Patients may be unaware of the potential for contact dermatitis arising from use of "natural" products on the skin, say Dr K. Thomson and Dr S. Wilkinson (department of dermatology, Leeds General infirmary). They describe in the British Journal of Dermatology (2000;142:84) how they investigated the incidence of allergy to fragrances and plant extracts. Reactions to plant extracts were thought to arise from direct contact with plants, or use of cosmetics or aromatherapy products containing plant extracts.
The authors found that, of 29 patients who presented for patch testing, 79 per cent showed a reaction to a standard fragrance mix and 34 per cent reacted to Balsam of Peru. Of the total number of patients, 59 per cent developed dermatitis to at least one of the plant extracts used by the authors. The extracts that most frequently caused a reaction included tea tree oil, lichen acid mix, dandelion, propolis and feverfew. Fragrances causing reactions most commonly included lavender, rose oil, ylang-ylang, geranium, jasmine and sandalwood. The authors say that the problem is likely to increase as the use of plant extracts in cosmetics rises. In addition, the likelihood of patients reacting to plant extracts in cosmetics is probably increased by the "surprising" fact that many essential oils are not classed as fragrances by the cosmetics industry. This is despite the fact that essential oils account for a large proportion of the plant extracts found in products labelled as being fragrance-free. Patients who are allergic to fragrance should be "advised to look for and avoid cosmetics containing plant extracts", they conclude.