Tonsillitis overview

# Overview
Tonsillitis is the infection and inflammation of the tonsils. It usually presents as sore throat accompanied by fever.

# Historical Perspective
Cornelius Caesus in A.D. 30 explained that tonsils are covered by a membrane and require to be separated and extracted by a process called tonsillectomy. This encyclopaedia was recovered in 1478 in Papal library, after being lost for 1400 years.

# Classification
The main types of tonsillitis are:
- Acute tonsillitis can be bacterial or viral
- Subacute tonsillitis mostly caused by a bacteria Actinomyces
- Chronic tonsillitis is due to allergies, asthma, GERD, viruses like EBV or bacterial
- Recurrent tonsillitis

# Pathophysiology
Tonsillitis develops when the pathogen, viral or bacterial, infects the tonsils and elicits an inflammatory response. It develops when the viruses infiltrate the tonsils and cause an inflammatory response of up-regulated cytokines. Bacterial tonsillitis considered acute is primarily caused by group A -hemolytic streptococcus (GABHS) streptococcus pyogenes infection. S. pyogenes and taxonomically-similar bacteria infiltrate the tonsillar epithelium, successfully penetrating the protective mucosal films in the oral and nasal cavity. Recurrent bacterial tonsillitis is caused primarily by Staphylococcus aureus. Following invasion, S. aureus is internalized by non-phagocytic cells through fibronectin-binding protein and beta-integrins. Invasion of non-eukaryotic cells results in the up-regulation of cytokines, resulting in tonsillitis. Tonsillitis is associated with conditions and diseases associated with its viral and bacterial pathogens.

# Causes
The most common causes of tonsillitis are adenovirus, rhinovirus, influenza, coronavirus, and respiratory syncytial virus. It can also be caused by Epstein-Barr virus, herpes simplex virus, cytomegalovirus, or HIV. The second most common causes are bacterial which may be caused by group A streptococcal bacteria, resulting in strep throat..  Sometimes, tonsillitis is caused by a superinfection of spirochaeta and treponema, in this case called Vincent's angina or Plaut-Vincent angina.

# Differentiating tonsillitis from other diseases
Tonsillitis must be differentiated from other diseases that present with edema and erythema of the tonsils and nasopharynx, lymphadenopathy, fever, dysphonia, and dysphagia.

# Epidemiology and Demographics
The epidemiology of tonsillitis is not completely known. A research indicates that 15-30% of sore throats in children and 5-10% sore throats in adults are bacterial tonsillitis. Research on Norwegian twins indicates a prevalence of approximately 11,700 per 100,000 individuals, while a study on primary school children in Turkey indicated recurrent tonsillitis prevalence of approximately 12,100 per 100,000 individuals. Acute tonsillitis from S. pyogenes primarily affects children between 5 and 15 years old. Tonsillitis is more common in females than males. There is no racial or demographic predisposition to tonsillitis. The case fatality rate is unknown.

# Risk Factors
Risk factors for tonsillitis involve increasing the risk of invasion by pathogenic viruses or bacteria, including environmental and systemic factors.

# Natural history, complications and prognosis
Acute tonsillitis will usually present with erythema and edema of the tonsils rapidly upon infiltration of the pathogen. It is usually self-limited and symptoms will be resolved within 3-4 days. Recurrent tonsillitis will usually not resolve itself and will require antimicrobrial therapy or tonsillectomy when indicated. Complications of tonsillitis are caused by persistence and/or spread of the responsible pathogen - usually bacterial. The prognosis for acute tonsillitis without treatment is usually good, while the prognosis for untreated recurrent tonsillitis will vary based on presence of life-threatening complications. With treatment, the prognosis of acute and recurrent tonsillitis is usually good.

# Diagnosis

## History and Symptoms
Symptoms of tonsillitis include a severe sore throat (which may be experienced as referred pain to the ears), painful/ difficult swallowing, headache, fever and chills, and change in voice causing a "hot potato" voice.
Common symptoms of tonsillitis include localized pain in the head, neck, and throat, as well as coughing, headache, and systemic symptoms including fever, chills, and swollen lymph nodes in the neck. Less common symptoms include nausea, vomiting, furry tongue, bad breath (halitosis), and difficulty opening your mouth.

## Physical Examination
Tonsillitis is mostly diagnosed clinically. Physical examination signs of tonsillitis include tonsillar erythema, edema, and exudate. Cervicular lymphadenopathy is present. along with fever and dysphonia. is characterized by signs of red, swollen tonsils which may have a purulent exudative coating of white patches (i.e. pus). In addition, there may be enlarged and tender neck cervical lymph nodes. Tonsillitis patients will usually present with malaise and lethargy, appearing ill, due to fever.

## Laboratory Findings
The diagnosis of GABHS tonsillitis is mostly clinical but it can be confirmed by culture. Samples are obtained by swabbing both tonsillar surfaces and the posterior pharyngeal wall are plated on sheep blood agar medium.  The isolation rate can be increased by incubating the cultures under anaerobic conditions and using selective media.

# Treatment

## Medical Therapy
The mainstay of therapy for tonsillitis includes antimicrobial therapy analgesics. Supportive therapy includes salt water gargles and lozenges. Antimicrobial therapy is usually penicillin, though alternative regimens include cephalosporins, clindamycin, azithromycin, clarithromycin, erythromycin, amoxicillin. Treatment of tonsillitis consists of pain management medications and lozenges. If the tonsillitis is caused by bacteria, then antibiotics are prescribed, with penicillin being most commonly used. Erythromycin is used for patients allergic to penicillin. In many cases of tonsillitis, the pain caused by the inflamed tonsils warrants the prescription of topical anesthetics for temporary relief. Viscous lidocaine solutions are often prescribed for this purpose. Ibuprofen or other analgesics can help to decrease the edema and inflammation, which will ease the pain and allow the patient to swallow liquids sooner. When tonsillitis is caused by a virus, the length of illness depends on which virus is involved. Usually, a complete recovery is made within one week; however, some rare infections may last for up to two weeks. Additionally, gargling with a solution of warm water and salt may reduce pain and swelling.

## Surgery
Chronic cases may indicate tonsillectomy (surgical removal of tonsils) as a choice for treatment.

# Prevention

## Primary Prevention
The most effective form of primary prevention consists of proper hygienic practices as well as avoiding individuals suffering from contagious infections that may result in tonsillitis.
- Hygienic practices may be defined as the following:
- Proper hand washing and hand antisepsis 
- Proper selection of hand hygiene antimicrobial agents
- Facial cleanliness
- Proper dental hygiene 
- Avoiding contact between hands, eyes, mouth, and infectious agents

## Secondary Prevention
Secondary prevention involves usage of antibiotics to prevent recurrence of tonsillitis.