One of the most effective treatments for fungal acne might already be in your shower: dandruff shampoo. That’s right — you can slather the hair-care product on your face and body. I know it sounds wrong, but dermatologists swear it’s oh so right.Why Dandruff Shampoo Works on Fungal AcneTo understand how dandruff shampoo could be an effective treatment for fungal acne, you need to understand what fungal acne is. Although it may look like any other breakout, it isn’t acne at all. “It just plays one on TV,” jokes Mona Gohara, an associate clinical professor at Yale School of Medicine. Clinically known as pityrosporum folliculitis, fungal acne is actually inflammation of the hair follicle due to an overgrowth of yeast called Malassezia, which is caused by hot, humid conditions. “Yeasts are a form of fungus, which can cause dandruff, as well,” Gohara says.Because of this, dandruff shampoos can help treat fungal acne better than cleansers formulated with standard acne ingredients, such as benzoyl peroxide or salicylic acid, because you need to treat the yeast instead of bacteria, Gohara says.Dandruff shampoos are considered anti-fungal treatments as they are spiked with ketoconazole, zinc pyrithione or selenium sulfide, says Jennifer Chwalek, a board-certified dermatologist at New York City’s Union Square Laser Dermatology. Ketoconazole, specifically, “works by disrupting the cell membrane of the fungus, which prevents it from growing and replicating,” she explains. Sulfur, on the other hand, produces pentathionic acid, which is toxic to fungi.How to Treat Fungal Acne With Dandruff ShampooAll you have to do is simply sub in a dandruff shampoo for your cleanser or body wash. Lather it up and wash your skin wherever you’re experiencing a breakout. If it’s on your face, Gohara recommends leaving it on for a minute and singing a verse “from your favorite R&B jam,” before washing it off. “It needs some contact time to work, not just a quick on-and-off situation,” she explains. “I usually recommend this for cleansing in the shower.” For body breakouts on your chest, back, and upper arms, Chwalek says you can rinse the shampoo away after 10 minutes.During active breakouts, Chwalek suggests cleansing with dandruff shampoo daily. “Sometimes in individuals who are prone to recurrences, we recommend washing with it once or twice a week to prevent future flares,” she adds.Courtesy of brandWhich Dandruff Shampoos to UseGohara picks Selsun Blue and ketoconazole shampoo as her top choices. The latter is available in prescription options or over the counter as Nizoral.Chwalek agrees, adding Head & Shoulders’ shampoos to the list.Decant your selection into a small toiletry bottle, like Muji’s PE Tube M, and you’ll forget the shampoo was ever meant for your hair.All products featured on Allure are independently selected by our editors. However, when you buy something through our retail links, we may earn an affiliate commission.Read more about treating acne:Now, see a dermatologist’s day and night routine in action:Follow Devon Abelman on Twitter and Instagram.