Tonsillopharyngitis - Acute Disease Background

Introduction

Acute tonsillopharyngitis is an acute infection of the pharynx, palatine tonsils, or both. It is also called strep throat, acute tonsillitis, pharyngitis or adenotonsillitis.

Epidemiology

Acute pharyngitis or acute tonsillopharyngitis is one of the most common conditions physicians encounter, accounting for 1-2% of all ambulatory care visits. In the United States (US) alone, around 12 million visits are made in the outpatient clinic due to sore throat. The incidence of acute tonsillopharyngitis peaks in childhood and adolescence, with approximately 50% of cases occurring before the age of 18. In children, pharyngitis accounts for as much as 10% of visits to outpatient clinics. In adults, most cases occur by age 40; the incidence declines thereafter. Though the disease is more common in winter and early spring, the disease can occur at any time during the year.  

The epidemiology of acute tonsillitis or sore throat in Malaysia has not been well studied and documented. However, based on various hospital-based studies, acute respiratory infections (ARIs) were responsible for 39.3-44.1% of all pediatric admissions. Without doubt, upper respiratory tract infection (URTI) is the most common reason for seeking treatment in general practice and the hospital outpatient departments.

Pathophysiology

Acute tonsillopharyngitis spreads through person-to-person contact, usually through saliva or nasal secretions from an infected person. The primary reservoir of group A Streptococcus are humans. It is easily transmitted in schools, day care centers, and military training facilities. Transmission via food is rare, and if transmission happens, it is most likely due to the improper handling of food. Pets and the use of household items such as plates or toys cannot transmit the disease. Symptoms develop after a short incubation period of 24-72 hours.    

Acute tonsillopharyngitis may involve any part of the Waldeyer’s ring separately (the pharyngeal tonsils [adenoids], palatine tonsils, tubal and/or lingual tonsil) or all the components of the ring. Pathologically, acute tonsillitis takes the form of an exudative inflammation that is associated with antigenic stimulation of the tonsillar lymphoid parenchyma. In turn, antigenic stimulation leads to tonsillar hypertrophy causing clinical symptomatology.

Etiology

Viral  

Viruses are the main cause of acute tonsillopharyngitis. Double-stranded DNA viruses (eg human adenovirus, Epstein-Barr virus), single-stranded RNA viruses (eg influenza, para-influenza, rhinovirus, enterovirus, Coxsackie virus, coronaviruses, respiratory syncytial virus [RSV], human meta-pneumo-virus), and retroviruses (human immunodeficiency virus [HIV]) are among the viral causes.  

Bacterial  

Bacteria are responsible for about 5-15% of clinic consultations for acute sore throat in adults. They are most commonly caused by Gram-positive cocci known as Streptococcus pyogenes. This organism exhibits beta-hemolysis on blood agar plates and belongs to the group A Lancefield classification system for beta-hemolytic strep infection. Other bacterial causes include group C and G Streptococci, Staphylococcus aureus, Haemophilus influenzae, Nocardia, Corynebacteria, and Neisseria gonorrhoeae.

Risk Factors

Acute tonsillopharyngitis commonly infects children aged 5-15 years old and rare in <3 years old. Parents of school-aged children and other adults who are in close contact with infected individuals are also at risk. Another risk factor is crowded places (eg day care centers, schools, military barracks).