Upper respiratory tract infection

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Diagnostic approach

• Targeted clinical evaluation; usually no testing indicated
• Disease-specific (e.g., streptococcus, COVID-19) rapid test or PCR if there is high suspicion
• Respiratory viral panel if there is atypical presentation or diagnostic uncertainty
• Neck imaging if croup (AP x-ray) or epiglottitis (lateral x-ray or CT with contrast) is suspected

Red flag features

• Worsening symptoms after initial improvement
• Trismus
• Drooling
• Muffled voice
• Signs of respiratory distress
• Clinical features of sepsis

Management checklist

• Start disease-specific management if underlying pathogen is identified (e.g., antibiotics for GAS pharyngitis).
• Rest and hydration
• Avoid irritants to the upper respiratory tract (e.g., tobacco products and alcohol).
• Ibuprofen and/or acetaminophen as needed for pain and/or fever
• Honey or throat lozenges
• Head of the bed elevation
• Warm packs to the face
• Saline irrigation
• Consider short course of intranasal decongestants, e.g., oxymetazoline.
• Consult ENT or anesthesia immediately if patients have signs of airway compromise or signs of respiratory distress.

Life-threatening causes

• Pertussis in infants < 6 months of age
• Epiglottitis
• Severe influenza
• Severe COVID-19

Upper respiratory tract infections (URTIs) involve structures at or above the vocal cords, e.g., the nasal cavity, sinuses, pharynx, and/or larynx. URTIs include the common cold, acute rhinosinusitis, pharyngitis, laryngitis, influenza, croup, and COVID-19. Most URTIs are caused by viruses such as the rhinovirus. URTIs more commonly occur in the fall and winter and are especially common in children. Typical clinical manifestations include rhinorrhea, nasal congestion, sore throat, and cough. Diagnosis is generally clinical, although diagnostic testing may be performed to assess for specific infections (e.g., influenza, COVID-19, group A streptococcal pharyngitis). In most cases, treatment is supportive, with symptoms typically resolving within 14 days. Antibiotics are not indicated unless there is a confirmed bacterial infection.

• More commonly occur in the fall and winter [2]
• Higher incidence in children than adults [3]
  • Children: 6–10 per year
  • Adults: 2–4 per year

Epidemiological data refers to the US, unless otherwise specified.

Most URTIs are caused by viruses. [4]

Viral

• Rhinovirus
• Coronavirus
• Influenza virus [3]
• Respiratory syncytial virus (RSV)
• Adenovirus
• Parainfluenza virus
• Human metapneumovirus
• Epstein-Barr virus
• Enterovirus

Bacterial

• Streptococcus pneumoniae
• Streptococcus pyogenes
• Haemophilus influenzae
• Mycoplasma pneumoniae
• Moraxella catarrhalis

Many of the pathogens that cause URTI can also cause lower respiratory tract infections (LRTIs). [2][4]

Focused history

• Symptom duration: typically ≤ 14 days [3]
• Common features of URTI [3]
  • Sore throat
  • Nasal congestion
  • Rhinorrhea (with or without purulence)
  • Cough
  • Fever (esp. among pediatric patients)
• Exposures
  • Recent travel history
  • Contact with infectious individuals in the past week [3]
• Vaccination status: e.g., COVID-19 vaccination, Hib vaccination, influenza vaccination
• Targeted review of systems: e.g., HEENT, pulmonary

Focused physical examination

• Sinus, nose, and throat examination
• Pulmonary examination including assessment for pathological breath sounds

Fever is more common among pediatric than adult patients, and typically lasts for 2–3 days. [3]

Outpatient treatment of URTI is appropriate for most patients; complications are rare.

Approach

• Check vital signs.
• Urgently evaluate patients with red flags for URTI to assess for:
  • Life-threatening causes of URTI
  • Complications, e.g., secondary bacterial infection
• Consult ENT or anesthesia immediately if patients have signs of airway compromise or signs of respiratory distress.

Red flags for URTI

• Worsening symptoms after an initial period of improvement [5]
• Trismus, drooling, muffled voice [6]
• Signs of respiratory distress [7][8]
• Clinical features of sepsis [8]

Life-threatening causes of URTI

• Pertussis in infants < 6 months of age
• Epiglottitis
• Severe COVID-19
• Severe influenza

Most URTIs can be diagnosed clinically. Consider diagnostic studies in selected patients.

Nonspecific laboratory studies

• Routine studies: to support the diagnosis and/or determine disease severity
  • CBC may show:
    • Lymphopenia, e.g., in COVID-19 [9]
    • Lymphocytosis, e.g., in pertussis, influenza, infectious mononucleosis [8][10][11]
  • ESR and CRP may be elevated. [12]
  • BMP and liver chemistries may show signs of end-organ damage in severe disease (e.g., severe COVID-19).
• Blood cultures: Consider in severe disease (e.g., epiglottitis) to evaluate for concurrent bacteremia.
• ABG: Obtain in patients with signs of respiratory distress. [13][14]

Disease-specific laboratory studies

Consider specific studies based on clinical suspicion to support treatment and/or disposition decisions.

• Rapid strep test: : suspected acute bacterial tonsillopharyngitis
• Heterophile antibody test: : suspected infectious mononucleosis [11]
• Disease-specific NAATs (e.g., PCR) in patients with:
  • Indications for influenza testing [8]
  • COVID-19 symptoms and/or known exposure [15]
  • Suspected pertussis
  • Risk factors for severe RSV infection
• Respiratory viral panel
  • Can differentiate between different viral etiologies of URTIs (e.g., influenza, parainfluenza, RSV)
  • Not routinely indicated
  • May be considered in certain patients, e.g.:
    • Those with an atypical presentation
    • If there is diagnostic uncertainty in suspected croup

Imaging

Consider imaging to support the diagnosis, determine disease severity, and/or evaluate for complications.

• Chest imaging (CXR or CT scan): to evaluate for pneumonia [16][17]
• Neck imaging
  • Anterior-posterior x-ray neck: to evaluate for croup [18]
  • Lateral x-ray neck: to evaluate for epiglottitis in children [19]
  • CT neck with IV contrast [20][21][22]
    • Adults: to rule out differential diagnoses in patients with suspected epiglottitis
    • Children: to rule out differential diagnoses and/or assess for congenital abnormalities in croup
• CT maxillofacial with or without IV contrast: in patients with red flags for rhinosinusitis

Outpatient treatment of URTI is appropriate for most patients; complications are rare.

General principles [2][23]

• Recommend rest and adequate hydration (e.g., 6–10 glasses of fluid a day).
• Advise patients to avoid smoking and alcohol use.
• Offer symptomatic treatment as needed.
• Provide specific treatment if indicated, e.g.:
  • Treatment of influenza
  • Management of COVID-19
  • Antibiotics only for disease-specific indications (e.g., GAS pharyngitis)
• Counsel on return precautions.

Do not prescribe antibiotics without confirmation of a bacterial infection, as antibiotics do not treat viral infections and may cause harm, e.g., drug hypersensitivity reaction, C. difficile infection. [7]

Symptomatic treatment [2][23][29]

• General
  • Zinc (e.g., zinc acetate or gluconate lozenges) and probiotics (e.g., containing Lactobacillus casei) have been shown to shorten symptom duration. [30][31]
  • Oral antihistamine/decongestant combinations may improve symptoms but can cause adverse effects, e.g., dry mouth and dizziness.
• Rhinorrhea or sinus congestion
  • Elevate the head of the bed to improve sinus drainage.
  • Apply warm packs to the face for 5–10 minutes 3 times a day for facial pain. [2]
  • Nasal saline irrigation
  • Intranasal decongestants, e.g., oxymetazoline
• Pain or fever: analgesics, e.g., ibuprofen and/or acetaminophen
• Cough: nonpharmacological measures may be beneficial, e.g., honey [23][32]

Antitussives (e.g., codeine, dextromethorphan) and expectorants (e.g., guaifenesin) are not effective for URTI-associated cough. [29]

Return precautions [3]

• Dyspnea
• Chest pain
• Productive cough
• Fever > 38.9°C (> 102°F)
• Severe headache or facial pain
• Dizziness, confusion
• Symptom duration > 14 days (other than cough)

• Infectious
  • LRTIs, e.g., pneumonia
  • Acute HIV infection
  • Measles
• Noninfectious
  • Allergic rhinitis
  • Upper airway cough syndrome
  • Vasomotor rhinitis
  • Asthma exacerbation
  • Gastroesophageal reflux disease

The differential diagnoses listed here are not exhaustive.

Most URTIs are mild and self-limited and rarely cause complications. [2]

• LRTIs
• Otitis media
• Secondary bacterial infection
• See also the respective articles for complications of specific causes of URTI, e.g.:
  • Sinusitis complications
  • Pertussis complications

We list the most important complications. The selection is not exhaustive.

• Educate patients and caregivers on respiratory hygiene and hand hygiene.
• Recommend regularly cleaning and disinfecting surfaces that are touched often, e.g., door handles.
• Advise patients to stay at home until both:
  • Afebrile for 24 hours without the use of antipyretics
  • Symptoms are improving
• Ensure age-appropriate immunizations are up-to-date, including seasonal vaccines, e.g.:
  • Influenza vaccination
  • COVID-19 vaccination
  • RSV vaccination

• One-Minute Telegram 107-2024-2/3: To mask or not to mask: wearing face masks may help prevent respiratory infections

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