Dear Dr. Eva,

Every summer I get an itchy rash in my crotch area, sometimes also in my underarms and below my belly. I have been given creams for this, but they only relieve the itch, not the rash and then the itch comes back as soon as I run out of cream. What can I do to get rid of this for good?

Summer Rash


Dear Summer,

The rash you are describing is called intertrigo or intertriginous dermatitis – which is just Latin for irritated skin folds. This can occur anywhere on the body where folds of skin touch and sweat collects. The areas you mention are common; it also occurs below the breasts, in neck folds, behind the knees, behind the ears. The rash is caused by skin irritation from the salt in sweat. Once the skin is irritated and tender from sweat, fungus that normally lives on the skin without causing problems often starts to overgrow, because fungus grows well in moist areas. (Think of mushrooms.) So although intertrigo is often thought of as a fungal (or “yeast”) infection, the underlying problem is skin irritation from sweat (salt and moisture.) Because the main cause is hot weather and sweating, you can see why just treating the fungus infection does not solve the problem.

The way to prevent intertrigo, and to heal it once it starts, is to keep the skin creases dry and wash sweat off often. The best way to do this is to wash the areas where you tend to get the rash twice a day using mild soap and a hand-held shower spray with a flexible hose to rinse skin creases. You can get a shower spray to attach to the shower pipe (replacing the shower head) or the tub faucet for $25. Use cool or warm water for bathing, not hot. Rubbing with a washcloth can worsen the skin irritation, but water spray will not. After washing, dry the skin creases by patting gently, not rubbing. Before dressing, take a few minutes to let the rash-prone areas of your skin dry completely by lying under a fan or using a blow dryer on the “cool” setting while holding the skin folds apart. This process may seem strange, but it is key to keeping the skin dry and healing the rash. After drying, look between the skin folds using a mirror. If there are cracks in the skin or red, tender or oozing areas, put a small amount of two creams onto those areas: an antifungal cream (such as clotrimazole or miconozole) and 1% hydrocortisone. Both are available without a prescription in drugstores and large groceries. It can be helpful to use cornstarch or anti-fungal powder in creases that aren’t currently irritated to help absorb moisture and discourage fungus growth. You also can place a thin piece of paper towel between skin folds to keep the skin from rubbing. Don’t use powders containing talc (talcum powder), because talc particles are sharp and irritate the skin. Talc powder was used in the past on babies’ skin, but it’s no longer recommended. Dress in loose-fitting clothes that do not trap moisture. Underwear, especially, should be cotton and not nylon or other synthetics.

This may sound like a big process, but it quickly becomes routine. You can experiment to find out which of these steps are most important to keep your skin healthy. Once the weather is cooler, your usual skin care may be all you need.

Dear Dr. Eva,

What is summer penis? Is there really such a thing?



Dear Dubious,

Summer penis does exist, even though I cannot find a photo of it to include here. It is redness and swelling of the penis caused by a chigger (a tiny insect) bite on the penis. This happens to boys more often than to adult men. It often starts after a boy has urinated (peed) outdoors in tall grass, where there are often chiggers. Summer penis is itchy, and sometimes there is discomfort with urination. It can last from a few days to a few weeks. Antihistamines are helpful for itching.

If you search the web, you can find the term “summer penis” used to describe the idea that the penis gets bigger in the summer. This does not happen! It is a myth, maybe based on the real observation that the penis skin shrinks in cold weather.

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Dr. Eva Hersh, MD
Dr. Eva Hersh, MD
Eva Hersh is a family physician. Send your comments and questions to her by email at