When are antibiotics indicated for Upper Respiratory Infections (URIs)?

When to Prescribe Antibiotics for Upper Respiratory Infections

Antibiotics should NOT be prescribed for most URIs, as over 90% are viral in origin and self-limiting; prescribe antibiotics only for confirmed bacterial infections meeting strict diagnostic criteria: acute otitis media with middle ear effusion and inflammation, acute bacterial sinusitis with specific symptom patterns, or confirmed group A streptococcal pharyngitis. 1, 2

Viral URIs: No Antibiotics Indicated

The vast majority of URIs—including the common cold, acute bronchitis, viral pharyngitis, and uncomplicated rhinosinusitis—are viral and require only supportive care 1, 2. Antibiotics provide no benefit for viral infections and cause more harm than good, with the number needed to harm (8) exceeding the number needed to treat (18) for conditions like acute rhinosinusitis 1, 2.

Supportive Care Recommendations:

• Analgesics and antipyretics for pain and fever 1, 2
• Adequate hydration 3
• Intranasal saline irrigation 1, 2
• Intranasal corticosteroids 1, 2
• Decongestants and cough suppressants as needed 2

Critical Pitfall: Purulent (green or yellow) nasal discharge or sputum does NOT indicate bacterial infection and should NOT trigger antibiotic prescribing 2, 4.

Bacterial URIs: When Antibiotics ARE Indicated

1. Acute Otitis Media (AOM)

Diagnostic Criteria (all three required) 1, 3:

• Abrupt onset of symptoms
• Middle ear effusion (moderate/severe bulging of tympanic membrane, OR otorrhea not from otitis externa, OR mild bulging with ear pain or erythema)
• Signs of middle ear inflammation

Treatment 3:

• First-line: Amoxicillin 90 mg/kg/day 3, 5
• High-dose amoxicillin-clavulanate (90 mg/6.4 mg per kg per day) if recent antibiotic use (within 4-6 weeks) or moderate disease 3
• Consider watchful waiting for uncomplicated cases in children >2 years with reliable follow-up 3

2. Acute Bacterial Rhinosinusitis (ABRS)

Diagnostic Criteria (one of the following) 1, 2:

• Persistent symptoms: Nasal discharge or daytime cough >10 days without improvement
• Severe symptoms: Fever ≥39°C AND purulent nasal discharge for ≥3 consecutive days
• Worsening symptoms ("double sickening"): New or worsening fever, headache, or nasal discharge after initial improvement from typical viral URI

Treatment 1, 2, 3:

• IDSA recommends amoxicillin-clavulanate as first-line 1, 2
• Alternative societies recommend amoxicillin alone 1
• Watchful waiting is appropriate for uncomplicated cases 1
• No role for imaging in diagnosis 1

3. Group A Streptococcal (GAS) Pharyngitis

Diagnostic Approach 1, 3:

• Only test if ≥2 of the following present: fever, tonsillar exudate/swelling, swollen/tender anterior cervical nodes, absence of cough 3
• Confirm diagnosis with rapid antigen detection test or throat culture BEFORE prescribing antibiotics 1, 3

Treatment 3:

• First-line: Amoxicillin or penicillin 3, 5
• Once-daily dosing of amoxicillin is acceptable 3

Clinical Decision Algorithm

For fever and cough of ≤2 days duration 2:

• Provide symptomatic treatment only
• Schedule clinical follow-up in 2-3 days
• Pneumonia is unlikely without ALL of: tachycardia (HR >100), tachypnea (RR >24), fever >38°C for >3 days, abnormal chest exam 2

Consider antibiotics only if 2:

• Fever >38°C persists for >3 days AND meets criteria for bacterial infection above
• Suspected/confirmed pneumonia (obtain chest X-ray) 2
• High-risk patients: age >75 with fever plus cardiac failure, insulin-dependent diabetes, or serious neurological disorders 2
• COPD patients with respiratory insufficiency 2

Harms of Inappropriate Antibiotic Use

Adverse effects range from common to life-threatening 1, 3:

• Common: Diarrhea, rash (especially with amoxicillin-clavulanate) 3
• Severe: Stevens-Johnson syndrome 3
• Life-threatening: Anaphylaxis 3
• Long-term: Disruption of microbiome potentially contributing to inflammatory bowel disease, obesity, eczema, asthma 3
• Population-level: Antibiotic resistance 1, 2, 3

Follow-Up Requirements

Reassess patients within 48-72 hours if 2, 3:

• Symptoms not improving
• Clinical deterioration occurs
• Initial watchful waiting approach was chosen 3

Treatment should continue for minimum 48-72 hours beyond symptom resolution or bacterial eradication 5.