Upper Respiratory Tract Infections

Upper respiratory tract infections Common cold • • • • Cause: rhinovirus Clinical features: - Onset: gradual - Fever: rare and is low grade - Increase in nasal blood flow and vascular permeability -> rhinorrhoea, congestion and postnasal drip. - Increase concentration of leucocytes and their enzymes in the nasal mucosa -> yellow-green nasal discharge - Irritation of the upper airways -> sneezing and coughing - No prominent localising features such as fascial pressures. - Lungs clear on auscultation Diagnosis: - Mainly clinically - Viral detection techniques such as a PCR and immunoassays Treatment: - Supportive: hydration, analgesia such as Panadol and NSAIDs, nasal decongestions such as oxymetazoline and chlorpheniramine. - Antibiotics are not indicated unless a secondary bacterial infection is suspected. Influenza • • • • Cause: influenza virus Clinical features: - Onset: sudden. - Fever is highly common. - Chills - Myalgia - Sore throat - Cough due to development acute bronchitis that is dry cough the small amounts of clear or blood-tinged sputum - Hypotension and bradycardia are common. Diagnostics: - In the flu season usually a clinical diagnosis. - PCR - Rapid molecular assays. - Serological testing and viral cultures are not recommended for diagnosis - Normal or high lymphocytes - Relative lymphocytosis Treatment: - Oral hydration therapy - Antipyretics (e.g. ibuprofen, paracetamol that reduce fever). - Oral analgesics - Antitussives to relieve the dry cough -> suppression of the central cough in the brain and inhibition of the stretch receptors in the lungs. E.g. benzonatate. Anti-viral medications -> neuraminidase inhibitors e.g. oseltamivir ✓ Indications all patients with one more of the following: severe or progressive illness, hospitalisation required, high risk for complications of influenza (adults over 50, children under 5, especially those under 2, those who are pregnant and those who will be pregnant or those who are in less than or equal to less than 2 weeks of postpartum during the influenza seasons, those which chronic conditions such as asthma, heart disease, CKD, DM etc., those who are immunocompromised, BMI greater than 40, nursing home residents. ✓ Complications: pneumonia, secondary bacterial bronchitis, sinuses, acute otitis media, croup, etc, AKI< pericarditis, myocarditis etc. COVID-19 • • Cause: SARS-CoV-2 Clinical features: - Onset: variable - Fever: common - Cough, shortness of breath, loss of smell and or taste. - Sore throat - Rhinitis - Headache - Myalgia - Loss of appetite. • Diagnosis: - PCR - Antigen testing • Management: - Staying at home - Wearing a mask - Hand hygiene - Rest - Hydration - Antipyretics and analgesia as needed - Antitussives e, g. benzonatate - Prone positioning -> relieves dyspnea Acute tonsillopharyngitis • • • Cause: rhinovirus, S. pyrogens Clinical features: - Viral: gradual onset, low grade fever (rare), rhinorrhoea, cough, hoarseness - Bacterial: sudden onset, fever is common, sore throat, painful swallowing, inflammation of the pharynx and tonsils and no cough - Tonsillar erythema - Cervical lymphadenitis - Scarlet fever: strawberry tongue, scarlatiniform rash - Necrotizing infection Diagnosis: - Rapid strep test -> swabbing the patient’s tonsils at the back of the throat -> identifies the presences of GAS (positive RADT) -> time to run the test -> 5 to 10 minutes. - Throat culture: confirmatory test to rule out GAS infection -> causative bacteria and their antibiotic susceptibility -> time to result -> 24 to 48 hours. • Management: - Supportive care - Antibiotic therapy for patients with confirmed GAS • Tonsillectomy: - Indications: extreme hypertrophy of the tonsils, chronic tonsilitis etc. Laryngitis • • • • Cause: H. influenza, s. pneumonia, S.pyrogens Clinical features: - Hoarseness - Barking cough - Sore and dry throat - Enlarged lymph nodes - Odynophagia - Throat clearing post-nasal drip - Globus sensation Diagnosis: - Laryngoscopy Management: - Supportive care: vocal rest -> avoid shouting, using a load voice and forced whispering, analgesia as needed, mucosal hydration (drinking water), avoid medications that dry the airway mucosa e.g. antihistamines, anticholinergics, decongestants and certain hypertensives e.g. ACE inhibitors and inhaled corticoisteroids, avoid exposure to airway irritants via smoking cessation. Epiglottis • • • • • Causes: - H. influenzae - S. pneumoniae - S. pyrogens Pathophysiology: bacteria invades the tissue of the epiglottis (either directly or through hematogenous spreading) -> supraglottic inflammation and edema -> narrowing of the airway -> airway obstruction (may be complete or partial). Clinical features: - No cough - Drooling - Muffled voice - Acute onset of fever - Tripod positioning eases respiration as the airway diameter is increased by leaning forwards and extending the neck in seated position. - Respiratory distress -> inspiratory retractions, cyanosis - Inspiratory stridor: a pathological high pitched breath sounds produced by a partially obstructed airway, typically at or above the level of the trachea. - Tenderness to palpations over the larynx/throat. Diagnosis: - Visualisation via the pharyngoscopy -> oropharyngeal examination with a tongue blade: characteristic findings -> cherry red epiglottis, pooled secretions, inflammation and edema of the supraglottic structure Management: - Monotherapy of antibiotics such as cephalosporins such as ceftriaxone or beta lactams with beta lactam inhibitors. - Adjunctive therapy: empiric steroids -> dexamethasone - IV fluid resuscitation. Croup (laryngotracheobronchitis) • • • • Causes: parainfluenza virus Clinical features: - Gradual onset. - Fever is common and is low grade - Barking cough - Stridor. - Dyspnoea - Diseased airway entry - Hypoxemia Diagnosis: - Imaging of the chest and the neck - Respiratory viral panel ->PCR - CBC - Blood gas: hypoxia, and/or CO2 retention Management: - Avoid examining the throat as this may participate airway obstruction - If signs of hypoxemia: supplemental oxygenation and intubation - Give all patients dexamethasone - Antipyretics - IV fluids - Nebulised racemic epinephrine Pertussis • Cause: - B. pertussis • • • - Clinical features: - Gradual onset - Fever is of low grade and is usually rare - Paraxoyms of whooping cough - Rhinorrhoeas (rare) - Myalgia (rare) - Sore throat (rare) Diagnosis - Clinical diagnosis - PCR - Bacterial culture Treatment - Macrolides mainly azithromycin Not having enough time