampin, 600 mg every 12 hours for 2 days C. Oral prednisone, 40 mg daily for 5 days D. Quadrivalent meningococcal vaccine E. No prophylaxis - correct answer B. Rifampin, 600 mg q12 x 12 days - Rifampin has been shown to be 90% effective in eliminating meningococcus from the nasopharynx. - also minocycline and ciprofloxacin - even high doses of penicillin may not eradicate nasopharyngeal meningococci. - Meningococcal vaccine appears to have clinical efficacy, but it usually takes more than 5 days to become effective. A 30-year-old ill-appearing male presents with right hand and arm pain and a rapidly expanding area of redness. On examination he temp is 38.9°C (102.0°F), a pulse rate of 120beats/min, and a blood pressure of 116/74 mm Hg. He also has erythema from the dorsal hand to the elbow, violaceous bullae on the dorsal hand and wrist, and severe pain with dorsiflexion of the wrist or fingers. Which one of the following is the most appropriate initial step in the management of this patient? A. Oral dicloxacillin and outpatient follow-up within the next 24 hours B. Intravenous metronidazole C. Consultation with an infectious disease specialist D. Immediate surgical consultation for operative debridement