If you’re the type who dons new digs without washing them first, there’s a chance you may pay a price for it a few days later. A red, itchy, painful price.
Allergic contact dermatitis is an immune system-related reaction to an allergen that has come into contact with your skin. It causes a delayed reaction: a rash that appears a few days after exposure, and then can last for weeks.
“When we see allergic contact dermatitis from clothing, it’s usually from disperse dyes,” says Dr. Susan Nedorost, a professor of dermatology at Case Western Reserve University and director of the dermatitis program at University Hospitals Cleveland Medical Center.
Disperse dyes are primarily used in synthetic clothing materials like polyester and nylon, Nedorost says. And they may be present at higher levels in a brand-new, unwashed article of clothing.
It’s not clear how common disperse-dye allergies are among the general public. But there is one way to limit your risk for bad reactions: “By washing new clothing, you might remove a little extra dye and so have a lower exposure,” Nedorost says.
In very rare cases, taking this step could even prevent the development of a new allergy. If enough of the dye leached onto a skinned knee or other open wound, she says, that could activate the immune system and create a lasting sensitivity.
Allergic rashes aren’t the only health issue associated with clothing chemicals. In a 2014 study, a group of researchers from Stockholm University in Sweden tested 31 clothing samples purchased at retail stores, and that were “diverse in colour, material, brand, country of manufacture, and price, and intended for a broad market.”
They found a type of chemical compound called “quinoline” (or one of its derivatives) in 29 of the 31 samples, and the levels of this chemical tended to be especially high in polyester garments. Quinoline is used in clothing dyes, and the U.S.
Environmental Protection Agency has classified it as a “possible human carcinogen” based on some studies linking it to “tumour-initiating activity” in mice though the agency also states that no human studies have been conducted to assess the cancer-causing potential of quinoline.