What is eczematous cheilitis?
Eczematous cheilitis is inflammation of the lips presenting as redness with dryness and scaling. It may also be called lip dermatitis. The lips may be divided into three zones – the outer zone comprising the skin next to the lips, the vermilion margin and the mucosal aspect. The first two areas are the most commonly affected. The major causes of eczematous cheilitis are atopic dermatitis and irritant or allergic contact reactions.
Who gets eczematous cheilitis and why?
Eczematous cheilitis can be divided into two major groups based on the cause:
- Endogenous, meaning it is due to an inherent characteristic of the person. Atopic dermatitis is the most common example of this form.
- Exogenous, meaning it is due to something from outside the body. This group can be further subdivided into:
- Irritant contact cheilitis – lip licking is the major cause of this type (perlèche). Other common causes of irritant cheilitis include cosmetics, foods and environmental factors.
- Allergic contact cheilitis – a relevant allergic reaction is identified in at least one quarter of cases of eczematous cheilitis. Common sources of allergens include lipsticks and other lipcare products, toothpastes and dental materials, foods, medications and nail varnish.
Often a combination of factors is present.
Rarely contact urticaria may present as a cheilitis when the allergen is used in small amount frequently, such as the flavouring in a toothpaste.
Sometimes no cause can be identified.
Clinical features of eczematous cheilitis
The chronic form of eczematous cheilitis presents with redness, dryness, scaling and fissuring. The angle of the mouth is often also involved (angular cheilitis).
The perioral skin and vermilion margin (where the red mucosa meets the skin) are the most commonly affected parts of the lips.
It is important to look for and note skin and mucosal lesions elsewhere as these may give a clue as to the cause.
How is the cause of eczematous cheilitis identified?
Careful history and examination may help to narrow down the list of possible causes. Examination should include not only the lips, but inside the mouth and the skin in general.
Patch testing is very useful in eczematous cheilitis as at least one quarter of cases involve an allergic reaction. Testing should include the standard series as well as extended series such as for lipsticks, toothpastes and others as suggested from the history. Testing the patient’s own products ‘as is’ is important. Photopatch testing may also be useful. The relevance of positive reactions must be considered.
Treatment of eczematous cheilitis
Treatment will depend on the cause. Where an exogenous cause has been identified, this should be avoided if possible. If this does not result in improvement, consider another factor such as a second allergen, irritant or endogenous cause.