AKT · ENT/Throat & airway

Pharyngitis / tonsillitis

Inflammation of the pharynx/tonsils (viral, or Group A Strep)

Overview

Inflammation of the pharynx and tonsils, mostly viral; the key bacterial cause is Group A Streptococcus (Strep pyogenes). The clinical task is to use the Centor/FeverPAIN scores to target antibiotics, and to spot quinsy and the glandular-fever mimic.

Recognise

Sore throat, odynophagia, fever; red/enlarged tonsils ± white exudate; tender anterior cervical lymph nodes
Viral features (cough, coryza, conjunctivitis) point AWAY from bacterial cause
Centor (exudate, tender anterior nodes, fever history, NO cough) and FeverPAIN scores estimate the streptococcal probability

Red flags

Trismus + "hot-potato" voice + uvular deviation → quinsy; drooling/stridor/unable to swallow → epiglittitis/airway; unilateral persistent tonsil enlargement/ulcer → malignancy

Differentials & how to tell them apart

Infectious mononucleosis (EBV)adolescent, gross tonsillar enlargement, marked malaise, splenomegaly, lymphocytosis — AVOID amoxicillin (causes a rash)

Quinsy (peritonsillar abscess)unilateral, trismus, uvular deviation, "hot-potato" voice — needs drainage

Viral pharyngitiscough/coryza, no exudate, low Centor — no antibiotic

Diphtheriagrey adherent pseudomembrane (rare, unimmunised)

Acute tonsillitis — erythema and exudate
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Investigations

Clinical + Centor/FeverPAIN scoring. Throat swab/rapid antigen not routinely needed. If glandular fever suspected (adolescent, marked malaise, lymphadenopathy) → Monospot/EBV serology + FBC.

Management

Analgesia + safety-net; phenoxymethylpenicillin if Centor ≥3 / FeverPAIN ≥4

1Analgesia and safety-netting for most (viral, self-limiting). Use Centor/FeverPAIN: low scores → no antibiotic; high scores (Centor ≥3 or FeverPAIN ≥4) → phenoxymethylpenicillin (or a back-up prescription for intermediate scores).Gate: Do NOT give amoxicillin/ampicillin if glandular fever (EBV) is possible — it causes a florid maculopapular rash; use phenoxymethylpenicillin, and clarithromycin if penicillin-allergic
2Penicillin allergy → clarithromycin/erythromycin. Quinsy → drainage + antibiotics; recurrent severe tonsillitis meeting criteria → consider tonsillectomy.

Analgesia (paracetamol/ibuprofen) — the mainstay; most are self-limiting

Phenoxymethylpenicillin (penicillin V), 5–10 days — first-line antibiotic when indicated by score

Clarithromycin/erythromycin — penicillin allergy

(Avoid amoxicillin/ampicillin) — causes a rash if it is actually glandular fever

Key points

Score it (Centor/FeverPAIN) rather than treating every sore throat. Penicillin V, not amoxicillin (EBV rash). Unilateral trismus = quinsy; persistent unilateral tonsil mass = cancer.

Monitor & prognosis

Resolution; complications (quinsy, abscess); recurrence frequency.

Self-limiting; antibiotics modestly shorten streptococcal disease.

Source: NICE NG84 (sore throat - acute); NICE CKS