The oropharynx and Waldeyer tonsillar ring are normally colonized by many species of aerobic and anaerobic bacteria, including staphylococcus, nonhemolytic streptococci, lactobacillus, bacteroides, and actinomyces. These organisms, and other pathogenic bacteria, viruses, fungi, and parasites, can cause infections of tonsillar and adenoid tissue. Oropharyngeal cultures obtained during the infection are not always useful in distinguishing the offending pathogen as they often yield multiple organisms, reflecting the normal flora of the oral mucosa.
Acute pharyngotonsillitis may be caused by viral or bacterial infection, viral etiology being the most common. It is often difficult to distinguish between the two causes based on clinical exam. Patients present with fever, malaise, odynophagia, and lymphadenitis. On a physical exam tonsillar enlargement, erythema, and exudate may be present.
Roughly half of cases of acute pharyngotonsillitis have a viral etiology. Patients commonly present with complaints of sore throat and dysphagia. Upon examination, there is often fever, tender cervical lymphadenopathy, tonsillar inflammation, and erythema with possible exudate. Common viral pathogens include adenovirus, rhinovirus, reovirus, respiratory syncytial virus (RSV), influenza, and parainfluenza viruses. Treatment for most viral infections is generally supportive. In some cases, patients develop a bacterial superinfection of tonsils that results in more severe symptoms. These patients benefit from systemic antibiotics.
Tonsillar infections with the Coxsackie virus result in herpangina, which presents as ulcerative vesicles over the tonsils, posterior pharynx, and palate. The disease commonly occurs in children under the age of 16. Such patients present with generalized symptoms of headache, high fever, anorexia, and odynophagia.
Epstein–Barr Virus (EBV) belongs to the herpes family of viruses and causes acute pharyngitis as a part of infectious mononucleosis. In developed nations and regions of high socioeconomic status, primary infection by EBV occurs during the second and the third decade of life. This is not the case in developing countries where more young children are affected by the disease. EBV is transmitted orally, and manifests as fever, generalized malaise, lymphadenopathy, hepatosplenomegaly, and pharyngitis. The tonsils are severely enlarged, sometimes to the point of compromising the airway, and are covered with an extensive grayish-white exudate. When the virus is acquired at a younger age, symptoms are often less severe.
EBV preferentially infects and transforms human B lymphocytes. The incubation period is about 2–6 weeks, during which EBV induces a proliferation of infected B cells. This is followed by a cellular immune response, characterized by the appearance of “atypical” cytotoxic T lymphocytes in the blood. In immunosuppressed patients with inherited or acquired immunodeficiency, such as AIDS, X-linked lymphoproliferative disorder, and post-transplant immunosuppression, this T-lymphocyte response is limited, and uncontrolled proliferation of B cells may result in hyperplasia of lymphoid tissues. EBV is also associated with Hodgkin and non-Hodgkin lymphomas, Burkett lymphoma, nasopharyngeal carcinoma, and other lymphoproliferative disorders.
Diagnosis of acute infectious mononucleosis usually can be made upon clinical observation of absolute lymphocytosis, atypical lymphocytes in the peripheral smear, heterophile antibodies, and EBV-specific antibodies. Increased fluid intake, rest, and analgesics comprise primary treatment. In the case of progressive airway obstruction due to obstructive tonsillar swelling, a short course of systemic steroids can also help. Rarely, a nasopharyngeal airway, nasotracheal intubation, tonsillectomy, or tracheotomy might be required to secure the airway.
An acute retroviral syndrome is a manifestation of primary infection with the human immunodeficiency virus (HIV). Following 1–5 week incubation period, symptoms develop that include fever, nonexudative pharyngitis, lymphadenopathy, and systemic symptoms such as arthralgia, myalgia, and lethargy.
Acute Streptococcal Pharyngotonsillitis
Group A beta-hemolytic streptococcus (GABHS) is the most common cause of acute bacterial pharyngotonsillitis in children. “Strep throat” is a very common disease among adolescents and children, with an incidence that peaks during the winter and spring months, and tends to be uncommon in children less than 3 years of age. Transmission generally occurs through droplet spread and the incubation period is about 2–5 days. Symptoms usually include fever, sore throat, cervical lymphadenopathy, dysphagia, and odynophagia. Physical examination typically reveals tonsillar and pharyngeal erythema with purulent exudate.
Throat culture with a blood agar plate (BAP) is the standard method for establishing the diagnosis of pharyngitis caused by group A streptococcus in children. Office-based rapid antigen-detection tests (RADT) are also available. These tests have excellent specificity; however, the sensitivity of these tests is lower when compared to BAP leading to recommendation to confirm negative RADT results with BAP culture. The definitive tests to determine GABHS infection is measuring serum titers of antistreptolysin O (ASO). Certain individuals, “carriers,” have positive throat cultures and remain asymptomatic.
Early diagnosis of GABHS pharyngitis and appropriate antimicrobial treatment is a standard of care to primarily prevent rheumatic fever. Although a number of drugs have shown promise in treating GABHS, a 10-day course of Penicillin V remains the treatment regimen of choice. Amoxicillin is commonly substituted for penicillin. Intramuscular benzathine penicillin G given as one dose is also an effective treatment and can be used when compliance with oral regimen is a concern. First-generation cephalosporins, macrolides, and climdamycin are alternatives for treatment of patients allergic to penicillin.
Complications of GABHS Infection
Most GABHS pharyngotonsillitis is benign and self-limited; however, the potential for nonsuppurative and suppurative complications exists. The emphasis on rapid diagnosis and the widespread use of antibiotics have markedly decreased the incidence of nonsuppurative complications. In contrast, suppurative complications of acute bacterial tonsillitis are still commonly encountered.
Scarlet fever occurs secondary to the endotoxin production by the bacteria during the episode of acute streptococcal pharyngotonsillitis. Clinical presentation includes erythematous rash, fever, lymphadenopathy, dysphagia, and erythematous tonsils and pharynx covered with a yellow membranous film. The tongue may become red, with desquamation of the papillae, often described as “strawberry tongue.”
Acute rheumatic fever usually occurs 1–4 weeks following pharyngotonsillitis caused by GABHS. Streptococcal infection results in production of cross-reactive antibodies to heart muscle, leading to subsequent endocarditis, myocarditis, or pericarditis. Once heart tissue damage occurs, little can be done to reverse the process.
Poststreptococcal glomerulonephritis typically occurs as an acute nephritic syndrome about 1–2 weeks after a pharyngotonsillar infection or skin infection with a GABHS. The pathogenic mechanism of the disease involves injury to the glomerulus by deposition of the immune complexes as well as circulating autoantibodies.
A clinical entity known as pediatric autoimmune neuropsychiatric disorder associated with group A streptococcal infection (PANDAS) has been described. PANDAS is associated with the abrupt onset of severe exacerbations of obsessive–compulsive type behaviors or tics in children following GABHS infection. The pathophysiology of this condition is thought to be similar to Sydenham chorea, in which antineuronal antibodies cross-react with regions in the basal ganglia, producing behavioral and motor disturbances.
Suppurative complications of bacterial pharyngotonsillitis include peritonsillar abscess, parapharyngeal abscess, retropharyngeal abscess, and cervical lymphadenitis or abscess. Peritonsillar abscess forms as a result of the spread of infection from the superior pole of the tonsil into the potential space between the pharyngeal muscle bed and the tonsillar capsule. The abscess usually occurs unilaterally and patients present with severe pain, odynophagia, and dysphagia. Trismus is often present secondary to the inflammation of the pterygoid musculature. On examination there is unilateral swelling of the plate with the tonsil medially displaced and the uvula shifted to the opposite side. Needle aspiration and incision and drainage are usually performed to treat the abscess. In patients with recurrent tonsillitis and recurrent peritonsillar abscess, a tonsillectomy is often recommended. Most surgeons prefer to operate after the acute infection has resolved; however, a “Quincy tonsillectomy,” which is a tonsillectomy in acutely infected patient, is occasionally performed.
Infection from the tonsil or from a peritonsillar abscess can spread through the superior constrictor muscle into a potential space between the superior constrictor muscle and the deep cervical fascia forming a parapharyngeal space abscess. The abscess leads to medial displacement of the tonsil and pharyngeal wall. The patients often present with trismus and a decrease in the neck's range of motion secondary to the inflammation of adjacent pterygoid and paraspinal muscles. If not treated, the abscess may spread down the carotid sheath and into the mediastinum.
A retropharyngeal abscess may result from a spread of peritonsillar abscess or from infection of the lymph nodes in the retropharyngeal space. It is more common in children and symptoms usually include fever, dysphagia, muffled speech, noisy breathing, neck stiffness, and cervical lymphadenopathy.
Pharyngotonsillitis can lead to the enlargement and infection of the corresponding draining lymph nodes. Patients may present with enlarged, warm, erythematous, tender lymph nodes that can then progress to suppuration and abscess formation.
Non–Group a Streptococcal Pharyngitis
Group C and G streptococci commonly colonize upper respiratory tract and have been responsible for food-borne and waterborne outbreaks of pharyngitis. The symptoms can be similar to group A streptococcal pharyngitis but are generally less severe. Non–group A streptococci have never been shown to cause acute rheumatic fever.
Pharyngeal diphtheria is now extremely rare due to the widespread use of childhood immunization. The infection is caused by Corynebacterium diphtheriae and primarily occurs in unimmunized individuals. In addition to the usual symptoms of acute pharyngitis, this disease is characterized by a grayish firmly adherent pseudomembrane that covers the tonsils and may extend to the nares, uvula, soft palate, and pharynx. The disease can spread to larynx and tracheobronchial tree potentially compromising the airway. Removal of the pseudomembrane reveals bleeding of underlying surface. Exotoxins produced by C. diphtheriae may produce cardiac toxicity and neurotoxicity. The diagnosis is confirmed by culture of the pseudomembrane in Loeffler's or tellurite selective medium. The treatment should be started immediately with administration of diphtheria antitoxin and penicillin or erythromycin, even before confirmation with the culture.
Patients with exposure to sexually transmitted diseases can develop tonsillar infections with Neisseria gonorrhoeae or Treponema pallidum. Gonococcal infections may present as an exudative pharyngitis. Primary oral syphilis manifests as a painless chancre on the lips, buccal mucosa, or oropharynx. Patients with secondary syphilis may present with bilateral tonsillar hypertrophy and painful oropharyngeal and tonsillar ulcers.
The role of anaerobic bacteria in tonsillitis should also be considered. Anaerobic bacteria predominate in tonsillar and retropharyngeal abscesses. There is also evidence of synergy between anaerobes and GABHS in cases of pharyngotonsillitis.
Oropharyngeal candidiasis is caused by overgrowth of Candida albicans and often present in patients with a history of immunosuppression, radiation, or altered microflora following long-term broad-spectrum antibiotic use. On exam, there are white cottage-cheese-like plaques over the pharyngeal mucosa, which bleed if removed with a tongue depressor. Clinical diagnosis may be confirmed with potassium hydroxide staining revealing fungal hyphae. Initial therapy usually consists of oral hygiene and topical treatment. Some of the available agents include oral nystatin preparations, amphotericis lozenges, and clotirimazole torches.
Recurrent Acute Tonsillitis
Many patients experience episodes of acute tonsillitis with complete recovery between episodes. The tonsils, because of their location and numerous crypts and crevices, harbor bacteria. Aggressive medical therapy for acute tonsillitis may not prevent additional infections. Otolaryngologists and primary care providers have debated the role of surgery for these patients for many years. Most surgeons now agree that a tonsillectomy is indicated in patients with recurrent acute tonsillitis involving 6–7 episodes of acute tonsillitis in 1 year, 5 episodes per year for 2 consecutive years, or 3 episodes per year for 3 consecutive years.
Chronic tonsillitis is diagnosed when a sore throat is present for at least 3 months and is associated with tonsillar inflammation, halitosis and persistent tender cervical adenopathy. Clinical examination is often unremarkable but may reveal decreased tonsillar crypts and a smooth tonsillar capsule.
Antibiotics effective against anaerobes and beta-lactamase producing organisms, such as clindamycin or amoxicillin clavulanate, can be used for treatment. In patients with chronic tonsillitis unresponsive to appropriate antimicrobial therapy that results in persistent foul taste, halitosis or recurrent tonsillitis associated with the GABHS carrier state, tonsillectomy would be indicated.
Tonsilloliths are microbial biofilms that form within tonsillar crypts and are associated with halitosis and chronic cryptic tonsillitis. Patients may present with a foreign body sensation in the throat and expressible, hard white masses on their tonsils. Complete or intracapsular tonsillectomy is a treatment option for chronic cryptic tonsillitis in adults.