What is the diagnosis and management approach for a 15-year-old patient presenting with cough, cold, and fever that has lasted over a week?

Management of Cough, Cold, and Fever in a 15-Year-Old

For a 15-year-old with cough, cold, and fever lasting over a week, this represents subacute cough (3-8 weeks duration) and should be managed by first screening for red flags and life-threatening conditions, then treating empirically for the most common causes: postinfectious cough, upper airway cough syndrome (UACS), transient bronchial hyperresponsiveness, or asthma. 1

Initial Assessment: Screen for Red Flags

Before proceeding with management, immediately evaluate for these warning signs that require urgent intervention 1:

• Hemoptysis (any blood in sputum)
• Prominent dyspnea, especially at rest or at night
• Systemic symptoms: fever persisting beyond typical viral course, unintentional weight loss
• Abnormal respiratory examination findings (crackles, wheezing, decreased breath sounds)
• Hoarseness or voice changes
• Difficulty swallowing when eating or drinking
• Recurrent pneumonia history

If any red flags are present, obtain chest radiograph immediately and consider life-threatening diagnoses including pneumonia, severe asthma exacerbation, pulmonary embolism, or tuberculosis (especially in endemic areas or high-risk populations). 1

Duration Classification and Diagnostic Approach

Since symptoms have lasted "over a week," clarify the exact duration 1:

• Acute cough (<3 weeks): Most likely viral upper respiratory infection or acute bronchitis
• Subacute cough (3-8 weeks): Most commonly postinfectious cough following viral illness
• Chronic cough (>8 weeks): Requires systematic evaluation for UACS, asthma, GERD, or other causes

At 15 years of age, this patient should be managed using adult cough algorithms, not pediatric protocols. 1

Management Algorithm for Subacute Cough (Most Likely Scenario)

Step 1: Determine if Postinfectious

Ask specifically whether the cough began following an obvious respiratory infection (cold, flu-like illness). 1

If YES (postinfectious cough):

• Most common causes: Upper airway cough syndrome (UACS) from persistent postnasal drip (48.4%), transient bronchial hyperresponsiveness (33.2%), asthma exacerbation (15.8%), or pertussis 1
• First-line empiric treatment: First-generation antihistamine plus decongestant for UACS 2
• Consider inhaled corticosteroids if features suggest bronchial hyperresponsiveness or asthma (nocturnal cough, exercise-induced symptoms, wheezing) 1
• Consider pertussis testing if paroxysmal cough, post-tussive vomiting, or inspiratory whoop present 1

If NO (non-postinfectious):

• Manage as chronic cough using the systematic approach below 1

Step 2: Symptomatic Management

For fever management 3, 4, 5:

• Acetaminophen 10-15 mg/kg every 4-6 hours (maximum 5 doses/24 hours) for discomfort, NOT solely to reduce temperature numbers
• Never use aspirin in patients under 16 years due to Reye's syndrome risk
• Fever aids immune response; treat only when patient is uncomfortable

For cough and cold symptoms 6, 2, 7:

• First-generation antihistamine plus decongestant combination is most effective for common cold symptoms
• Avoid over-the-counter cough medications in isolation (limited efficacy)
• Encourage adequate fluid intake

Step 3: Follow-Up and Reassessment

Schedule follow-up in 4-6 weeks to assess treatment response. 1

• If cough resolves: Diagnosis confirmed, discontinue treatment
• If cough persists beyond 8 weeks: Transition to chronic cough evaluation (see below)
• If symptoms worsen or new red flags develop: Re-evaluate immediately 3, 4

If Cough Becomes Chronic (>8 Weeks)

Systematically evaluate and treat the three most common causes sequentially 1:

1. Upper Airway Cough Syndrome (UACS): Treat with antihistamine-decongestant combination
2. Asthma: Obtain spirometry with bronchodilator reversibility testing; treat with inhaled corticosteroids and bronchodilators
3. Gastroesophageal Reflux Disease (GERD): Treat with proton pump inhibitor plus dietary/lifestyle modifications

Critical principle: Multiple causes often coexist (67% of cases), so maintain all partially effective treatments while adding new therapies. 1

Investigations to Consider

Obtain chest radiograph if 1, 3:

• Red flags present
• Abnormal respiratory examination
• Cough persists beyond 8 weeks
• Clinical suspicion of pneumonia

Obtain spirometry (pre- and post-bronchodilator) if 1:

• Asthma suspected
• Cough becomes chronic
• Patient can reliably perform test (usually >6 years old)

Do NOT routinely perform 1:

• Skin prick testing
• CT chest
• Bronchoscopy
• Tuberculosis testing (unless endemic area or high-risk population)

Critical Pitfalls to Avoid

• Do not prescribe antibiotics empirically without evidence of bacterial infection; most cases are viral 3, 4, 7
• Do not use antipyretics solely to reduce fever numbers; treat only for patient comfort 3, 5
• Do not ignore the possibility of multiple simultaneous causes of cough; maintain partially effective treatments 1
• Do not use aspirin in this age group 3, 4, 5
• Do not assume single-cause etiology; 67% of chronic cough cases have multiple contributing factors 1

When to Refer or Escalate Care

Immediate referral if 1, 3:

• Any red flag symptoms present
• Respiratory distress (tachypnea >50 breaths/minute, retractions, grunting)
• Cyanosis
• Severe dehydration or inability to maintain oral intake
• Suspected pneumonia with clinical signs

Refer to specialist if 1:

• Complete workup and appropriate therapeutic trials fail to identify cause
• Cough remains unexplained after systematic evaluation