Sunburn Lip Blister: What to Know

Sunburn is inflammation caused by ultraviolet exposure. Lip skin is thin and exposed, so it can become sore, swollen, tight, cracked, or blistered. A blister is a fluid-filled response from damaged upper skin; it does not by itself identify the cause. A cold sore, contact reaction, or infection can also affect the lip, especially if lesions recur in the same spot or start with tingling. See [Sunburn](/conditions/sunburn/) for the broader condition and [Skin Blisters](/symptoms/skin-blisters/) for this symptom.

Move out of direct sun and use a broad-brimmed hat or other shade. Cool the area gently with a clean, cool damp cloth; avoid ice directly on the lip. Do not pop, peel, or pick the blister, because the covering helps protect the tender surface. Apply a bland, fragrance-free lip emollient to reduce dryness, choosing a product that does not sting. Sip fluids and choose cool, soft foods if the mouth feels tender. Avoid acidic, spicy, salty, or very hot foods until comfort improves. Do not apply numbing products, exfoliants, or steroid cream to the lip unless a clinician has advised it. Learn more about [Emollient Therapy](/treatments/medical-dermatology/emollient-therapy/).

Arrange medical advice if the blister is extensive, increasingly painful, repeatedly returns, or does not begin settling. Seek prompt care for spreading redness, warmth, pus, fever, marked swelling, trouble drinking, trouble swallowing, or breathing difficulty. A clinician should assess a blister near the eye, a weakened immune system, or a suspected cold sore, since treatment differs. Do not burst a large blister yourself.

Could this be sunburn, a cold sore, or another lip reaction? Should I use a particular emollient, pain reliever, or prescription treatment? What changes would mean the blister needs examination? How can I protect my lips during future sun exposure?