Role of microbiological studies in management of peritonsillar abscess

Peritonsillar abscess (quinsy) is one of the most common ENT emergencies. A 2002 UK audit of quinsy management revealed that an average ENT department treated 29 cases annually; the most common treatment was needle aspiration with intravenous antibiotics, and culture of the aspirate was often performed routinely. The aims of our study were to evaluate the value of routine culture of quinsy aspirates, and to establish whether the information thus gained was clinically useful.

We examined the notes of patients admitted with quinsy to two hospitals in south-west England, from January 1998 to January 2004 in one hospital and from January 1995 to January 2005 in the other. A total of 577 cases was found. Aspirated pus had been sent for culture in 119 (21 per cent). These cases were examined in more detail.

Of the 119 patients, 78.2 per cent (93/119) were treated with either a cephalosporin or penicillin, plus metronidazole. Streptococcal species were cultured in 43.7 per cent (52/119) and anaerobes in 23.5 per cent (28/119; of these cultures, 5.9 per cent (7/119) were pure anaerobes only). All the anaerobes were sensitive to metronidazole. One of the 119 cultures, growing aerobic bacteria, was resistant to penicillin; however, this patient improved clinically on a combination of penicillin and metronidazole. No patients had their treatment changed because of culture results.

There appears to be no need to routinely culture quinsy aspirates, based upon our findings (of 16 hospital years) and previous studies (which found no recorded episodes of treatment change as a result of culture sensitivities). The combination of penicillin or a cephalosporin, plus metronidazole appeared to be theoretically effective in 99.2 per cent (118/119) of our specimens; this finding is supported by other studies. However, the rare but potentially life-threatening complications of quinsy must be recognised.