Blister sore in mouth

A mouth blister or sore may follow trauma, an ulcer, infection, or irritation; care depends on its appearance, location, and duration.

A sore can occur on the inner cheek, lip, tongue, palate, or gum. A single shallow ulcer may be painful with eating, while a fluid-filled lesion, a rubbing sharp tooth, or a cluster of sores has a different clinical pattern.

Avoid picking the area and choose cool, soft foods while avoiding spicy, acidic, or rough foods that sting. Use a soft toothbrush and ask a pharmacist or dentist about a suitable topical product if pain makes eating difficult.

Arrange an examination if the sore persists, repeatedly returns, grows, bleeds, feels hard, or lies beside a sharp tooth or denture. Seek prompt care for fever, spreading swelling, dehydration, or difficulty swallowing or breathing.

Ask what the lesion most resembles, whether a tooth or appliance is rubbing it, and whether a swab, biopsy, or other test is needed. Ask how to protect the site and what change should prompt review.