Examples of potential allergens include substances that may be present in some types of lipstick, toothpaste, acne products, cosmetics, chewing gum, mouthwash, foods, dental appliances, and materials from dentures or mercury containing amalgam fillings. It is usually impossible to tell the difference between irritant contact dermatitis and allergic contact dermatitis without a patch test. Loss of lower facial height
Severe tooth wear or ill fitting dentures may cause wrinkling at the corners of the lip that creates a favorable environment for the condition. This can be corrected with onlays or crowns on the worn teeth to restore height or new dentures with "taller" teeth. The loss of vertical dimension has been associated with angular cheilitis in older individuals with an increase in facial laxity. Diagnosis
Angular cheilitis is normally a diagnosis made clinically. If the sore is unilateral, rather than bilateral, this suggests a local factor (e.g., trauma) or a split syphilitic papule. Angular cheilitis caused by mandibular overclosure, drooling, and other irritants is usually bilateral.The lesions are normally swabbed to detect if Candida or pathogenic bacterial species may be present. Persons with angular cheilitis who wear dentures often also will have their denture swabbed in addition. A complete blood count (full blood count) may be indicated, including assessment of the levels of iron, ferritin, vitamin B12 (and possibly other B vitamins), and folate. Classification
Angular cheilitis could be considered to be a type of cheilitis or stomatitis.
Where Candida species are involved, angular cheilitis is classed as a type of oral candidiasis, specifically a primary (group I) Candida-associated lesion. This form angular cheilitis which is caused by Candida is sometimes termed "Candida-associated angular cheilitis", or less commonly, "monilial perlèche". Angular cheilitis can also be classified as acute (sudden, short-lived appearance of the condition) or chronic (lasts a long time or keeps returning), or refractory (the condition persists despite attempts to treat it). Management
There are four aspects to the treatment of angular cheilitis. Firstly, potential reservoirs of infection inside the mouth are identified and treated. Oral candidiasis, especially denture-related stomatitis is often found to be present where there is angular cheilitis, and if it is not treated, the sores at the corners of the mouth may often recur. This involves having dentures properly fitted and disinfected. Commercial preparations are marketed for this purpose, although dentures may be left in dilute (1:10 concentration) household bleach overnight, but only if they are entirely plastic and do not contain any metal parts, and with rinsing under clean water before use. Improved denture hygiene is often required thereafter, including not wearing the denture during sleep and cleaning it daily. For more information, see Denture-related stomatitis. Secondly, there may be a need to increase the vertical dimension of the lower face to prevent overclosure of the mouth and formation of deep skin folds. This may require the construction of a new denture with an adjusted bite.