2. What kind of skin problems are known to be caused by fragrance ingredients?
- 2.1 What is contact allergy?
- 2.2 What ‘other’ non-allergic reactions to fragrance ingredients are observed?
- 2.3 How can contact allergies be diagnosed?
- 2.4 How common is perfume allergy and can it be avoided?
2.1 What is contact allergy?
Skin rashes can be caused by fragrance ingredients, but are usually not allergic reactions.
Source: James Heilman
Contact allergy to fragrance ingredients occurs when an individual has been exposed on the skin to a sufficient dose of a fragrance allergen, for example through its presence in the cosmetic product. It is a life-long, specifically altered reactivity of the immune system involving recognition of the fragrance allergen(s) by immune cells. Once a contact allergy has been developed, cells capable of recognizing and reacting towards the allergen will always be present in the immune system. As a consequence, symptoms - allergic contact dermatitis - may occur upon re-exposure to the fragrance allergen(s) in question.
Allergic contact dermatitis is an inflammatory skin disease characterised by erythema (‘redness’), swelling and vesicles in the acute phase. If exposure continues, it may develop into a chronic condition with scaling and painful fissures of the skin. Allergic contact dermatitis to fragrance ingredients is most often caused by fragranced cosmetic products and usually involves the face and/or hands. It may affect fitness for work and the quality of life of the individual. In the process of developing allergic contact dermatitis, a distinction between the induction (‘sensitisation’) and the elicitation ‘reaction upon re-exposure to the allergen’ phase is made. More...
2.2 What ‘other’ non-allergic reactions to fragrance ingredients are observed?
Apart from allergic contact dermatitis, fragrances in perfumes and fragranced cosmetic products may also provoke irritant contact dermatitis, immediate contact reactions (contact urticaria), pigmented contact dermatitis or photosensitivity. Irritant effects of some individual fragrance ingredients are known if humans are exposed to higher concentrations. Irritant contact dermatitis from perfumes is believed to be common, but there are no existing investigations to substantiate this. Some people complain about intolerance or rashes to perfumes/perfumed products but are shown to not be allergic by testing. This may be due to irritant effects or inadequate diagnostic procedures. Fragrances may cause a dose-related contact urticaria of the non-immunological type (‘irritant contact urticaria’).
Pigmented cosmetic dermatitis refers to increased pigmentation, usually on the face/neck, often following sub-clinical contact dermatitis. Moreover, it is also known that some substances provoke allergic reactions only in the presence of UV-light (‘photo-contact allergy’). Nowadays, several substances of this type have either been banned or maximum use limits have been introduced to avoid photo-allergies in consumers. Hence, photo-allergic contact dermatitis is a relatively uncommon disease.
Fragrances are volatile and therefore, in addition to skin exposure, eyes, nose and the respiratory tract are exposed to the fragrance ingredients. It has been estimated that about 2–4% of the adult population is affected by respiratory or eye symptoms in this way. In addition to potential irritant reactions of the airways, it is known that exposure to fragrances may exacerbate pre-existing asthma. More...
2.3 How can contact allergies be diagnosed?
Contact allergy in humans to a specific perfume allergen is generally diagnosed by prognostic patch testing. This involves the application of small doses of the set of suspected allergens or the culprit product on a cotton patch either on the back or the upper arm of the patient for a period of 24 to 48 hours. In days after removal of the patch, exposed skin sites are visually examined by an expert, generally a dermatologist, for the occurrence of allergic reactions following topical exposure to the potential contact allergen. The whole process of identifying contact allergens is standardised. There are international guidelines for the application, reading and interpretation of the patch test. More...
2.4 How common is perfume allergy and can it be avoided?
Contact allergy to fragrance ingredients is relatively common disease. In Europe, it affects about 1 to 3% of the general population- and about 16% of eczema patients. Allergic contact dermatitis can be severe and widespread, with a significant impairment of quality of life and potential consequences for fitness for work. Thus, prevention of contact sensitisation to fragrances, both in terms of primary prevention (’limiting or eliminating exposure to allergens in the population’) and secondary prevention (‘avoiding re-exposure to specific sensitiser in clinically diagnosed individuals’), is an important objective of public health risk management measures. Means of limiting or eliminating exposure to limiting or eliminating exposure to fragrance allergens (‘primary prevention’) include
- Prohibition by regulatory measures or other means;
- Restriction of the maximum permissible concentration of an allergen, or critical component of natural mixtures according to different uses and product types;
- Substitution of the allergen with a suitable less or non-allergenic compounds;
- (Re-)formulating the fragrance or fragranced product with the aim of limiting or eliminating those substances for which a sensitising potential has been shown;
- Deliberate avoidance of the use of fragrances where they are not essential to the function or purpose of the finished product;
- Information, e.g. labelling so that the consumer may make an informed choice to avoid exposure to a particular ingredient.
In clinical dermatology, avoidance of re-exposure to an allergen is central to the care of sensitized patients. In this context, the valid diagnosis of sensitisation by patch testing with standardised material is a prerequisite of successful allergen avoidance. In addition to the correct clinical evaluation and diagnosis of contact allergy to a specific fragrance allergen, ingredient labelling of fragrance allergens is an important tool for clinicians to optimize the investigation of their patients with suspected fragrance allergy, as well as for fragrance allergic patients for avoiding products containing substances they have been shown to be allergic to. Both these aims are objectives of secondary prevention and seem to have been well accepted. More...