Dermatology Made Easy is based on the most popular topics from DermNet NZ's vast array of material. The book combines the essential focus of the ‘Made Easy’ book series with the authority and knowledge base of DermNet NZ's unparalleled resources.
Author: Vanessa Ngan, Staff Writer, 2002.
Paraben mix is a mixture of 5 different paraben esters; methyl-, ethyl-, propyl-, butyl- and benzyl-parahydroxybenzoate. Parabens are the most commonly used preservatives in topical pharmaceutical preparations. They are also used in cosmetics, skin care products, medications, foods, and industrially in oils, fats, shoe polishes, textiles and glues. Two or more paraben esters are often found in the one product, so it is useful to test paraben sensitivity with paraben mix, as there is a high incidence of cross-reactions between the esters. Benzylparaben is rarely used.
Paraben mix sensitivity produces classic allergic contact dermatitis reactions. Sometimes it may be seen as a flare or spread of an existing treated rash. Paraben allergic hypersensitivity is not uncommon although rare in relation to its widespread use. It appears that repeated applications of relatively low concentrations of parabens in medications and cosmetics may lead to sensitivity. Allergic reactions to orally ingested paraben-containing foods are rare.
Paraben mix allergy is diagnosed from the clinical history and by performing patch tests. Patch testing with 15% paraben mix in petrolatum is used.
Self-testing a product for parabens is possible but should be done only after first talking with your doctor. This should be done only with products that are designed to stay on on the skin such as cosmetics (not including eyeliners or mascaras) and lotions. Apply a small amount of the product to a small tender area of skin such as the bend of your arm twice a day for 1 week. Examine the area each day and if no reaction occurs, you are unlikely to be allergic to it. Even so, you should still be cautious if you are intending to use it over large areas as it may still be an irritant.
Products such as shampoos, soaps and cleansers should not be tested in this way as they frequently cause an irritant dermatitis.
Anyone diagnosed with paraben mix allergy should avoid exposure to paraben-containing products. Once the dermatitis appears on the skin, treatment is as for any acute dermatitis/eczema.
Once paraben sensitivity is confirmed, try to avoid exposure to any products containing paraben preservatives. This can be difficult because of its widespread use across many products. Read product labels and avoid products that contain any paraben preservatives or any of its alternative names. If unsure, ask your pharmacist for advice or a suitable alternative. Other related substances you may also react to include para-aminobenzoic acid (PABA) esters and paraphenylenediamine.
Alert your doctor and dentist to the fact that you have an allergy to parabens. Your dermatologist may have further specific advice, particularly if you are highly sensitive.
Avoid all of these. At work, request a material safety data sheet to help identify potential sources of exposure.
Parabens, chemical formula and CAS number
Sensitiser: paraben esters
Patch Test: paraben mix 15% in petrolatum (3% each of methyl-, ethyl-, propyl-, butyl- and benzyl-parahydroxybenzoate)
Notes: topical parabens have recently been reported to have weak oestrogenic effects leading to concerns about breast cancer. Research is on-going.
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