MISTAKE EASILY MADE

A SENSITIVITY to penicillin is different from an allergy.

While sensitivity is usually characterised by diarrhoea, thrush or headache, an allergy involves the immune system over-reacting.

This causes classic symptoms ‘including an itchy rash, swelling of the lips and tongue and difficulty breathing’, explains antimicrobial pharmacist Neil Powell. An allergic reaction occurs within an hour — and often much sooner.

An upset stomach with nausea or diarrhoea after a day or two of taking antibiotics is unlikely to be an allergic reaction, but may result from the drug disrupting the gut bacteria.