Patient’s allergic reaction to penicillin might well have been a simple virus

MY patient had come down with a troublesome bacterial skin infection – but it was nothing a bit of penicillin wouldn’t fix.

“Unfortunately, I’m allergic to penicillin,” he explained.

When he was a toddler he’d been prescribed the antibiotic for a virus – and developed a rash.

It had been declared an allergy to penicillin and he’d been instructed to avoid it.

Although penicillin allergy is commonly reported, it is thought that fewer than one in five of those who think they are allergic to penicillin actually are.

While some who have an allergy to drugs can experience anaphylaxis, a potentially deadly reaction, most experience a milder response. Perhaps they’ll get itchy eyes or a rash. These symptoms can be treated with antihistamines, but the drug should still be avoided.

Of course, antibiotics like penicillin can produce side-effects. Things like nausea, vomiting and diarrhoea. Sometimes these are mislabelled as an allergy.

In my patient’s case, I discovered from his records that he had had a different form of penicillin as an older child, without any problems.

I told him the rash as a toddler was probably caused by the virus infection and not penicillin at all. So I decided we’d give it another go – but he was to stop it if he developed any allergic symptoms and contact a doctor immediately if he felt his lips and tongue swelling.

Bear in mind your doctor might not have access to your full medical records.

So if you do have a drug allergy then my advice would be to keep a note of it, and exactly how it affected you. It’ll make it much easier for your doctor to assess which medicine might help.