What causes angular cheilitis?

Saliva exposure is a frequent starting point. Yeast or bacteria can take advantage of the damaged surface, but infection is not the only possibility. Several triggers can operate together, so the same-looking crack may require different treatment in different people.

Lip licking, drooling, dry mouth, and repeated wiping create cycles of wetting and drying. Dentures that do not fit well, loss of dental support, or a deep skin fold at the mouth angle can allow saliva to pool. Cold or dry conditions may add cracking.

Eczema and reactions to toothpaste, cosmetics, or dental materials can inflame the area. Iron or vitamin deficiency, diabetes, immune suppression, and medicines that affect the mouth or skin are possible underlying contributors, especially when episodes recur. These factors cannot be identified from appearance alone.

Keep the corners clean and dry without scrubbing, then apply a simple fragrance-free barrier to limit contact with saliva. Address lip licking and note whether sleep drooling, a dental appliance, or a recently introduced oral-care product lines up with the flare.

A health professional can decide whether an antifungal, antibacterial, anti-inflammatory, or protective treatment is appropriate. Persistent cases may prompt an oral examination, denture review, swab, or blood tests guided by symptoms and medical history. Avoid sharing medicated creams or combining treatments without advice.

Arrange care when cracking repeatedly returns, affects both corners for a prolonged period, extends onto surrounding skin, or fails to improve despite careful moisture control. Also report tongue soreness, other mouth changes, unusual tiredness, increased thirst, or problems with a denture.

Get urgent help if swelling progresses quickly, redness spreads across the face, pus or fever develops, or swallowing or breathing becomes difficult. Those findings need prompt evaluation rather than another trial of lip balm.

Ask which cause is most consistent with the pattern, whether infection is present, and whether dental fit or an underlying condition should be checked. Bring a list of creams, lip products, toothpaste, medicines, supplements, and the timing of recent changes.