Rash from terbinafine: what to know

Terbinafine can be taken by mouth or applied to the skin, and the location of a rash matters. A local reaction at an application site may differ from a widespread eruption after oral treatment. The original fungal infection can also remain scaly or inflamed while healing, so appearance alone is not enough to identify the cause.

Drug Rash may be mild, but pain, blistering, peeling or sores on the mouth, eyes or genitals need urgent assessment. Tell the clinician whether you use tablets, cream or both, and mention all other medicines.

Pause and seek advice from the prescriber or pharmacist before applying another dose or taking another tablet. Keep the medicine packaging, note the start date and photograph the rash in good light. Avoid scratching, fragranced products and unadvised steroid combinations.

If oral antifungal treatment is needed for the original infection, a clinician can decide whether to continue, change or stop it and whether testing or a different approach is appropriate. Read more about Terbinafine and Oral Antifungal Treatment during that discussion.

Seek emergency help for breathing difficulty, facial or tongue swelling, faintness, widespread blistering, peeling skin, severe skin pain, fever with a rapidly spreading rash, or sores involving the eyes or mouth. Do not wait for the rash to become extensive.

Is this more consistent with a medicine reaction or the infection being treated? Should I stop the cream or tablets now? What alternative treatment is safe, and should terbinafine be listed as a suspected allergy?