If you have an allergic reaction to polyester, the clothes you wear, the linens on your bed and the upholstered pillows on your couch could cause an itchy rash. Although polyester allergies to fabrics are unusual -- toys with polyester hair or fur are more typical allergens -- they do happen.
Allergic reactions occur when a harmless substance such as nickel, strawberries or polyester triggers a state of high alert in your immune system. This immune overreaction expresses itself as redness, hives and itching. Contact dermatitis typically appears within a few hours of exposure to the irritant and fades within a few hours to a day after removing the irritating substance from the environment. While some contact dermatitis is allergenic, other forms result from chemical or mechanical irritation. Your doctor can determine the difference between a true allergy that arises from your immune system's response to perceived danger and non-allergic contact dermatitis, a rash that occurs from topical irritation.
Finding the Cause
It's logical to conclude that an itchy rash that appears wherever a polyester garment touched your skin means a polyester allergy. However, the polyester itself might not be the culprit. Polyester resins can cause allergies, but so can detergents, fragrances, fabric softeners, perspiration, animal hairs that become trapped in the fabric's weave and treatments on natural fabrics. If you've recently made a change to your laundry products or soap before the rash occurred, try switching back to products that you used before. Your doctor can also test you for allergic reactions to polyester and other household materials, but this process might take some time.
Polyester Vs. Natural Fibers
While natural fibers themselves rarely cause contact dermatitis, their irregular shapes leave room for dust mites, pollen and other allergens to become trapped in the fabric. Pure cotton wrinkles easily, so manufacturers might treat the fibers with formaldehyde resins that could provoke an allergic reaction. Polyester's smooth fibers shed dust and pollen readily, but the polyester itself might be an irritant to your skin. Pure silk, linen, wool and denim rarely receive treatment with resins, so these natural fabrics are free of both polyester and polishing agents that could irritate your skin.
Toys and Textiles
In his book "Biophysical Therapy of Allergies," Peter Schumacher refers to polyester allergies as "toy asthma" or toy allergies because the reaction is so closely associated with polyester in toys. Certain types of polyester appear likelier than others to cause allergic reactions. According to Schumacher's research, the thin fibers of brushed polyester, such as doll's hair or plush faux furs, are more allergenic than woven polyester fibers. In most cases, this allergy expresses itself as respiratory discomfort, but contact dermatitis is a possibility as well.