Systemic antibiotics are being overprescribed in Australia for impetigo and the blame lies partly in the lack of clear recommendations against this in dermatology guidelines, researchers say.

A review of data from 683 GP registrar consultations for new cases of impetigo found that solely systemic antibiotics were prescribed in 306 (44.8%), both systemic and topical antibiotics in 100 (14.6%)  solely topical antibiotics in 239 (35%) and 38 (5.6%) of patients were not prescribed antibiotics.

The study investigators said the rates of prescribing of systemic antibiotics by Australian early career doctors were much higher those seen in other countries such as Holland, where only 14% of patients with impetigo were prescribed oral antibiotics, while 64% were managed with topical antibiotics and 22% were managed without antibiotics.

The difference might be because dermatology guidelines in countries such as Holland and New Zealand encourage the use of topical antibiotics first line, irrespective of impetigo severity, and also encourage non-antibiotic treatment for limited lesions.

In contrast, Australia’s Therapeutic Guidelines Dermatology currently recommend topical antibiotics for ‘localised skin sores’ and systemic antibiotics only for ‘multiple skin sores or recurrent infection’ but do not define ‘localised’ or ‘multiple’, they noted.

“This lack of definition may explain high proportions of systemic antibiotic prescribing in our Australian early-career GPs,” they wrote in BMJ Open.

The lack of clarity in dermatology guidelines for impetigo “allows room for significant subjectivity and variation in clinical decision-making, potentially compromising antibiotic stewardship.”

Guidelines should also include explicit wording to discourage prescribing of both topical and systemic antibiotics for new impetigo case, the study authors advised.

Inappropriate use of broad spectrum systemic antibiotics is another area where guidelines could be better worded. In the Australian study, cephalexin was the most commonly prescribed antibiotic (54%) despite di/flucloxacillin being recommended as first line systemic antibiotic for treatment of impetigo.

“Australian guidelines for impetigo comment that cephalexin may be used instead of flucloxacillin for children due to greater tolerability and better palatability of the liquid formulation,” the authors noted.

“Though medication compliance is important, this ‘escape’ clause in Australia may foster a culture that allows unnecessary broad-spectrum antibiotic prescription simply because it is ‘easier’ than using appropriate narrow-spectrum treatment.”

They observed that most European guidelines and the NZ guidelines do not recommend cephalexin, and flucloxacillin is usually prescribed.

“More clarity of guidelines, including criteria for severity of disease, could steer towards more appropriate use,” the study authors concluded

Australian Therapeutic Guidelines recommendations for impetigo

• For localised skin sores, recommendation is: mupirocin 2% ointment.
• For multiple impetigo lesions or recurrent infection, recommendation is: di/flucloxacillin (cephalexin may be used for patients with non-immediate hypersensitivity to penicillins or in children due to greater tolerability and better palatability of liquid formula).
• For patients with anaphylaxis to penicillins, the recommendation is: trimethoprim+sulfamethoxazole.