Cracked Corners of the Mouth

Causes include infection, mechanical irritation, allergy, nutrition and systemic disease. Candida albicans and Staphylococcus aureus are named common pathogens; dry mouth, ill-fitting dentures and immune compromise can increase risk.

Reduce repeated licking and other behaviours that keep saliva on the corners. Dry heat, cold, drooling and over-licking can macerate or irritate the area.

Assessment starts with the appearance and a detailed history, including dentures and dental procedures. A patch test can help distinguish irritant from allergic contact dermatitis, while laboratory confirmation may help identify infection.

Treatment depends on whether infection, allergy, irritation, denture mechanics or a nutritional or systemic factor is involved. Removing the trigger and treating the identified cause are the central steps.

Clean dentures thoroughly, address denture reservoirs and rinse after inhaled corticosteroids. Avoiding allergens is important in allergic cases, and reducing saliva exposure helps protect the corners.

Severe angular cheilitis can interfere with eating and contribute to malnutrition. Associated clues may include dry eyes or mouth, diarrhoea, blood in the stool or abdominal pain when a systemic condition is involved.

A persistent one-sided lesion, recurrent infection or systemic symptoms needs further investigation. These red flags are especially important when the corner does not heal or repeatedly breaks down.