What is the differential diagnosis and management for a 37-year-old female presenting with cough, sudden sharp pain in the upper chest exacerbated by coughing, fatigue, and sore throat?

Differential Diagnosis for 37-Year-Old Female with Cough, Chest Pain, Fatigue, and Sore Throat

This presentation most likely represents an acute upper respiratory tract infection (common cold) with associated acute bronchitis, though pertussis, atypical pneumonia, and less commonly tuberculosis or other infections must be considered given the constellation of systemic symptoms. 1

Most Likely Diagnoses

Acute Viral Upper Respiratory Infection with Bronchitis

• This is the most common cause of acute cough (lasting <3 weeks) with associated sore throat and fatigue. 1
• The sudden sharp chest pain exacerbated by coughing likely represents musculoskeletal chest wall pain from repetitive coughing rather than pleuropulmonary pathology. 2
• Fatigue and sore throat are typical systemic manifestations of viral respiratory infections. 3

Pertussis (Whooping Cough)

• Must be strongly considered in any adult with persistent cough, especially with paroxysmal features, given that adults are increasingly recognized as a reservoir for this infection. 2
• The combination of cough with chest pain during coughing episodes can occur with the forceful paroxysms characteristic of pertussis. 2
• Fatigue is a prominent systemic symptom in pertussis infection. 2
• A confirmed diagnosis requires either nasopharyngeal culture isolation or fourfold increase in IgG/IgA antibodies to pertussis toxin or filamentous hemagglutinin. 2

Atypical Pneumonia

• The combination of cough, chest pain, and systemic symptoms (fatigue, sore throat) raises concern for atypical pneumonia, particularly mycoplasma or chlamydia pneumoniae. 4, 3
• Chest radiograph is essential as the first imaging study to establish or exclude pneumonia. 4
• Pulse oximetry should be performed to assess for hypoxemia, which may be present even without obvious clinical signs. 4

Tuberculosis (Lower Probability but Important)

• While less likely in a 37-year-old without specific risk factors, TB should be considered when cough is accompanied by systemic symptoms like fatigue. 2
• In populations at increased risk, chronic cough should be defined as 2-3 weeks duration, making early TB consideration important. 2
• Chest radiograph and sputum for acid-fast bacilli should be obtained if risk factors are present or symptoms persist. 2

Critical Diagnostic Approach

Immediate Assessment Required

• Chest radiograph to differentiate pneumonia from bronchitis and identify any concerning pulmonary pathology. 4
• Pulse oximetry to detect hypoxemia. 4
• Detailed exposure history including sick contacts, immunization status (particularly pertussis vaccination), and any epidemiologic linkage to confirmed pertussis cases. 2

Red Flags Requiring Urgent Evaluation

• Hemoptysis (even if minimal). 2
• Fever persisting beyond 72 hours. 3
• Worsening dyspnea or chest pain. 5
• Hypoxemia on pulse oximetry. 4
• Weight loss or night sweats (suggesting TB or other serious pathology). 2

Specific Testing Based on Clinical Suspicion

• If pertussis is suspected based on paroxysmal cough or known exposure, obtain nasopharyngeal culture and paired acute/convalescent sera for pertussis antibodies. 2
• If pneumonia is suspected clinically or radiographically, sputum Gram stain and culture are crucial. 4
• If TB risk factors exist (immigration from endemic areas, immunosuppression, homelessness, incarceration), obtain sputum for acid-fast bacilli smear and culture. 2, 4

Management Strategy

For Presumed Viral Upper Respiratory Infection/Acute Bronchitis

• Combination first-generation antihistamine plus decongestant is the most effective treatment for cough due to common cold. 1
• Antibiotics are NOT indicated for immunocompetent adults with acute cough due to acute bronchitis. 5
• Adequate hydration and symptomatic management. 3
• Avoid cough-evoking irritants including cigarette smoke. 6

If Pertussis is Confirmed or Highly Suspected

• Macrolide antibiotic (azithromycin 500mg day 1, then 250mg daily for 4 days) should be initiated immediately, with isolation for 5 days from start of treatment. 2, 3
• Early treatment within the first few weeks diminishes coughing paroxysms and prevents disease spread. 2
• Treatment beyond the early catarrhal phase is unlikely to alter the clinical course but prevents transmission. 2

If Atypical Pneumonia is Suspected

• Empiric treatment with azithromycin (500mg day 1, then 250mg daily for 4 days) is appropriate for patients with respiratory infections and systemic symptoms. 3
• Reassessment within 48-72 hours to ensure clinical improvement. 3

If Symptoms Persist Beyond 3 Weeks

• Cough lasting >3 weeks transitions from acute to subacute, requiring evaluation for postinfectious cough, transient bronchial hyperresponsiveness, or chronic cough etiologies. 2
• Consider upper airway cough syndrome, asthma, or gastroesophageal reflux disease as potential causes. 2, 6

Common Pitfalls to Avoid

• Do not prescribe antibiotics reflexively for acute cough without evidence of bacterial pneumonia or pertussis. 5, 1
• Do not dismiss chest pain as purely musculoskeletal without first obtaining chest radiograph to exclude pneumonia or other pulmonary pathology. 4
• Do not overlook pertussis in adults, as it is increasingly recognized and vaccination immunity wanes over time. 2
• Do not assume fatigue is simply "viral" without considering more serious infections like atypical pneumonia or TB if risk factors or concerning features are present. 2, 4
• If symptoms worsen or fail to improve after 48-72 hours, reassessment is mandatory to consider alternative diagnoses or complications. 3, 5