What causes angular cheilitis?

Saliva can collect in the folds, soften the skin, and allow yeast or bacteria to grow. Dry or sensitive skin, lip licking, drooling, and poorly fitting dentures can contribute. Less commonly, persistent disease accompanies nutritional deficiency, diabetes, or reduced immune function.

The mouth corners stretch whenever you eat, speak, or yawn. Once their thin skin becomes soggy or dry and cracked, repeated movement reopens the area. This creates soreness, redness, crusting, or a split on one or both sides.

The appearance alone does not reliably identify the cause. A clinician may consider the pattern, denture fit, oral health, skin conditions, medicines, and signs of fungal or bacterial infection. Recurrent episodes may justify checking for an underlying contributor.

Keep the corners gently clean and dry, avoid licking or picking them, and apply a bland protective lip product to reduce saliva contact. Replace irritating cosmetics or strongly flavoured oral products if they seem to trigger soreness.

Treatment should match the suspected cause. A clinician may prescribe an antifungal or antibacterial medicine when infection is present. Anti-inflammatory creams are not suitable for every cracked mouth corner and can worsen an untreated fungal infection, so use them only as directed. A dentist can assess dentures that rub or fail to support the mouth corners.

Book an assessment if the cracks persist, repeatedly return, spread beyond the mouth corners, or make eating difficult. Seek prompt care for increasing swelling, pus, rapidly spreading redness, fever, or feeling generally unwell. People with diabetes or a weakened immune system should have persistent mouth-corner inflammation assessed early.

Ask whether the pattern suggests irritation, yeast, bacteria, or another lip condition; whether a swab or blood test would change management; and whether dentures, medicines, dry mouth, or nutritional health could be contributing. Confirm exactly where and how long to apply any prescribed product.