Strep A & Strep Throat in Ireland — When to Test, When to Treat

What is Strep A?

Group A streptococcus (GAS) is a bacterium that causes a range of infections, from common (strep throat, scarlet fever, impetigo) to rare and serious (invasive Strep A — sepsis, necrotising fasciitis). Most exposure to Strep A causes either no illness or mild self-limiting infection. The vast majority of sore throats — even during Strep A outbreaks — are viral and do not need antibiotics.

Strep throat — clinical features

Strep throat tends to present with:

• Sudden-onset severe sore throat
• Fever
• Tender, enlarged neck glands
• Tonsillar exudates (white spots)
• Absence of cough
• Sometimes headache, abdominal pain, scarlet-fever rash

However, viral infections (adenovirus, EBV "glandular fever", and others) can mimic these features. The distinction is not always obvious clinically.

Clinical scoring — Centor and FeverPAIN

Per NICE CKS and ICGP guidance:

Centor criteria (1 point each)

• Tonsillar exudate
• Tender anterior cervical lymphadenopathy
• Fever (history of)
• Absence of cough

Scores: 0–2 — likely viral, no antibiotics. 3–4 — higher probability of strep; consider testing or empirical treatment.

FeverPAIN (1 point each)

• Fever in past 24 hours
• Purulent tonsils
• Attended within 3 days of onset (rapid)
• Inflamed tonsils (severe)
• No cough or coryza

Scores: 0–1 — likely viral. 2–3 — rapid testing or delayed prescription. 4–5 — consider immediate antibiotic if symptoms severe.

Testing

Rapid antigen tests for Strep A are available; throat swab culture remains the gold standard but takes 24–48 hours. Routine testing for everyone with a sore throat is not necessary — clinical scoring guides who benefits from testing or treatment.

Treatment

When antibiotics are indicated per NICE:

• First-line: phenoxymethylpenicillin (penicillin V) for 10 days
• Penicillin allergy: clarithromycin or erythromycin
• Symptomatic relief: paracetamol or ibuprofen; lozenges; warm fluids
• Even with antibiotics, sore throat typically lasts 5–7 days — antibiotics shorten illness by about a day and reduce risk of complications

Scarlet fever

Strep A infection with characteristic features: sandpaper-like rash, "strawberry tongue", flushed cheeks, sore throat, fever. Mandatory notification to HPSC in Ireland. Antibiotic treatment indicated. Notify your child's school. Per HPSC, scarlet fever activity in Ireland follows seasonal patterns and occasionally outbreaks.

Red flags — same-day in-person assessment needed

• Difficulty swallowing saliva or drooling
• Difficulty breathing or noisy breathing (stridor)
• Severe pain, severe trismus (cannot open mouth)
• Neck stiffness
• Hot potato voice, neck swelling — possible quinsy (peritonsillar abscess)
• Non-blanching rash (consider meningococcal disease)
• Significantly unwell child, very high fever, lethargy
• Signs of sepsis (per HSE Sepsis Six)

Online Doctor consultation

An Online Doctor can assess a sore throat using clinical scoring, advise on whether testing or antibiotics are appropriate, prescribe where indicated, and arrange in-person review for red-flag features. For children or anyone significantly unwell, in-person assessment is usually preferred.