Viral Rhinitis, Influenza, Rhinosinusitis and Pharyngitis.pdf

3/14/24, 1:37 AM Viral Rhinitis, Influenza, Rhinosinusitis and Pharyngitis Viral Rhinitis, Influenza, Rhinosinusitis and Pharyngitis Daniel J.G. Thirion, BPharm, MSc, PharmD, FCSHP Date of Revision: May 1, 2018 Peer Review Date: March 1, 2018 Introduction Upper respiratory tract infections (URTIs) a...

3/14/24, 1:37 AM Viral Rhinitis, Influenza, Rhinosinusitis and Pharyngitis Viral Rhinitis, Influenza, Rhinosinusitis and Pharyngitis Daniel J.G. Thirion, BPharm, MSc, PharmD, FCSHP Date of Revision: May 1, 2018 Peer Review Date: March 1, 2018 Introduction Upper respiratory tract infections (URTIs) are a group of diseases of the upper airway caused by many different viruses or bacteria. Each infection shares some common symptoms, involving, to variable degrees, sneezing, nasal congestion and discharge (rhinorrhea), sore throat, cough, low-grade fever, headache, and malaise. This chapter describes each infection and its symptomatic management. Pathophysiology Viral Rhinitis (Common Cold) The common cold is a viral infection caused by more than 200 different viruses. Among these, rhinoviruses (30– 50%) are the most common in all age groups. More than 100 serotypes of rhinovirus have been identified. Coronaviruses are also frequently involved, accounting for 10–20% of infections. Other common viruses are respiratory syncytial virus (RSV), adenovirus, parainfluenza and enterovirus.​ ​ ​ The common cold is one of the most common infectious diseases of humankind. Preschool children average 6 episodes annually and adults 2–3.​ Daycare attendance is an important risk factor for children.​ It is estimated that 40% of time lost from work and 30% of absences from school are due to the common cold.​ ​ ​ It can occur at any time of year but is less common during the summer months. Rhinoviruses are more prevalent during fall and spring, and coronaviruses during mid-winter and early spring.​ The transmission of viruses that cause upper respiratory tract infection can occur by any of the following 3 mechanisms:​ Hand contact with secretions that contain the virus, either directly from an infected person or indirectly from environmental surfaces Small-particle aerosols lingering in the air Direct inhalation of large-particle aerosols from an infected person All 3 mechanisms are possible for each virus but the primary routes of transmission may differ between them. Hand-to-hand contact appears to be the major transmission route for rhinovirus infection. Contact between the virus and nasal mucosa appears to be important for initiation of the infection. The increase in vascular permeability, glandular secretion and vasodilatation that follows are responsible for the symptoms.​ ​ The detailed mechanisms by which viral infection causes such changes in the nasal mucosa are still incompletely understood.​ The host's humoral and cellular immune responses seem to play pivotal roles. Cholinergic stimulation leads to increased mucous gland secretion and sneezing. No increase in histamine concentration is noted.​ Viral replication peaks in 48 hours but viral shedding can continue for up to 3 weeks.​ The common cold is characterized by a sore throat usually resolving within a few days, followed by nasal congestion, rhinorrhea, sneezing and cough. Nasal discharge can sometimes be purulent and mistaken for bacterial sinus infection.​ Fever is infrequent in adults but common in children.​ Symptoms peak around day 2–4 and begin to resolve by day 7. For a small proportion of patients, symptoms such as cough can still be present after 3 weeks. https://cps-pharmacists-ca.login.ezproxy.library.ualberta.ca/print/new/documents/MA_CHAPTER/en/v_rhinitis_flu_sinusitis_pharyngitis 1/19 3/14/24, 1:37 AM Viral Rhinitis, Influenza, Rhinosinusitis and Pharyngitis The common cold is usually a self-limiting illness confined to the upper respiratory tract.​ It can sometimes predispose individuals to bacterial complications, such as otitis media (especially in children via dysfunction of the eustachian tube​), bacterial rhinosinusitis and pneumonia. It may also cause exacerbations of asthma.​ Influenza Influenza in humans is caused by influenza A and/or B virus. Influenza A viruses are categorized into subtypes on the basis of 2 surface antigens: hemagglutinin and neuraminidase. Influenza B viruses are separated into 2 distinct genetic lineages but are not categorized into subtypes.​ Immunity to 1 subtype does not confer protection against another subtype, and mutations occur often.​ Although influenza A is more common and tends to cause more severe illness, it is impossible to differentiate clinically between influenza A and B.​ ​ Influenza is normally seen between November and April in the northern hemisphere. Debate exists as to how influenza virus is transmitted: airborne, droplet, contact or a combination of these.​ The incubation period for influenza virus averages 2 days.​ Viral replication occurs in the superficial epithelium of the airway tract. Symptoms, usually having an abrupt onset, are related to the presence of the virus in the airway or to the host immune response. Initial symptoms tend to be systemic in nature, with respiratory symptoms becoming prominent as systemic symptoms subside.​ Common systemic symptoms include fever, myalgia, headache, malaise and chills. Respiratory symptoms include sore throat, nonproductive cough and rhinitis.​ The infectivity period starts before the onset of symptoms and usually lasts 5–7 days, but shedding of the virus may continue for 7 days or longer after the start of symptomatic illness, especially in children and immunocompromised patients.​ Complications of influenza include pneumonia and even death. Influenza may worsen chronic obstructive pulmonary disease, asthma and pulmonary conditions of patients with cystic fibrosis. In 2011, influenza and pneumonia together were responsible for 5767 deaths and ranked 8​th among leading causes of death in Canada.​ Persons at high risk of experiencing complications due to influenza are described in Assessment of Patients with Upper Respiratory Tract Symptoms, Table 1. For more information, consult the Compendium of Therapeutic Choices: Influenza. Rhinosinusitis Acute rhinosinusitis is characterized by inflammation of the nasal cavity and paranasal sinuses in response to infection, that lasts less than 4 weeks.​ ​ Symptoms include nasal congestion and obstruction, purulent nasal discharge, maxillary tooth discomfort and facial pain or pressure, hyposmia or anosmia, cough, headache, fever, and malaise.​ Rhinosinusitis is often preceded by a viral upper respiratory tract infection. Viral and bacterial infections, as well as allergic rhinitis, affect mucociliary transport thereby disrupting evacuation of microorganisms. Although it is often preceded by a viral upper respiratory tract infection, only 0.5–2% of episodes of viral rhinosinusitis are complicated by acute bacterial infection.​ The most common viruses are rhinovirus, influenza virus and parainfluenza virus. Streptococcus pneumoniae or Haemophilus influenzae cause 70% of bacterial rhinosinusitis.​ Moraxella catarrhalis is also a common pathogen in children.​​ Other events that introduce microorganisms into the sinuses (such as dental extraction) or anatomical abnormality may also be precipitants. Complications of acute rhinosinusitis include periorbital and orbital cellulitis, orbital abscess, blindness and cavernous sinus thrombosis.​ Complications of chronic rhinosinusitis can include mucoceles (airless, expanded sinuses) and nasal polyps.​ Rhinosinusitis is considered chronic if symptoms persist for more than 3 months. Risk factors for developing chronic rhinosinusitis include anatomical abnormalities (e.g., deviation of the nasal septum, septal spurs, hypertrophic turbinates, nasal polyps), conditions that affect the normal function of the mucociliary sinus epithelium (e.g., cystic fibrosis), and conditions that affect the normal immune defenses of the upper respiratory tract. Sixty percent of chronic rhinosinusitis is caused by H. influenzae. Other responsible organisms are Staphylococcus aureus, alphahemolytic streptococci, Bacteroides species, Veillonella species, Corynebacterium species, Pseudomonas https://cps-pharmacists-ca.login.ezproxy.library.ualberta.ca/print/new/documents/MA_CHAPTER/en/v_rhinitis_flu_sinusitis_pharyngitis 2/19 3/14/24, 1:37 AM Viral Rhinitis, Influenza, Rhinosinusitis and Pharyngitis aeruginosa (patients with nasal polyps or cystic fibrosis) and fungi (diabetic or immunocompromised patients).​​ Pharyngitis Acute pharyngitis is an inflammatory syndrome of the pharynx. Many bacterial and viral organisms are capable of inducing pharyngitis, but the majority (90%) are viral.​ Pharyngitis may be present in Epstein-Barr virus, influenza, the common cold, measles, varicella, allergic rhinitis, and rhinosinusitis, or may be due to exposure to irritating substances or environmental pollutants, ingestion of caustic substances or direct trauma to the pharynx. Among bacterial causes, group A beta-hemolytic streptococcus (GABHS) is by far the most commonly implicated (15–30% of cases in children 5–15 years of age and 5–10% in adults).​ Pharyngitis due to GABHS is usually seen during the winter and early spring. Impetigo, suppurative complications (peritonsillar or retropharyngeal abscess, cervical lymphadenitis, mastoiditis, and rhinosinusitis), rheumatic fever and post-streptococcal glomerulonephritis may occur secondary to bacterial pharyngitis.​ Rheumatic fever is prevented by treatment of GABHS within 9 days of onset of the infection.​ Goals of Therapy Alleviate symptoms Eradicate infection or shorten duration of infection Prevent complications of infection Patient Assessment Determine symptoms, duration and risk factors for serious disease. See Figure 1 and Table 2 in Assessment of Patients with Upper Respiratory Tract Symptoms for an assessment algorithm and summary of the differentiating characteristics of upper respiratory tract disorders. Viral Rhinitis Viral rhinitis is a self-limiting disease that rarely causes complications. Currently, no therapy is available to change the course of disease. Management is targeted at alleviating symptoms rather than treating the infection. Influenza Typical symptoms include fever/chills, myalgia, headache, nonproductive cough and fatigue. GI symptoms (e.g., nausea, vomiting, diarrhea) are generally uncommon in adults but more common in children. GI symptoms may occur in up to 30% of cases depending on the infecting strain.​ ​ Persons at risk of complications (see Assessment of Patients with Upper Respiratory Tract Symptoms, Table 1) require immediate assessment of the need for antiviral therapy.​ Rhinosinusitis Most cases of rhinosinusitis are viral and are self-limiting. Differentiating bacterial from viral rhinosinusitis is a challenge because the clinical features of the 2 etiologies are similar.​ A change in the colour of the nasal discharge is not a specific sign of bacterial infection since mucopurulent nasal secretions may also occur a few days after onset of a viral infection.​ Bacterial rhinosinusitis is suggested when sinus symptoms do not improve https://cps-pharmacists-ca.login.ezproxy.library.ualberta.ca/print/new/documents/MA_CHAPTER/en/v_rhinitis_flu_sinusitis_pharyngitis 3/19 3/14/24, 1:37 AM Viral Rhinitis, Influenza, Rhinosinusitis and Pharyngitis within 10 days or worsen after 5–7 days, and by the presence of nasal obstruction or purulence plus one or both of facial pain/pressure/fullness or hyposmia/anosmia;​ ​ these patients should be assessed for antibiotic therapy. Other symptoms (e.g., headache, dental pain, cough, halitosis) may be present but are not used for the diagnosis of acute bacterial rhinosinusitis. Pharyngitis A sore throat is common to many URTIs and usually does not require specific treatment. Symptoms suggestive of GABHS include sore throat with a sudden onset, fever and headache. Nasal congestion, conjunctivitis and cough are not generally suggestive of bacterial pharyngitis.​ After eliminating other causes of sore throat, a modified Centor score can be used to help determine the likelihood of GABHS and therefore the need for antibiotic treatment.​ ​ The score is determined using the criteria listed in Table 1. If the cumulative score is ≥2 points, refer the patient for culture and possibly antibiotics. The score is not a diagnostic tool and should not be relied upon as such. As many as 25–30% of all GABHS-positive culture results in adults with pharyngitis occur in those with a modified Centor score of 38°C 1 Absence of cough 1 Swollen, tender anterior cervical nodes 1 Tonsillar swelling or exudate 1 Age 3–14 y 1 15–44 y 0 ≥45 y -1 Adapted with permission from McIsaac WJ, White D, Tannenbaum D, Low DE. A clinical score to reduce unnecessary antibiotic use in patients with sore throat. CMAJ 1998;158:75-83. Copyright © 1998 Canadian Medical Association. Prevention Upper respiratory tract viruses are transmitted by direct contact (hand-to-hand), aerosol particles or contact with settled droplets. Routine handwashing is recommended to prevent transmission of infection.​ ​ One should also try not to touch the face and eyes. Proper handwashing technique is described in Common Cold and Influenza—What You Need to Know at the conclusion of this chapter. Alcohol-based hand sanitizers are widely used in health-care settings or in situations when water is not available; however, they may be of limited value for preventing spread of respiratory infections.​ ​ Handwashing remains the first and most important step for cleaning hands, especially if they are https://cps-pharmacists-ca.login.ezproxy.library.ualberta.ca/print/new/documents/MA_CHAPTER/en/v_rhinitis_flu_sinusitis_pharyngitis 4/19 3/14/24, 1:37 AM Viral Rhinitis, Influenza, Rhinosinusitis and Pharyngitis visibly soiled. Hand sanitizers are to be used as a supplement to regular, effective handwashing when water is not readily available and when hands are not visibly soiled. Sneeze and cough etiquette is another method traditionally advised for the prevention of URTIs. This involves coughing or sneezing into an arm, sleeve or tissue. If a tissue is used, it should be promptly thrown away and the hands washed.​ Prevention of Influenza Annual influenza vaccination is the most effective way to prevent influenza and its complications. Health Canada has approved trivalent and quadrivalent vaccines, most of which are inactivated, but 1 live attenuated quadrivalent influenza vaccine is available. Refer to the current statement from the National Advisory Committee on Immunization (NACI) for details regarding yearly vaccine availability.​ The vaccines are modified each year according to the viruses expected to circulate in the population that season. The efficacy of the vaccine depends on the degree of antigenic match between the vaccine virus and the circulating virus. Influenza vaccine can provide moderate protection against influenza, but protection is greatly reduced or absent in some seasons.​ Healthy school-age children and adults respond well to vaccination, whereas preschool children, the elderly and the immunocompromised respond less well.​ ​ ​ The live-attenuated influenza vaccine provides improved efficacy compared with inactivated vaccines in children ≤6 years of age but should be avoided in certain populations (those 59 years of age, pregnant women, those with immunodeficiencies or severe asthma, or children receiving ASA therapy).​ Based on clinical evidence, allergy to eggs is no longer considered to be a barrier to vaccination against influenza;​ however, similar to all vaccinations, emergency equipment should be readily available (consult the Compendium of Therapeutic Choices: Influenza for more information). With a good antigenic match, influenza vaccination prevents influenza in 56–91% of healthy children and adults; however, protection is lower in elderly and immunocompromised patients.​ Vaccination also reduces rates of illness, numbers of physician visits and sick days in healthy, working adults. Protection is generally achieved approximately 2 weeks after vaccine administration, and usually lasts