An acute pharyngitis is usually a mild and self-limited disease caused in most cases by some virus - explain this to the patient also.
Group A streptococci rapid test is the primary option to be taken from patients with throat pain symptoms and Centor score ≥ 3 (see table T1). Alternatively (or if symptoms become prolonged), streptococcal culture or throat culture is taken.
Antimicrobials are indicated in infections caused by group A streptococci.
A peritonsillar abscess should be identified and treated as emergency.
In recurrent tonsillitis, tonsillectomy is considered if an antimicrobial trial does not help and there are acute infections at least 3 times within 6 months or 4 times within a year.
Epidemics should be recognized and their spread prevented by giving antimicrobial treatment also to asymptomatic carriers (even when caused by group C or G streptococci).
In the majority of cases, sore throat has a viral aetiology. Adenovirus is the most common causative virus. Viruses can also cause a clinical picture similar to a streptococcal disease with high fever, rash and pharyngeal exudate.
Group A streptococci cause 14% of all cases of tonsillitis in adults and 37% of all cases of tonsillitis in children.
A throat infection caused by group C or G streptococci resembles that caused by group A streptococci. These groups may also cause epidemics.
Adenovirus infections are common especially among children less than 5 years of age but they are found in all age groups.
Epstein-Barr virus (EBV) causes typical mononucleosis in adolescents, but similar clinical picture is also seen in small children. In other age groups the symptoms are usually mild.
Besides infections caused by group A streptococci, specific diagnosis should be pursued in rare bacterial throat infections caused by gonococci Gonorrhoea and diphtheria Diphtheria.
Of the viral infections, mononucleosis Mononucleosis should be recognized because of the prolonged clinical course and the potential complications.
Mycoplasma and chlamydia infections rarely present with sore throat only, and need not be searched for.
Examination of the patient
Examination of the pharynx
Inspection: erythema, peritonsillar oedema, opening of the mouth, air space
Palpation if needed (e.g. using a wooden spatula): in peritonsillar abscess the peritonsillar space is swollen, tender and taut
Palpation of the neck
Prominent lymph nodes, possibly also in other locations than the jaw angle; mononucleosis?
By looking into the pharynx, infection caused by a virus cannot be told apart from bacterial tonsillitis; for example, coating on the tonsils can be found in both.
Use an appropriate sterile cotton-tipped swab to obtain the sample.
Press the tongue firmly with a wooden spatula and use a good focused light (a headlamp).
Take the sample from both tonsils and the posterior pharyngeal wall by pressing the cotton tip firmly against the mucosa and making circular movements. Avoid touching the lips or the tongue with the swab.
Usually the result of a rapid test for group A streptococci will be ready during consultation.
The result is read after 18-24 hours from the specimen taking. If the result is negative, the growth is re-examined the next day.
During an epidemic, throat culture is used. It also provides antimicrobial sensitivity testing.
The physician should see all children and those adults who have deteriorated general condition, difficulty swallowing, a primary disease that may be worsened by the throat infection, or who otherwise present with an atypical clinical picture or with signs or symptoms suggesting complications, e.g. with trismus (lockjaw) or significant difficulty swallowing.
Adult patients in good condition can usually be examined by a trained nurse. A throat swab is taken from symptomatic patients according to Centor symptom score, and further measures are agreed on locally.
Antimicrobials are indicated only for patients with a positive rapid test or culture for either
group A streptococci or
any streptococci if the symptoms are severe, particularly during an epidemic.
Follow-up throat culture after treatment is not necessary.
The initiation of medication can well be postponed until the rapid test or culture result confirms the diagnosis provided that the patient doesn't have a high fever.
The cellulitis preceding the development of the actual abscess, known as peritonsillitis, presents with similar symptoms, and the definite diagnosis can only be confirmed when pus can be retrieved from the area e.g. by aspiration.
Antimicrobial treatment is the same which is used for an abscess that is treated without surgical drainage.
Recurrent tonsillitis
Tonsillitis at least 3 times within 6 months or 4 times within a year
The most common causes of recurrence: beta-lactamase-producing normal flora in the throat, poor adherence to treatment, streptococcal carrier state, new infection from a person in near contact
In recurrent infection first-line therapy is cephalexin that erases group A streptococci even more efficiently than penicillin. Clindamycin (300 mg 3-4 times daily for 10 days) also erases group A streptococci and prevents recurrent tonsillitis caused by other bacteria as well.
A streptococcal epidemic should be suspected if several patients fall ill in the same location within a short time (15-20% of the same group of people within two weeks or several family members within one month).
Epidemics commonly occur in child day-care settings, schools, military units and care institutions.
If the epidemic is severe, consider also the possibility of a food-borne infection Food Poisoning.
Throat cultures should be taken from all symptomatic and asymptomatic persons belonging in the group; in the initial phase, cultures can at discretion also be taken from their symptomatic family members.
All persons with positive cultures are treated simultaneously and the spread of infection is prevented by avoiding their contacts with other persons for 24 hours whether they have symptoms or not. Symptomatic patients may need a longer isolation. Control samples are not needed after treatment.