Allergic Contact Dermatitis: Topical Preservatives, Part I

J. Desiree Douglas


Dermatology Nursing 

In This Article


The main goal for a patient diagnosed with allergic contact dermatitis is to avoid that specific allergen. Patients should be educated to read the list of ingredients for their body, skin, and hair care products. If the patient sees the allergen, or any of the synonyms listed, he/she should not use that product. For example, if the patient discovers formaldehyde is contained in a shampoo he/she wishs to use, then he/she should seek a safe alternative from the Contact Allergen Replacement Database (CARD) list. When the CARD list is used, it not only takes into account an allergy to formaldehyde, but it considers all the cross-reactors and eliminates those products as well. The end result is a list of products that is completely free of formaldehyde and FRPs (American Contact Dermatitis Society, 2009).

Most body care products now list their ingredients. However, if a product contains less than 500 ppm of formaldehyde it is not required to list formaldehyde in the ingredient list. Some patients have developed dermatitis to formaldehyde levels lower than 500 ppm. In fact, certain cosmetic products with levels of 200–300 ppm have caused dermatitis from short-term use (De Groot et al., 2009).

Attempting to avoid formaldehyde can be challenging. An alarming 77% of patients allergic to formaldehyde were still being exposed to formaldehyde at a followup visit, after being instructed on how to avoid such products (De Groot et al., 2009). Formaldehyde is hard to avoid because it is used in a variety of products. Synonyms for formaldehyde can be listed in ingredient lists and patients may not recognize it. Formaldehyde-releasing preservatives can also be listed under synonyms or trade names.

When dealing with skin care products, repeated open application tests (ROAT) are also helpful. If a patient with formaldehyde sensitivity desires to use a product with a FRP, he/she can test whether the amount of formaldehyde in the product is high enough to cause dermatitis. ROAT involves placing a small amount of the desired product on healthy skin on the volar aspect of the forearm twice a day for 1 week and monitoring for signs of irritation.

Formaldehyde can be found in many household products, but the ingredients of these products may not be listed on the bottle. Patients should be advised to search the U.S. Department of Health & Human Services Household Products Database ( By typing in the name of the allergen in the "Quick Search" box, the Web site will list household products containing that allergen. It is very important to stress to patients that this is a list of products to avoid! Industrial supplies and construction materials also do not list their ingredients.

Formaldehyde can also be used as a textile resin to provide wrinkle-resistant, water-proof, shrink-proof qualities to fabrics. This will be a subject for a future "Focus on Allergens" column in Dermatology Nursing.

In the next issue of Dermatology Nursing, the non-formaldehyde-releasing preservatives will be discussed.