An 18-year-old man comes to the office due to an irritating, dry cough. He developed symptoms approximately 3 weeks ago after returning from a Caribbean cruise with his family. The patient visited several islands during the trip and participated in many activities, including hiking and water sports. He initially had clear rhinorrhea for a week, followed by a dry cough that lasted a week. This week, the coughing episodes have worsened, now occur without warning, and have twice caused vomiting. The patient has no chronic medical conditions and last received routine childhood vaccinations at age 11. Vital signs are normal. Examination shows nasal congestion. The lungs are clear to auscultation. There is bilateral muscle tenderness between the ribs. The lymph nodes and spleen are not enlarged. Which of the following risk factors is most associated with this patient's diagnosis?

Question

An 18-year-old man comes to the office due to an irritating, dry cough.  He developed symptoms approximately 3 weeks ago after returning from a Caribbean cruise with his family.  The patient visited several islands during the trip and participated in many activities, including hiking and water sports.  He initially had clear rhinorrhea for a week, followed by a dry cough that lasted a week.  This week, the coughing episodes have worsened, now occur without warning, and have twice caused vomiting.  The patient has no chronic medical conditions and last received routine childhood vaccinations at age 11.  Vital signs are normal.  Examination shows nasal congestion.  The lungs are clear to auscultation.  There is bilateral muscle tenderness between the ribs.  The lymph nodes and spleen are not enlarged.  Which of the following risk factors is most associated with this patient's diagnosis?

Quizplus · Accepted Answer

11ec25c8_d6cb_a639_bc81_d325726c4dfe_MD0003_00 This patient's prolonged and paroxysmal cough with posttussive emesis is suggestive of Bordetella pertussis infection (whooping cough). Symptoms typically begin with malaise, rhinorrhea, and mild cough lasting 1-2 weeks. Patients then develop a paroxysmal cough in which severe bouts of coughing may be followed by an inspiratory whoop (particularly in young children) and, often, posttussive emesis. Intercostal muscle tenderness, as seen in this patient, can also occur because of forceful coughing episodes. When classic symptoms are present, the diagnosis is clinical. Nasopharyngeal PCR testing is helpful for providing epidemiologic data or confirming the diagnosis. Macrolides (eg, azithromycin, clarithromycin) are the first-line treatment and should be initiated based on clinical suspicion without waiting for confirmation. The infection rate and severity of the disease have declined because of routine immunization that includes five doses of diphtheria, tetanus, and acellular pertussis (DTaP) in early childhood and tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) booster at age 11-12. However, lifelong immunity is not conferred from vaccination or prior pertussis infection. Acquired immunity wanes 5-10 years postvaccination, allowing fully immunized patients to be susceptible to infection, as seen in this patient. (Choice A) Psittacosis, caused by Chlamydophila psittaci, presents with fever, cough, and headache after exposure to exotic birds. In addition, rales are classically heard on auscultation. This patient is afebrile with clear lung sounds. (Choice B) Exposure to contaminated water via poorly maintained air conditioning systems is a risk factor for Legionella pneumonia (Legionnaires disease). In addition to cough, fever and focal rales are typically present. (Choice C) Swimming in fresh water contaminated with Naegleria fowleri can lead to acute meningoencephalitis and death. Symptoms include fever, headache, and altered mental status, none of which are present in this patient. (Choice D) HIV spread via unprotected sexual intercourse can lead to a wide range of pulmonary diseases, including bacterial pneumonia and tuberculosis. Patients are typically febrile with lymphadenopathy, which is not seen in this patient. Educational objective: Pertussis should be suspected with paroxysmal cough and posttussive emesis, even if patients are fully immunized. Vaccination reduces infection risk but immunity wanes over 5-10 years. References: Pertussis: a reemerging infection. (http://www.ncbi.nlm.nih.gov/pubmed/24364571) What is wrong with pertussis vaccine immunity? The problem of waning effectiveness of pertussis vaccines. (http://www.ncbi.nlm.nih.gov/pubmed/28289064) Waning and aging of cellular immunity to Bordetella pertussis. (http://www.ncbi.nlm.nih.gov/pubmed/26371178)

An 18-Year-Old Man Comes to the Office Due to an Irritating