Should Antibiotics Be Used to Treat Minor Skin Abscesses?

I remember the days when the aura of the miraculous still surrounded antibiotics. The problem of bacterial resistance on any scale was only just beginning and doctors handed them out more or less on demand. I remember a patient who said she was taking them for her headaches and when I refused to prescribe them for her she threatened the receptionist with violence. The latter threatened to resign unless I prescribed them, so I relented. Such are the vagaries of scientific prescribing.

The pendulum has swung the other way, as pendulums usually do. There is now almost a puritanical attitude toward the prescription of antibiotics and a presumption against their use in minor infections.

A recent paper in the New England Journal of Medicine studied the question of whether antibiotics in addition to surgical drainage was advantageous in the cure of minor skin abscesses. The antibiotic chosen for evaluation was an old one, the combination of trimethoprim with sulfamethoxazole, to which the causative organism of most such abscesses, Staphylococcus aureus, is still sensitive, though it had become largely insensitive to forms of penicillin.

1247 patients with skin abscesses requiring surgical draining were allocated randomly to surgery plus antibiotics for 7 days or surgery plus placebo for 7 days. Their rates of cure and complications were subsequently compared.

In fact, the results in only 1013 of the original patients could be compared, the rest having been excluded for various reasons, among them that 105 of them had taken less than 75 per cent of the pills prescribed, 44 in the placebo group and 61 in the antibiotic group. Only 64.7 per cent of the patients took the pills exactly as prescribed: an important point not emphasised by the authors for if patients in clinical trials with unusually close attention and follow-up do not take pills as prescribed, how many of them would do so in more ordinary circumstances? Incompletely-taken courses of antibiotics favor the emergence of bacterial resistance.