Dear Doctor: I’m a 74-year-old male with a stubborn case of jock itch. I’ve tried every over-the-counter ointment, powder and soap, with no success. A prescription cream keeps it from getting worse, but it doesn’t stop the problem. Do you have any other recommendations on how to treat this?

Dear Reader: Jock itch is a topical infection that can be caused by keratin-loving fungi known as dermatophytes, and by a yeast known as candida. Also known as tinea cruris, jock itch is a red, scaly and very itchy rash that appears in areas of the body that stay warm and moist. It gets its name because it’s common in athletes, and also from its location in the area of the groin and inner thighs. It’s more common in men than in women, and it can also arise in people who perspire freely, individuals who are overweight and people with a weakened immune system.

The battle against jock itch takes place on two fronts. One is the use of antifungal medications. This includes the drug store creams, lotions, soaps and powders that you have tried, and a small number of prescription medications. Most people do have success with over-the-counter treatments. More persistent cases of jock itch can call for a prescription for topical medications, including oxiconazole or econazole, or an oral medication, such as fluconazole or itraconazole. If you haven’t had success with topicals, ask your health care provider if an oral treatment might be the next step.

It’s important to understand that medications are only a start. Just as important is eliminating the environment that allows fungi to flourish. That means a thorough and sustained campaign to keep the affected areas very clean and very dry. And by sustained, we mean remaining vigilant from now on. Meds can ease a fungal infection in the short term, but you now know you’re susceptible to this type of condition. That means keeping the affected areas clean and dry will become part of your daily routine. If not, recurrences of the condition are likely.

We recommend that our patients who are dealing with jock itch also use a barrier method, like Butt Paste or Desitin, which are zinc oxide-based creams. Something else that has proved effective, particularly in humid climates where getting completely dry is a challenge, is using a blow dryer. Put it on the lowest heat setting so you don’t risk burning yourself, and use it to remove all residual moisture. That, along with the barrier cream, will eliminate the environment that fungi crave. You’ll also want to start wearing loose-fitting clothing, including underwear, to allow maximum air flow. And be vigilant about washing your hands, which can transfer the fungi. Also, be aware that it can take a month, or even longer, to vanquish a case of jock itch.

If your condition persists despite meds and proper hygiene, you may not actually have jock itch. Other conditions, such as lichens planus, can present with similar symptoms. We recommend that you seek out a board-certified dermatologist to make sure you’ve received an accurate diagnosis.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: I recently fainted in my kitchen and later learned it was because I was dehydrated, something I knew nothing about. I’m well into my 80s and in good health, but I never seem to get thirsty. How much should I drink? Can other liquids take the place of water?

Dear Reader: You’ve brought up an important topic that doesn’t get a lot of attention. That is, the risk of dehydration in older adults.

Our bodies are up to 60% water, so proper hydration is essential for all of us. The water in our bodies serves as a transport vehicle for nutrients and waste, it’s a medium for countless chemical and electrochemical reactions, it acts as a lubricant and a shock absorber, it helps to regulate blood pressure and it plays a key role in regulating body temperature.

Dehydration can cause an array of problems, including dizziness, weakness, cognitive impairment, heart arrhythmia, urinary tract infections and other serious conditions. Severe dehydration is a medical emergency.

Several factors put older adults at greater risk for dehydration than those who are younger. You’ve already mentioned one of them in your letter, which is that you never seem to get thirsty. This is due in part to physiological changes associated with aging, which alter the body’s electrolyte balance and mute the sensation of thirst. Changes to cognition can also lead to an impaired sense of thirst. Certain medications, including diuretics and laxatives, can accelerate fluid loss. And because we lose muscle mass as we age, older adults tend to have smaller fluid reserves.

Older adults must make a deliberate effort to stay adequately hydrated. The actual amount of water needed is up for debate. The often-repeated advice that we should drink six to eight 8-ounce glasses of water per day is not based on scientific findings; the amount of water someone needs actually varies from person to person. Body weight, activity level and even the daily weather play a role. The needs of an active person outdoors in a warm climate will be different from those of a sedentary individual spending time inside.

Many foods -- most notably fruits, vegetables and leafy greens -- contain water that contributes to hydration. So do the coffee, tea and fruit juices we consume.

Considering your run-in with dehydration, it would be wise to check in with your health care provider for guidance on your daily water needs. Until then, as someone who is in good health, the recommended six or eight glasses per day are a reasonable goal. (Individuals living with heart or kidney problems who have to monitor fluid intake must check with their doctors for the safest way to get the fluids they need.)

Water, which has no added sugars and zero calories, remains the best option. You can bump up the flavor with lemon, lime or a slice of cucumber. As we mentioned earlier, tea and coffee do count. We urge you to steer clear of sodas, including artificially sweetened ones. The important thing is not to try to fulfill your quota all at once, but to consume fluids gradually throughout the day.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: I’m not sure you’ll take this question because of the subject matter, but it seems pretty important. Our dad had a fecal transplant as a last-ditch treatment for C. diff, and it worked. Now I’ve read they’re finding other uses for the procedure. Can you talk about that?

Dear Reader: We think you’re correct on both points -- that talking about fecal transplants gives some people pause, and that recent research into this treatment is opening up a new world of therapeutic potential.

For those who are unfamiliar with the concept, a fecal transplant is a procedure in which the stool of a healthy individual is introduced into the gastrointestinal tract of someone who is ill. Although the first modern use dates back to the late 1950s, it’s only in the last decade or so that fecal transplants have gained widespread acceptance.

At this time, the procedure is used almost exclusively to treat Clostridioides difficile, or C. diff, a bacterium that causes severe and sometimes life-threatening diarrhea and colitis. The collection of bacteria contained in the healthy stool restores balance to the patient’s colon, thus defeating an often-intractable C. diff infection. It’s important to note that donors for this procedure undergo careful screening, and the stool itself is specially processed. This is a treatment that should be done only by trained medical staff and in a hospital setting.

As research continues to reveal how the trillions of bacteria, yeasts, fungi and viruses that make up the gut microbiome are tied to our health and well-being, scientists have begun looking at other therapeutic uses for fecal transplants. A new study in mice suggests that a fecal transplant from a mother can help protect a newborn who is at risk of developing Type 1 diabetes due to treatment with antibiotics. Researchers in Australia are enlisting individuals living with Parkinson’s disease to take part in a medical trial to see whether a fecal transplant can alleviate constipation, a common and challenging symptom of the disease. In the United States, clinical trials are underway to study how fecal transplants can help ease certain symptoms of inflammatory bowel disease, colitis and multiple sclerosis.

Most recently, a study about the potential use of fecal transplants to ease some of the adverse effects of aging has gotten a lot of press. In that study, researchers found that when they transferred stool from young and healthy mice to older mice, the recipients had improved cognition -- including better memory -- and exhibited some physical rejuvenation as well. In a previous study that reversed the order of the fecal transplant -- from older mice to younger ones -- the researchers noted that recipients’ cognitive function declined.

Whether due to illness, disease or the effects of aging, the composition of an individual’s gut microbiome can shift to include unfriendly microorganisms that drive inflammation and have a negative effect on metabolism. These studies are exploring whether an infusion of healthy bacteria to recolonize the gut can have a beneficial effect on the immune system and on metabolic function. It’s an exciting and, as you said, important area of study. Imagine the possibilities if the answer turns out to be yes.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)