What should you know about commissural cheilitis?

The mouth corners can stay damp from saliva, lip licking, drooling during sleep, or saliva collecting in deeper folds. Repeated wetting followed by drying can weaken the skin and produce a split that stings when you eat, speak, or open your mouth widely.

The area may look red, swollen, scaly, raw, or crusted. Irritant contact, eczema, thrush, or bacteria can contribute, and more than one factor may be present. A clinician may examine the skin and mouth and may consider a swab or other test when the appearance or response to treatment is unclear.

Gently rinse the area and pat it dry rather than rubbing. Avoid licking the corners, picking crusts, and applying fragranced lip products or products that sting. A plain protective ointment can reduce contact with saliva while the skin heals; see the guidance on [Emollient Therapy](/treatments/medical-dermatology/emollient-therapy/).

If the cracks persist, recur, spread, or interfere with eating, arrange a dermatology or primary-care assessment. Treatment depends on the cause and can include an antifungal or antibacterial medicine, management of an underlying skin condition, or a short prescribed anti-inflammatory treatment. Do not use a steroid cream on the mouth corners without advice; [Topical Corticosteroids](/treatments/medical-dermatology/topical-corticosteroids/) need appropriate selection and use on delicate facial skin.

Seek prompt medical advice if redness or swelling is rapidly worsening, pus or extensive crusting develops, pain becomes marked, or the problem extends beyond the mouth corners. An assessment is also sensible when the area does not settle with gentle protection, keeps returning, or you have difficulty eating or drinking.

Get urgent help for facial swelling with trouble breathing or swallowing. Mention recent dental work, new oral or skin products, dentures, lip-licking, and any medicines or health conditions that could affect healing.

Ask what appears to be driving the inflammation, whether testing is needed, which product is safe near the mouth, and how long to use it. You can also ask how to prevent saliva from collecting at the corners and whether a dental or skin review would be useful if the cracks recur.