Sore Throat (acute) Lawrence Pike

Definitions Pharyngitis Tonsillitis Laryngitis predominantly inflammation of the oropharynx, but not the tonsils. Tonsillitis when the tonsils are particularly affected. Laryngitis few signs of infection visible but the patient complains of soreness lower down the throat often with a hoarse voice.

Causes Viral (70-80%) Group A beta-haemolytic streptococcus (20-30%)

Incidence Sore throat is estimated to account for 10% of all general practice consultations Asymptomatic carriage of streptococcus is common with rates of 6 - 40% Carriers have low infectivity and are not at risk of developing complications such as rheumatic fever

Symptoms Sore throat Pain on swallowing Fever Headache Malaise Hoarseness if laryngeal involvement

Signs Redness of the pharynx and tonsils Presence of exudate Enlarged tonsils Swollen tender neck glands. Note that a streptococcal sore throat is impossible to diagnose on clinical grounds alone.

Scarlet Fever A red punctate skin eruption with sandpaper-like texture Usually begins on chest and spreads to abdomen and extremities Prominent in skin creases Flushed face with circumoral pallor Strawberry tongue These indicate a streptococcal infection

Investigations? Throat swabs cannot differentiate between "infection" and "carriage", are poorly sensitive, and are therefore of limited value. Results take up to 24 - 48 hours to be reported, and the test is relatively expensive. Rapid antigen tests to detect streptococcal antigen on a throat swab are not easily available. Anti-streptolysin O (ASO) titres can help to identify whether a patient has recently been infected with streptococcus, and may be useful for patients who remain unwell or develop complications.

Differential Diagnosis Infectious mononucleosis (glandular fever) Epiglottitis (requires urgent admission) Gonococcal pharyngitis (rare) Diphtheria (very rare in U.K) Neutropaenia (e.g. ensure patient not on carbimazole)

Complications Otitis media Sinusitis Peritonsillar abscess (quinsy) Suppurative cervical adenopathy Rheumatic fever Post streptococcal glomerulonephritis

Management Sore throat (pharyngitis, tonsillitis, laryngitis) is usually a self-limiting illness, whether due to viral or bacterial infection. Explanation, reassurance and advice on symptomatic treatment is frequently all that is necessary when a patient consults with a sore throat, as only a third clearly want or expect an antibiotic.

Management Prescription of an antibiotic increases patient reattendance rates for further episodes of sore throat. The patient is also exposed to the risk of side effects Increased risk of bacterial resistance in the community. Antibiotic therapy of sore throat reduces duration of symptoms by about 8 hours, although it is not known if symptom severity is also affected. The absolute benefit is small, with 90% of both treated and untreated patients symptom free within one week.

Management Antibiotic therapy has a small protective effect on the risk of developing sinusitis, otitis media and possibly peritonsillar abscess (quinsy). 30 children and 145 adults need treatment to prevent one case of acute otitis media. ]

Management Benefit in reducing the incidence of rheumatic fever or post streptococcal glomerulonephritis is likely to be low. The incidence of rheumatic fever and post streptococcal glomerulonephritis has fallen in industrialised countries and does not appear to be related to antibiotic use. Although early studies showed that antibiotic treatment decreased the risk of these complications more recent studies have not shown benefit.

Management Suggested indications for antibiotics are: severely inflamed throat with marked systemic upset confirmed streptococcal infection scarlet fever patients with impaired immunity (splenectomy) past history of rheumatic fever or post-streptococcal glomerulonephritis. Antibiotic treatment is also usually advised during outbreaks of streptococcal infection in communities such as schools, hostels or prison (public health).

Management If an antibiotic is necessary Penicillin is the treatment of choice, with erythromycin in patients with penicillin allergy. 10 days treatment is recommended in order to eradicate possible streptococcus infection. [DTB 1995] Tonsillectomy is occasionally recommended for recurrent attacks of tonsillitis. Consider only if seven documented throat infections in the preceding year, or three in each of three successive years.