SIGN guideline no34 (1999) recommends
- Be aware of psychosocial influences in patients presenting with sore throat.
- Clinical examination does not reliably differentiate between viral and bacterial
- Throat swabs & rapid antigen testing should not routinely be done
- No recommendation about routine antibiotics! Should not be used for symptomatic relief or to prevent long term complications; but should not be withheld if "concerned about clinical condition".
- Antibiotics may prevent cross-infection with Gp A Strep in closed institutions
- Infectious mononucleosis may present with exudate and lymphadenopathy so ampicillin/amox based antibiotics should not be used as first line
- In recurrent sore throat with Gp A Strep a 10 day course of Penicillin may reduce the frequency of attacks
- Tonsillectomy should be considered if all the following criteria are present:
- sore throats are due to tonsillitis
- five or more episodes of sore throat per year
- symptoms for at least a year
- the episodes of sore throat are disabling and prevent normal functioning.
- A six month period of watchful waiting is recommended prior to tonsillectomy to
establish firmly the pattern of symptoms and allow the patient to consider fully the
implications of operation.
- Once a decision is made for tonsillectomy, this should be performed as soon as possible,
to maximise the period of benefit before natural resolution of symptoms might occur
(without tonsillectomy).
These conclusions are mostly based on a Cochrane review, however the review included few studies in children and included studies where Gp A strep had not been distinguished from other causes. So the suggestion that there is only a 1 day benefit in symptoms is probably an underestimate in true strep infection. Carapetis argues that doing a swab and starting empirical treatment is reasonable and that antibiotics can be stopped in light of results. Ultimately, decision to treat is often influenced by psychosocial factors.
Review suggests that 6 days amoxicillin, 4 to 5 days cephalosporins and 5 days azithromycin are as or more effective than penicillin and probably better complied with. Brook, Pediatric Drugs, 2002;11: 747-754. Azithromycin 60 mg/kg per course was superior to the 10-day courses of other antibiotics on metanalysis, with bacterial failure occurring 5 times more often in patients receiving the 10-day courses of antibiotics (30 mg/kg course was inferior). Clin Infect Dis. 2005 Jun 15;40(12):1748-55. Pen V given 2 or 3 times a day (for the same daily dose) does not affect rate of clinical cure Scandinavian Journal of Infectious Diseases. 23(6):755-61, 1991.
Factors distinguishing Strep from non strep:
- presence of sore throat
- tonsillar swelling
- anterior cervical adenopathy
- scarlatiniform rash
Not: fever, tonsillar exudate, or palatal petechiae! But none of the above reach PPV more than 50%. Source?
McIsaac score has been prospectively validated in a mixed population of children and adults:
- history of or measured temperature >38°C,
- absence of cough,
- tender anterior cervical adenopathy,
- tonsillar swelling or exudate,
- and age <15 years.
Points are summed to a maximum score of 4. Important to estimate pretest probablility when looking at studies of sens/spec or cost effectiveness.
More than half of kids with suspected viral URTI are still unwell 4 days after initial consultation and a quarter are still unwell after a week (on parentally reported symptom scale).
