The sticky, irritated feeling between your butt cheeks on a hot day is caused by trapped moisture, friction, and heat in a skin fold that doesn’t get much airflow. Treating it comes down to three things: drying the area out, reducing friction, and protecting the skin so it can heal. Most mild cases clear up within a few days once you manage moisture and stop the cycle of sweat and irritation.
Why It Happens
Your gluteal crease is a textbook environment for a condition dermatologists call intertrigo: two warm skin surfaces pressing together, trapping sweat with nowhere to evaporate. The combination of moisture, heat, and constant rubbing breaks down the outer layer of skin, leaving it red, raw, and sometimes stinging. It’s more common in hot weather, during exercise, or if you sit for long stretches, but anyone with skin folds can get it.
Left alone, that damp, irritated skin becomes a hospitable environment for yeast and bacteria. If you notice small raised bumps scattered around the edges of the rash (sometimes called satellite lesions), that’s a sign a fungal infection has set in on top of the irritation, and you’ll need to treat it differently than simple chafing.
Cleaning the Area the Right Way
Regular bar soap is alkaline, which strips away the skin’s natural protective barrier and makes irritation worse. Use a pH-balanced, fragrance-free cleanser instead. Emollient-based soap substitutes work well because they clean gently without drying the skin out further. A no-rinse pH-balanced cleanser is ideal if the area is already raw and painful.
After washing, pat the area completely dry with a clean towel. Don’t rub. If you have a few minutes, let the area air dry before getting dressed. This step matters more than people think: putting clothes on over damp skin restarts the whole cycle immediately.
Keeping the Area Dry
Once the skin is clean and dry, applying a powder helps absorb sweat throughout the day. Cornstarch-based powders are a safer choice than talc-based products. Talcum powder has been the subject of multiple recalls because it can contain trace amounts of asbestos fibers, and inhaling large amounts can cause lung irritation. Cornstarch carries no asbestos risk, though you should still avoid breathing it in during application.
Body powders marketed specifically for this purpose often combine cornstarch with ingredients like kaolin clay or baking soda for extra absorption. Apply a light dusting after drying off, and reapply midday if you’re sweating heavily. Some people find that carrying a travel-size bottle for a midday refresh makes a significant difference, especially in summer or during physical work.
Antiperspirants Below the Belt
Antiperspirants aren’t just for armpits. You have sweat-producing glands in the groin and gluteal area, and antiperspirants can reduce output there too. However, the skin between your cheeks is thinner and more sensitive than underarm skin, so higher-strength formulas carry a greater risk of irritant contact dermatitis. Stick with a standard-strength, fragrance-free formula and apply it to fully dry skin. If you notice burning or increased redness, stop using it in that area.
Reducing Friction and Protecting Raw Skin
Barrier creams create a physical layer between skin surfaces so they slide instead of sticking and rubbing. Creams or ointments containing zinc oxide, petrolatum, or both are the standard recommendation. Diaper rash creams work perfectly for this, even though the packaging isn’t exactly designed for adult marketing. Apply a thin layer to the crease after cleaning and drying.
Anti-chafing balms and sticks serve a similar purpose and tend to feel less heavy than zinc oxide paste. These are especially useful as a preventive measure before exercise, long drives, or outdoor work in the heat.
When a Fungal Infection Develops
If the rash is bright red with defined edges, itches intensely, or has small bumps and pustules spreading outward from the main irritated zone, a fungal infection has likely taken hold. Over-the-counter antifungal creams containing clotrimazole (1% strength) are widely available and effective. Apply a thin layer to the affected area two to three times a day, with three times being more effective. A strip of cream about one centimeter long covers roughly a hand-sized area, so you don’t need much.
Continue applying for at least a week after the rash visually clears, because the fungus can persist in the skin even after symptoms disappear. If there’s no improvement after two weeks of consistent use, the infection may be bacterial rather than fungal, which requires a different approach from a healthcare provider.
Clothing That Actually Helps
Cotton underwear absorbs sweat but holds onto it, keeping the moisture against your skin. Moisture-wicking fabrics like merino wool, modal, and certain polyester blends pull sweat away from the surface and allow it to evaporate. Boxer briefs in these materials reduce both moisture buildup and the skin-on-skin friction that causes the problem in the first place.
Fit matters as much as fabric. Loose boxers bunch up and create new friction points, while underwear that’s too tight compresses the skin folds together even harder. A snug but not constrictive boxer brief keeps fabric smoothly between the cheeks without bunching. If your pants are also tight, especially in the seat, that limits airflow further. Looser-fitting pants in breathable fabrics make a noticeable difference during hot months.
What to Do About Body Hair
It might seem like shaving would help keep things cleaner, but body hair in skin folds actually serves a purpose. It prevents skin surfaces from sticking directly together, which reduces the friction that leads to intertrigo in the first place. Shaving removes that buffer and also creates micro-abrasions that can get irritated or infected in a high-moisture environment.
If you prefer to manage hair in that area, trimming with clippers is the better option. Clipping shortens the hair without affecting the skin surface, so you reduce sweat trapping in longer hair while keeping the protective benefit of some coverage.
Daily Prevention Routine
Once you’ve cleared up the irritation, preventing it from coming back is straightforward. Shower or clean the area after sweating heavily. Dry thoroughly before getting dressed. Apply a light layer of powder or barrier cream. Wear moisture-wicking underwear. Change out of sweaty clothes as soon as possible rather than sitting in them.
On particularly hot or active days, a midday wipe-down with unscented wet wipes followed by fresh powder can reset things. Some people keep a small kit in their work bag or car with wipes, powder, and a spare pair of underwear for exactly this purpose. It sounds like overkill until you try it on a 95-degree day and realize you’ve eliminated the problem entirely.