OVERVIEW OF UPPER RESPIRATORY TRACT INFECTIONS(URTIs) Flashcards
Common cold(Rhinitis)
cause?
Most are caused by viruses(mostly rhinoviruses, coronaviruses, occasionally respiratory synctial viruses, human metapneumoviruses)
Rhinitis
MOTransmission
Mode of transmission: droplets and direct contact
Rhinitis
Pathogenesis?
Pathogenesis: depending on the virus, destruction of epithelial lining with associated acute inflammatory response
Release of inflammatory cytokines and infiltration of the mucosa by inflammatory cells
rhinitis
Incubation period?
Incubation period -48-72hrs
Rhinitis
Clinical features?
Clinical features- 1st symptom- sore/scratchy throat, then nasal discharge and obstruction
Others – cough(30%), fever (rare)
Nasal cavity examination- swollen and erythematous nasal turbinates
Usually persists for 1 week
Rhinitis
Diagnosis ?
Diagnosis – clinical
Laboratory work up- nasal smear- eosinophils ( allergic rhinitis), polymorphonuclear cells (uncomplicated colds)
Viral culture, Polymerase chain reaction, serologic methods
Bacteria culture( group A streptococcus etc)
Rhinitis
Differential diagnosis ?
Differential diagnosis
-Allergic rhinitis- prominent itching and sneezing
-Foreign body- bloody nasal secretions, foul smelling discharge
-Sinusitis- fever, headache, facial pain, periorbital oedema, persistence of rhinorrhoea or cough for > 14 days
rhinitis
Management?
Management- majorly symptomatic, the use of most drugs involved is controversial in children
-Nasal decongestants- xylometazoline, phenylephrine
First generation anti-histamines- chlorpheniramine
Topical anticholinergic- ipratropium bromide
Antipyretic- acetaminophen, because of the risk of Reye syndrome, aspirin should be avoided
Plenty of fluids and bed rest
Rhinitis
Complications?
Complications
Otitis media-
Sinusitis
Exacerbation of asthma
Rhinitis
Prevention?
Prevention
Good hand washing
Restriction of activities to avoid infecting others
Sinusitis(Rhinosinusitis)
Aetiology?
Aetiology- viruses, bacteria and fungi
Commonly implicated microorganisms- bacteria(streptococcus pneumoniae(30%) Haemophilus influenzae(20%), Moraxella catarrhalis(20%).
Sinusitis
Pathogenesis?
Pathogenesis - congestion and blockage of the nasal passages usually in response to viral infection or allergic rhinitis.
mucus cannot drain properly, providing an environment where bacteria or fungus can thrive.
NB; Persons with chronic nasal congestion, and particularly those with allergies and asthma may be more prone to developing acute sinusitis
Sinusitis
Clinical features?
Clinical features- non specific-
- Features of rhinitis lasting more than 10 to 14 days
- Fever
Thick yellow-green nasal drainage for at least three days in a row
sore throat, cough, nausea and/or vomiting
- Headache, usually in children age six or older
- Irritability or fatigue
- less commonly halithosis, decrease sense of smell and periorbital oedema
Sinusitis
Physical examination & Transillumination ?
Physical examination- erythema and swelling of the nasal mucosa, purulent nasal discharge
Transillumination- opaque sinus that transmits light poorly
Sinusitis
Diagnosis ?
Diagnosis- clinical
Sinus puncture and imaging - When treatment is ineffective and sinusitis persists, when symptoms are severe or suspicion of fungal sinusitis.
Sinusitis
Differential diagnosis ?
Differential diagnosis – Allergic rhinitis and nasal foreign body
Sinusitis
Treatment?
Treatment
Involvement of the Ear, Nose and Throat surgeon
Antibiotics – amoxicillin, amoxicillin-clavulanate, cefuroxime, cefpodoxime, azithromycin, clarithromycin, trimethoprim-sulfamethoxazole
Frontal sinusitis- parenteral ceftriaxone
Sinusitis
Complications ?
Complications
-periorbital cellulitis
Orbital cellulitis
Epidural abscess
Brain abscess
Meningitis
Cavernous sinus thrombosis
Osteomyelitis of the frontal bone(Pott puffy tumor)
Sinusitis
Prevention ?
Prevention- as for common cold
Acute pharyngitis/Acute pharyngotonsillitis
Etiology?
Etiology - bacterial, viral and fungal infections
May accompany a common cold or influenza.
Viruses -Type A coxsackieviruses, adenovirus and herpes simplex virus
Epstein-Barr virus and cytomegalovirus infections can manifest with pharyngitis
Bacteria -Group A beta-hemolytic streptococcus is the most important bacterial agent associated with acute pharyngitis and tonsillitis
Others - Corynebacterium diphtheriae, Corynebacterium haemolyticum, Neisseria gonorrhoeae, and Chlamydia trachomatis, Chlamydia pneumoniae, Mycoplasma pneumoniae and Mycoplasma hominis.
Fungi - Candida albicans
Acute pharyngitis/Acute pharyngotonsillitis
Clinical Features?
Clinical features- Red, sore, or “scratchy” throat. Membranes may cover the tonsils and tonsillar pillars. Vesicles or ulcers may also be seen on the pharyngeal walls. usually bacterial, if there’s whitish spots on the tonsils
Fever, painful swallowing, malaise, myalgia, headache, vomiting and abdominal pain
Viral origin- rhinorrhoea, cough and diarrhoea
Anterior cervical lymphadenopathy is common in bacterial pharyngitis.
Acute pharyngitis/Acute pharyngotonsillitis
Diagnosis?
Diagnosis - Throat culture to identify cases that are due to group A beta-hemolytic streptococci.
The various forms of pharyngitis cannot be distinguished on clinical grounds.
Other tests -Serologic studies, Rapid diagnostic tests with fluorescent antibody or latex agglutination to identify group A streptococci from pharyngeal swabs.
Gene probe and polymerase chain reaction can be used to detect unusual organisms such as M pneumoniae, chlamydia or viruses but these procedures are not routine diagnostic methods.
Acute pharyngitis/Acute pharyngotonsillitis
Treatment ?
Treatment –Depends on the aetiology,
viral pharyngitis – symptomatic, herpes simplex virus infection –acyclovir
Antibiotics - Penicillin is the therapy of choice for streptococcal pharyngitis. Alternatives- amoxicillin and macrolides
Mycoplasma and chlamydial – Macrolides and tetracyclines
Symptomatic treatment- antipyretics, warm salt water gargle
Acute pharyngitis/Acute pharyngotonsillitis
Complications? (suppurative and non-suppurative)
Complications
Suppurative complications
-middle ear infections
Parapharyngeal abscess
Retropharyngeal abscess
Peritonsillar abscess
Mastoiditis
Sinusitis
Non suppurative complications
Acute rheumatic fever
Post infectious glomerulonephritis
Syndenham chorea
Reactive arthritis
Acute epiglottitis
Aetiology ? immunocompromised and non-infectious causes
Aetiology - Hemophilus influenzae type B (Hib) [most common], group A b-hemolytic Streptococci etc
Immunocompromised- Pseudomonas spp, Candida, Mycobacterium tuberculosis
Noninfectious - trauma by foreign objects, inhalation and chemical burns, reactions to chemotherapy
Acute epiglottitis
Clinical features?
Clinical features- high fever, severe sore throat, drooling and difficulty in swallowing with the sitting up, mouth open and leaning forward position in order to enhance airflow (tripod position)
Difficulty in breathing and stridor
-Toxic, restless, air-hunger, cyanosis, coma
Acute epiglottitis
Diagnosis?
Diagnosis
laryngoscopy- large, cherry red swollen epiglottis. This should be done at operating room or intensive care unit
Avoid anxiety provoking procedures- phlebotomy, throat examination
a “thumb-sign” present in 79% of the cases on lateral X-rays of the neck
Ultrasonography
Acute epiglottitis
Mnagement?
Management
-it is a medical emergency
Secure airway-Tracheal intubation
Continuous administration of humidified oxygen
ENT surgeon and anaesthesiologist must be involved
-Nutrition/Hydration
-Antibiotics – amoxicillin clavulanate, cephalosporins (ceftriaxone,cefuroxime, cefotaxime) ampicillin/sulbactam, chloramphenicol
Acute epiglottitis
Complications?
Complications
Retropharyngeal abscess
Peritonsilar abscess
Bacterial tracheitis
Epiglottic abscess
Sepsis
Meningitis
Acute Laryngotracheobronchitis (Croup)
occurance?
It affects boys more than girls and more in children between 6 months and 3 years of age.
Acute Laryngotracheobronchitis (Croup)
Aetiology?
Aetiology-most viral-Human parainfluenza virus (types 1 and 3)
- others - influenza A and B viruses, respiratory syncytial virus, rhinovirus, coronavirus, human metapneumovirus and adenovirus
Acute Laryngotracheobronchitis (Croup)
Clinical features?
Clinical features- frequently preceded by 24–72 hours of nonspecific cough, rhinorrhea, coryza and fever, with abrupt onset of barky cough, hoarse voice and, often, inspiratory stridor during the night
Cyanosis, tachypnoea and tachycardia
Symptoms often resolves within 3-7 days
Acute Laryngotracheobronchitis (Croup)
Diagnosis?
Diagnosis- Clinical
-X-ray of the neck(PA view)- subglottic narrowing( steeple sign) pencil tip sign
Acute Laryngotracheobronchitis (Croup)
Treatment?
Treatment – make the child calm, administer oxygen, oral dexamethasone, nebulized epinephrine, nebulized budesonide, supportive care( fluids, close observation)
Acute Laryngotracheobronchitis (Croup)
differential diagonosis?
Differential diagnosis
-foreign body aspiration
-Angioneurotic oedema
Bacterial tracheitis
Peritonsilar abscess
Bacterial tracheitis
Aetiology?
Aetiology- Staphylococcus aureus(common) others- Moraxella catarrhalis, non-typable H. influenzae and anaerobic organisms
It often follows a viral respiratory infection (especially laryngotracheitis).
Bacterial tracheitis
Clinical features?
Clinical features: Barky cough, fever, respiratory distress may occur immediately or after a few days of apparent improvement.
The patient can lie flat, does not drool, and does not have the dysphagia associated with epiglottitis.
Bacterial tracheitis
diagnosis?
Diagnosis-Clinical
Lateral neck x-rays, direct laryngoscopy
Bacterial tracheitis
Treatment?
Treatment- Antibiotics(antistaphylococcal)
an artificial airway should be strongly considered.
Supplemental oxygen may be necessary
Bacterial tracheitis
Differential diagnosis?
Differential diagnosis
- Laryngotracheobronchitis
- Epiglottitis
Bacterial tracheitis
Complications?
Complications-
- Cardiorespiratory arrest
- Staphylococcal toxic shock syndrome
