Research suggests that the biggest culprits are synthetic fabrics like polyester and nylon, which are usually made with cheap dyes that can bleed off. Cotton blends and corduroy are also commonly treated with wrinkle-resistant finishes, says Dr. Chen. Contact dermatitis tends to occur in areas of the body that get sweaty or rub against clothing, such as your armpits, upper back, waistline, or inner thighs. “The clothing that’s going to have more direct contact with the skin is more likely to cause a problem,” she says. (Think: underwear, swimwear, sportswear, or the inner linings of skirts and dresses.)
Many people won’t develop reactions to these irritants if they choose to forgo a first wash, but research finds that textile-based contact dermatitis isn’t uncommon. Dr. Chen’s take: It’s a reasonable precaution to wash your new clothes to rinse off any residue, especially if you have sensitive skin. In her own life, she always washes first: “It’s an easy enough thing to do, and it’s not worth the potential issues” to just wear clothes off the rack, she says.
Clothes are likely swarming with germs.
Dyes and chemicals aren’t the only possible issue. Though it’d be nice to believe your purchases came straight from a sterile (albeit chemical-filled) environment, that’s likely not the case. There’s a solid chance that other shoppers tried on your items first (either in the store or before returning them), or that they were handled by people working in a manufacturing facility, warehouse, or brick-and-mortar store. And if another person touches the clothing, it automatically has the potential to carry all kinds of pathogens, like staph, norovirus, and even bits of feces (see why I’m now pro-wash?). “Man leaves his imprint of microorganisms on whatever he touches—whether it’s a countertop or a piece of clothing,” Dr. Tierno says.
In 2010, Dr. Tierno swabbed a bunch of store-bought clothing for a Good Morning America segment and found all types of germs: respiratory secretions, vaginal organisms, and fecal matter. This shouldn’t come as a surprise, but this is especially a risk with vintage or second-hand clothes. In fact, some research has shown that used garments can be contaminated with the bugs that cause pediculosis (lice infestation) and scabies—no thank you! That doesn’t mean all previously owned clothes are a health issue waiting to happen, but just that it’s worth putting your new-to-you finds through the wash before wearing them, just in case.
This all really depends on the type of clothing, too, says Dr. Tierno: Underwear and bathing suits are more likely than, say, a puffer jacket to contain another person’s flora, the group of microorganisms that lives on each and every one of us, because those items are worn closer to intimate body parts. Some of those germs can survive on dry fabric for a few days; others—like staph or E.coli—can live for weeks and even months on clothing.
Don’t panic, though: The overall risk of getting sick from germs living on your new clothes? “Pretty low,” says Dr. Tierno. Your body is covered in microorganisms that do a pretty good job of protecting you from infectious intruders, he says. But that doesn’t mean the risk is zero—especially for the elderly, people with psoriasis or other skin conditions that can cause cracking or weakening of the skin, and those living with a chronic disease making them more susceptible to getting sick from microorganisms, he adds.
If you ordered your items online and they arrived sealed in cellophane, you’re less likely to come down with something if you jump right into your clothes, says Dr. Tierno. But if you bought the items at a store where people may have touched them or tried them on, it can’t hurt to run them through the wash (ideally, on a hot setting, since heat can kill unwanted germs). “That’s a safe bet, especially when you’re dealing with underwear and things that are not packaged,” Dr. Tierno says.
As for me? Now that I know we’re all “bathed in fecal matter as a society,” as Dr. Tierno told me, I’m gonna hold out until my new outfits have been through the spin cycle. Even if the risk of getting sick from my new yoga pants is low, I’d rather rest easy knowing they aren’t teeming with teeny-tiny bugs.