Introduction
Allergic contact cheilitis due to lip cosmetics
Clinical features
Irritant contact cheilitis due to lip cosmetics
Contact urticaria due to lip plumpers
Lipsticks and other lip care products such as lipliners, lip balms/salves, lip gloss, lip plumpers and sunscreens can cause:
Cheilitis is the medical term for inflamed lips.
A basic lipstick is composed of the stick, emollient, solvent for the dyes, preservatives/antioxidants, perfumes/flavourings and colours. Further chemical agents may be added for gloss, water-resistance, sealant, cushioning, texture and richness.
Lipsticks and lip care products are the commonest cause of allergic contact cheilitis in women. And as the majority of patients presenting with cheilitis are women, this makes these products the most common overall source of allergens. Toy make-up may contain high levels of fragrances and metals, above those recommended for cosmetics, and may play a role in sensitization. Lipsticks are regarded as moderate-risk cosmetics for the development of allergic reactions.
Lipsticks and other lip care products are the major causes of allergic contact cheilitis of the vermilion margin, where the skin and red lip meet. Sometimes the reaction extends onto adjacent perioral skin, with or without the involvement of the angles of the mouth.
The reaction may present in either acute or more persistent chronic forms.
Acute allergic contact cheilitis may mimic contact urticaria, with swelling and small blisters within minutes of contact with the allergen. The reaction may spread to the face and neck.
The chronic form, however, presents with redness, scaling or dryness, and itch. This may be associated with mild swelling. Typically it begins within hours of contact and may persist for days, weeks or months, if exposure to the allergen continues.
Pigmented allergic contact cheilitis has also been reported due to lipsticks.
Patch testing is the investigation for contact allergy due to Type IV (delayed) hypersensitivity. Patch testing should include the baseline series and an extended series such as perfumes/flavourings and other components found in lip care products. It is important to also test the patient's own products as in a significant number of cases the patient only reacts to these.
Many cosmetic companies are willing to co-operate with dermatologists to find the specific allergen in their product. They will usually supply de-identified samples which can be used for patch testing and will then identify the chemical that gives a positive patch test. This means the patient knows what to avoid in future and provides the cosmetic company with feedback about a possible problem with their product. It is not uncommon for a patient to react to more than one allergen in lip care products.
Avoidance of the allergen usually results in resolution of the inflammation. Sometimes however there is more than one contributing factor to the cheilitis and it is, therefore, important to be re-assessed if the cheilitis persists despite not using the identified product.
Eosin, or a contaminant of it, was the commonest allergen identified in lipsticks up until 1960. Since then eosin has been used less often in lipstick formulations and is also more highly purified, so is rarely a problem now.
Ricinoleic acid, the main constituent of castor oil, has been identified in several large case series as the commonest current cause of allergic cheilitis due to lip cosmetics.
Some other allergens identified in lipsticks and lip care products as causing allergic cheilitis reactions:
Additional components may include:
Irritant contact cheilitis is a diagnosis of exclusion, made when investigations for an allergic cause have been negative, the patient is not atopic and lip-licking (perlèche) has not been observed. Manufacturers avoid well-known irritants, but mild irritants may still be present.
Some components of lip care products can be both irritant and allergenic. Examples of such irritants include olive oil, citral, shellac and cinnamon.
As with allergic contact cheilitis, there should be an improvement when the source of irritation is avoided. Lip licking in response to the dryness may continue an irritant dermatitis despite avoiding the original irritant.
Lip plumpers are cosmetics used to increase the apparent volume of the lips either by vasodilation or hydration. Vasodilation may be achieved by one of three mechanisms:
Lip swelling is the desired effect following use of lip plumper. However, a kiss soon after application of the product may result in an unintended transfer of the reaction.
