Abstract
Contact dermatitis is a common cause of eczematous cheilitis. In a Singapore series, allergic contact dermatitis is commoner than irritant contact dermatitis. More females are affected than males. Eczematous cheilitis usually presents in the 3rd and 4th decades of life. Eczematous cheilitis tends to occur among office workers and professionals (50.5%). This is probably due to the more frequent use of cosmetics and lip preparations among office workers compared to ‘blue collar’ workers. Irritant contact cheilitis is often seen in individuals with an underlying endogenous tendency to eczema, e.g. atopic dermatitis. Contact irritants include lip cosmetics, toothpastes and dentrifices. In the early 1990s, tartar control (pyrophosphates) toothpastes were reported to cause outbreaks of irritant contact dermatitis on the lips and peri-oral skin. Other irritants include traditional Chinese medicines. Allergic contact cheilitis occurs from lip cosmetics, toothpastes and medicaments. Allergic contact cheilitis accounted for 35% of eczematous cheilitis presenting at the Singapore clinic. The commonest cause of allergic contact cheilitis was lip cosmetics. They include lipsticks, lip balms and other cosmetic preparations. In Singapore, ricinoleic acid present in lipsticks accounted for about 10% of all cases of allergic contact dermatitis. Other allergens include other lipstick ingredients, sunscreen agents, toothpaste ingredients, colophony in dental floss and toothpicks, nail varnish, cosmetics and nickel in the mouthpiece of a flute. Recently sunscreens have become a common sensitizer in lip cosmetics. Other allergens include fragrance, balsam of Peru, lanolin and flavourings (strawberry and vanilla). Toothpastes are the next most common cause of allergic contact cheilitis. Dentrifices and dental prostheses have been reported to cause allergic contact dermatitis. Diagnostic clues have to be obtained from a careful history which includes a review of oral rinses, toothpastes, cleansers, mouthwashes, dentrifices, denture materials, chewing gum and lipsticks used by the patient. Patch testing with these products is essential for investigating the possible cause of allergic contact cheilitis. However, there is a group of patients with troublesome cheilitis, who are often severely affected, but in whom the cause of the cheilitis remains obscure. This group may represent patients with endogenous cheilitis or factitious cheilitis.