Psoriasis and Beauty Products: Ten Triggers Dermatologists Warn About

Roughly 25% to 30% of psoriasis patients experience the Koebner phenomenon—new plaques forming at sites of skin trauma—according to frequently cited research. That statistic explains why common beauty products and treatments, from glycolic acid peels to tattoos, can trigger flares in some patients, four board-certified dermatologists told Allure.

Psoriasis stems from immune system dysfunction, not external irritants, so many topical products are safe as long as they do not damage the skin. The risk rises with anything capable of causing trauma.

What is the Koebner phenomenon?

"Local trauma stimulates the immune system to develop psoriasis in the traumatized skin," says Shira Y. Wieder, MD, a board-certified dermatologist at Montefiore Einstein Advanced Care in New York City. New plaques appear on previously clear skin.

"Not everyone with psoriasis has this response, but if you've ever watched a plaque appear at a cut, a scratch, or a sunburn, assume you're someone who does," says Omar Noor, MD, a New York City-based board-certified dermatologist.

Even without Koebnerization, an irritating product applied to visible psoriasis can worsen a flare. "If you have sensitivity [to an ingredient], then, yes, that's going to trigger irritation to your skin, which will result in a flare in your psoriasis," says Divya Shokeen, MD, founder of OSVI Dermatology and Surgical Institute in California. She advises patch-testing every new product.

Treatment status changes the calculus. "If your psoriasis is controlled, especially on a systemic treatment like a biologic, that risk drops substantially, but not to zero," Dr. Noor says.

Which ten products and treatments raise risk?

• High-concentration acids. Dr. Noor advises leave-on products at 5% or less glycolic acid, about 8% or less lactic acid, or up to 10% mandelic acid. Dr. Shokeen warns against L-ascorbic acid at 15% or higher. Salicylic acid is the exception: "It'll get rid of all the scale," Dr. Wieder says. Dr. Shokeen recommends 2% in over-the-counter products, noting salicylic acid exfoliates the top layer so prescribed treatments—steroids, vitamin D analogues such as calcipotriene—penetrate better.
• Chemical peels. "By definition a chemical peel [impairs the skin barrier]," Dr. Wieder says. Medium-depth and deep peels warrant red flags, though she is less concerned for patients well-controlled on biologics.
• Physical exfoliants. Walnut shells, apricot scrubs, and loofahs cause tiny cuts that can seed new plaques.
• Abrasive in-office treatments. Microneedling and certain lasers carry risk. "If you feel like you are flaring, I would avoid the treatment altogether," says Tracy Evans, MD, medical director of Pacific Skin and Cosmetic Dermatology in California. Excimer laser treatments, however, "can be very effective in psoriasis patients," Dr. Noor notes.
• Strong surfactants. "If your soap lathers like dish soap, it's no good because you're treating your skin like a dirty pan," Dr. Noor says, citing sodium lauryl sulfate (SLS). He recommends gentle options such as Cetaphil Gentle Skin Cleanser.
• Fragrance and "unscented" products. Unscented formulas "usually means that the companies are using chemicals to hide the scents," Dr. Noor says. Look for "fragrance-free" instead.
• Pure essential oils. Tea tree oil, peppermint oil, menthol, and witch hazel "can be really inflammatory," Dr. Shokeen says. "Tingling is not good with psoriasis," Dr. Noor adds.
• Lightweight moisturizers. Alcohol-thinned pump lotions dry psoriatic skin; Dr. Noor recommends rich, multi-lipid creams—"nothing that comes out of a pump."
• Hair dyes. Para-phenylenediamine (PPD) allergies create "an inflammatory mess" in psoriasis patients, Dr. Noor says.
• Tattoos. Repeated needle microtrauma can trigger Koebnerization. "I've seen people develop psoriasis in the shape of their tattoo," Dr. Wieder says. Biologics and other systemic treatments can reduce that risk.

What should patients do first?

Get the condition under control before experimenting. "When you have psoriasis you should see a dermatologist," Dr. Evans says. Once treated, "you pretty much can use what you want"—after a patch test.