Herpes labialis

Herpes labialis, also called oral herpes or cold sore, is an infection caused by herpes simplex virus type 1. It causes painful blisters which recur and spontaneously heal. Early use of topical acyclovir can improve the symptoms, but it must be started as early as possible.

Herpangina

Herpangina is an infection caused by Coxsackie A virus. It's most common in children, and causes fever, odynophagia, and vesicles in the oral cavity. It spontaneously resolves after 3-4 days and only requires symptomatic treatment.

Oral candidiasis

Oral candidiasis or thrush is a fungal infection of the Candida species and affects the mucus membrane of the mouth. It may affect healthy people but more commonly affect those who are immunosuppressed. It causes a white plaque in the oral cavity or on the tongue. The plaque can be scraped off, unlike the plaque of leukoplakia. It may cause a cottony feeling in the mouth and loss of taste. Treatment is with oral an antifungal.

Tonsillitis

Tonsillitis, infection of the palatine tonsils, is a common condition in children and adults. There is no clear distinction between tonsillitis and pharyngitis, and so the condition may also be called pharyngitis or tonsillopharyngitis.

In 70% of cases tonsillitis is caused by viruses and is one part of a viral upper respiratory tract infection, which affects multiple parts of the upper respiratory tract. In 30% of cases, mostly in children, tonsillitis is isolated and bacterial, caused by streptococcus pyogenes, also called group A streptococcus (GAS). This is called streptococcal pharyngitis or strep throat. When a patient presents with symptoms of pharyngitis or tonsillitis it's important to determine whether it's viral or streptococcal. Both are self-limiting, but antibiotic treatment for streptococcal infection shorten the disease and prevent potentially severe complications.

Etiology

70% of cases are viral, caused by a respiratory tract virus like rhinovirus, adenovirus, influenzavirus, etc. Most of the remaining cases are caused by streptococcus pyogenes. Tonsillitis is also a part of mononucleosis, in which case it's caused by EBV.

Other rare causes of tonsillitis include:

Clinical features

Tonsillitis causes pain on swallowing which may radiate to the ear. The clinical features of viral and streptococcal tonsillitis are slightly different:


Features more commonly seen in viral infection	Features more commonly seen in streptococcal infection
Symptoms of infection of other parts of the upper respiratory tract, like rhinitis, conjunctivits, cough, hoarseness	Absence of cough
No fever or just a slight fever	Fever >38.5
Enlarged tonsils without coating	Enlarged tonsils with white coating
Visible erythema of the oropharynx	Absence of erythema of the oropharynx
No or just slightly tender cervical lymph nodes	Enlarged and tender cervical lymph nodes

Diagnosis and evaluation

The diagnosis of tonsillitis is clinical. The distinction between viral and streptococcal etiology can often also be made clinically with the use of the Centor criteria. One point is awarded for each criterium:

Absence of cough
Fever >38.5
Enlarged tonsils with white coating
Enlarged and tender cervical lymph nodes

When 4/4 criteria are positive, the pre-test probability of streptococcus is more than 50%, and a test isn't necessary. When 0-1/4 criteria are positive, the probability is low and testing isn't necessary. When the criteria are 2 or 3, the pre-test probability is intermediate, and so a test is recommended.

Testing is usually by point-of-care rapid tests which have high sensitivity and specificity. It can also be achieved by PCR or culturing, but this is rarely necessary.

Taking a blood test is usually unneccessary, but can be useful if there is doubt whether the infection is viral or bacterial. Inflammatory markers are usually more elevated in case of bacterial infection, and so a CRP > 75 or leukocyte count of > 15 points to streptococcus.

Management

For viral pharyngitis, no specific treatment exists. Symptomatic treatment involves paracetamol and local anaesthetic-containing lozenges.

For streptococcal pharyngitis, antibiotics are indicated. Streptococcus pyogenes is sensitive to penicillin, and so oral penicillin V is the first choice.

Complications

Streptococcal pharyngitis may (rarely), especially if untreated, lead to severe complications, including peritonsillar abscess, parapharyngeal abscess, scarlet fever, rheumatic fever, poststreptococcal glomerulonephritis. PANDAS is a very rare condition which may be caused by GAS infection, characterised by acute onset OCD and tics.

Scarlet fever

Scarlet fever, also called scarlatina, is a bacterial infection caused by streptococcus pyogenes (also called group A streptococci or GAS) characterised by streptococcal tonsillitis, fever, a "strawberry tongue", and a rash.

Clinical features

In addition to features of tonsillitis, a rash and "strawberry tongue" are present.

The rash usually begins 1-2 days after the tonsillitis. It's a generalised maculopapular exanthema which usually begins on the trunk and spreads from there. It's usually sandpaper-like, often easier to palpate than to see. The face is often flaming red, with notable sparing periorally. After 1-2 weeks desquamation occurs, especially on the hands and feet.

The tongue initially gets a white coating, and the papillae undergo hypertrophy, giving a strawberry appearance. Later, the white coating sheds, leaving the tongue red.

Management

Treatment is oral penicillin, same as for streptococcal tonsillitis.

Peritonsillar abscess

Peritonsillar abscess, an abscess localised around the palatine tonsil, is a potentially severe complication of bacterial tonsillitis. It's a rare condition, most commonly affecting people 20 - 40 years. Unlike the original bacterial tonsillitis is peritonsillar abscess usually a polymicrobial infection with anaerobes.

Clinical features

Clinical features include those of tonsillitis but also throat pain on the affected side, globus sensation in the neck, voice changes, and a visible swelling around the tonsil which pushes the tonsil medially. Eventually, trismus develops. The person is usually more ill than with a simple tonsillitis. Because swallowing becomes more and more difficult, drooling occurs.

Diagnosis and evaluation

The diagnosis can often be made clinically, but imaging may be used to visualise the extent if necessary.

Management

Treatment is by aspiration/incision and drainage of the contents, plus antibiotic therapy. With proper therapy, the prognosis is good.

Diphtheria

Diphtheria is an infection caused by corynebacterium diphtheriae. The bacterium most commonly infects the upper airways, but can also affect the lower airways, causing croup. Because the widely available dTP vaccine protects against diphtheria, it's very rare in countries with good vaccination coverage.

Clinical features

The bacterium forms a dense, grey pseudomembrane which covers the tonsils. If its severe enough, it can extend to cover the entire tracheobronchial tree. This causes symptoms of tonsillitis and fever. The bacterium also releases diphtheria toxins, which can result in myocarditis or neuropathy.

If the bacterium infects the lower airways (in which case it's called croup), it may cause severe airway obstruction with stridor and cyanosis because the pseudomembrane covers the airways.

Management

Treatment involves a horse-serum-derived antitoxin, antibiotic therapy, and vaccination. If the pseudomembranes cover and obstruct the lower airways, they must be removed by laryngoscopy.