Common Causes of Mouth Blisters
1. Canker Sores (Aphthous Ulcers)
- Appearance: Small, round, white or yellow ulcers with a red border.
- Location: Inside the mouth — cheeks, tongue, gums, or inner lips.
- Cause: Stress, minor injury (like biting your cheek), acidic foods, or hormonal shifts.
- Note: Not contagious.
2. Cold Sores (Herpes Simplex Virus)
- Appearance: Painful fluid-filled blisters that may crust over.
- Location: Usually on or around the lips, sometimes inside the mouth.
- Cause: HSV-1 virus, triggered by stress, illness, or sun exposure.
- Note: Highly contagious.
3. Friction Blisters or Burns
- Appearance: Clear or white bubbles that may be tender.
- Location: Anywhere in the mouth.
- Cause: Hot foods, sharp foods, accidental biting.
- Note: Usually heal quickly on their own.
4. Mucocele
- Appearance: A soft, bluish blister or bump.
- Location: Inside of the lower lip or under the tongue.
- Cause: Blocked salivary gland due to lip-biting or trauma.
- Note: Usually harmless but can become chronic.
5. Hand, Foot, and Mouth Disease
- Appearance: Red spots or blisters inside the mouth, often with a rash on hands and feet.
- Location: Tongue, cheeks, roof of mouth.
- Cause: Viral infection (Coxsackievirus).
- Note: Common in children but adults can catch it too.
Less Common but Concerning Causes
1. Pemphigus Vulgaris
- A rare autoimmune condition causing painful blisters in the mouth and other mucous membranes.
- Blisters may burst easily, leaving raw areas.
- Requires medical treatment and monitoring.
2. Oral Lichen Planus
- Chronic inflammatory condition that may cause white patches or painful sores.
- Not infectious, but may be linked to autoimmune activity.
3. Oral Cancer
- Persistent sores or blisters that don’t heal after 2 weeks should always be evaluated.
- Other signs: unexplained bleeding, lump in the mouth, difficulty swallowing.
