A previously healthy 43-year-old man comes to the office during the early fall due to a 4-week history of cough. He initially had a "bad cold" that lasted about 10 days. The sneezing, runny nose, and muscle aches that accompanied the cold have improved, but the cough has persisted and worsened. The patient has "bursts of coughing" for several minutes as he feels unable to clear the mucus. On at least 5 occasions, these attacks were so severe that he vomited afterward. The patient is a children's karate teacher. He received all of his childhood vaccinations but has not seen a physician in many years. There is no history of recent travel. Vital signs and physical examination are normal. Chest x-ray is unrevealing. Which of the following is the most likely cause of this patient's symptoms?

Question

A previously healthy 43-year-old man comes to the office during the early fall due to a 4-week history of cough.  He initially had a "bad cold" that lasted about 10 days.  The sneezing, runny nose, and muscle aches that accompanied the cold have improved, but the cough has persisted and worsened.  The patient has "bursts of coughing" for several minutes as he feels unable to clear the mucus.  On at least 5 occasions, these attacks were so severe that he vomited afterward.  The patient is a children's karate teacher.  He received all of his childhood vaccinations but has not seen a physician in many years.  There is no history of recent travel.  Vital signs and physical examination are normal.  Chest x-ray is unrevealing.  Which of the following is the most likely cause of this patient's symptoms?

Quizplus · Accepted Answer

Pertussis (whooping cough) is a highly contagious infection transmitted via respiratory droplets. It was predominantly a childhood disease before vaccination became the norm; however, many cases now occur in adolescents/adults whose immunity has waned. The diagnosis should be considered in any adult with acute tracheobronchitis who has not had vaccination boosters. This patient may have contracted the disease during karate sessions with his students. Chest x-ray is unremarkable in most cases as there is no pulmonary consolidation. The phases of pertussis include: Pertussis is caused by the gram-negative coccobacillus Bordetella pertussis, which produces virulence factors that include adhesins and toxins. Pertactin, which forms the basis of the acellular pertussis vaccine, promotes B pertussis adherence to the ciliated upper respiratory epithelium. Tracheal cytotoxin subsequently promotes local tissue destruction, resulting in cough. Pertussis toxin causes excessive adenylate cyclase activity, which prevents effective phagocytosis and allows the organism to persist in alveolar macrophages and ciliated epithelial cells, leading to a prolonged disease course. Lymphocytosis, induced by pertussis toxin, is also common. (Choice A) This patient lacks the constitutional symptoms (eg, night sweats, weight loss, fever) and chest x-ray findings (eg, upper lobe infiltrates with cavitation) expected in pulmonary tuberculosis, which is caused by the acid-fast bacillus Mycobacterium tuberculosis. (Choice C) Streptococcus pneumoniae, a gram-positive diplococcus, is the most common cause of pneumonia and typically presents with lobar consolidation on chest x-ray. This patient's negative chest x-ray and lack of fever make pneumococcal pneumonia unlikely. (Choice D) Mycoplasma pneumoniae typically causes atypical pneumonia characterized by a persistent nonproductive cough, pharyngitis, ear pain, and constitutional symptoms (eg, fever, headache, malaise). Chest x-ray classically reveals a diffuse interstitial infiltrate. (Choice E) Examples of RNA viruses causing respiratory infections include respiratory syncytial virus, influenza, parainfluenza, rhinovirus, and corona virus. Although viral infections can cause a postinfectious cough for up to 8 weeks, severe paroxysmal coughing spells associated with post-tussive emesis in an adult without booster vaccinations are more concerning for pertussis. Educational objective: Pertussis should be considered in any adult who has not had updated vaccination boosters. The clinical presentation is a paroxysmal cough lasting >2 weeks that is associated with post-tussive emesis or inspiratory whoop after a severe coughing episode. __________ References: Pertussis: a reemerging infection. (http://www.ncbi.nlm.nih.gov/pubmed/24364571)

A Previously Healthy 43-Year-Old Man Comes to the Office During