Dear Doctors: I've read your column for years but have yet to see anything about my problem. I tend to sweat a lot, not under my arms, but in my crotch area. It’s embarrassing and even causes me to get a lot of UTIs. I've tried panty liners and medicated powders, wear only cotton underwear, but nothing works. I'm so frustrated. What can I do?

Dear Reader: Excessive sweating that isn’t a response to either heat or exertion is known as hyperhidrosis. When sweat glands are overactive in one specific location, it’s referred to as focal hyperhidrosis. The condition is believed to arise from overstimulation of the sweat glands by the autonomic nervous system, although why this occurs is unclear.

Excessive sweating in the armpits and around the head and face are the most common types of hyperhidrosis. The folds of skin beneath the breasts are another area of focal hyperhidrosis. Although less common, sweating in the area of the groin is a problem for many women. Researchers recently conducted a survey of close to 2,000 adults who are registered users of the International Hyperhidrosis Society website, found at sweathelp.org. In that survey, 43% of respondents reported experiencing excessive sweating in the groin area.

Our bodies use sweat to stay cool. When certain physiological signals let the brain know the body is at risk of exceeding its optimal temperature range, they direct the sweat glands to release moisture. This results in an evaporative effect, which helps to cool the skin and regulate temperature. And while sweating in the crotch area is a normal function of this cooling system, sometimes the signals go awry.

Some women find relief with topical antiperspirants. These use chemical compounds to temporarily plug the pores through which sweat exits and reduce the amount of moisture that is released. However, antiperspirants can be irritating to delicate skin and tissues, and they should be kept away from the vagina.

Two therapeutics, which have been approved by the U.S. Food and Drug Administration for excessive underarm sweating, are finding off-label use in other types of focal hyperhidrosis. One, a prescription medication called Qbrexza, is a premoistened towelette saturated with a medication. It is applied once daily to the affected skin. Also approved for excessive underarm sweating is Botulinum toxin A, more widely known as Botox.

Some physicians are reporting success with off-label uses of these medications, including for hyperhidrosis in the crotch area. However, it’s important to understand that neither of these medications are FDA-approved for hyperhidrosis in any region other than the underarms. When it comes to Botox, the amount of the drug required for the crotch area can make the treatment quite costly. It’s also very important that the physician providing the treatment is well-versed in the specific injection strategies that are being pioneered.

If you haven’t already, please consult with your health care provider. They can help you with strategies to lessen the incidence of UTIs and other infections. They can also offer guidance if you choose to pursue other options.

(Send your questions to askthedoctors@mednet.ucla.edu. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctors: We’re in central Oregon, and even though the wildfires aren’t right next to our town, we’ve had bad air quality all summer. My husband and I and our kids are feeling irritation in our lungs and sinuses, like when you’re catching a cold. Can this happen even when you’re not close enough to see the smoke?

Dear Reader: The numerous wildfires in the western United States this season have created dangerous conditions far from the reach of the flames. You don’t have to be able to see or smell the smoke for it to present a health hazard. The danger from wildfire smoke comes from the billions of particulates that it contains. As the smoke rises, these minute particles become suspended in the air, where they can drift for many miles. This year, scientists were startled to discover that pollution from the West’s multiple wildfires reached the jet stream, which carried it across the Atlantic Ocean to Europe.

Wildfire smoke is a mix of gases created by combustion and the fine particles that those gases contain. The particles come from everything that has been incinerated, including homes, vegetation, trees, plastics, polymers, chemicals and the host of other materials in our built environment. The particulates carried by wildfire smoke make breathing more difficult for everyone. This is especially true for people living with respiratory problems such as allergies, asthma and chronic obstructive pulmonary disease, also known as COPD, whose airways are chronically inflamed. This leaves them especially vulnerable to the effects of outside irritants.

One of the reasons wildfire particulates are potentially so damaging is their tiny size. They’re measured in microns, with 1 micron about 1/70th the width of a human hair. Particles that small can travel into the deepest recesses of the lungs. There, they cause the immune system to set off a protective inflammation response, which interferes with normal breathing.

Symptoms from inhaling wildfire particulates can include coughing, wheezing, sneezing, throat irritation, itchy or watery eyes, a runny nose, congestion, chest discomfort and shortness of breath. Some people report that it feels like having a mild to moderate flu, but without fever or body aches. Smoke can also be dangerous for people living with chronic heart disease, and can result in symptoms such as rapid heartbeat, chest pain and exhaustion.

To protect yourself and your family, keep track of the air quality in your immediate area. Whenever it drops, take steps to minimize exposure. Stay indoors and keep the windows and doors closed. If your home has either air conditioning or a HEPA filter, use them. Safeguard your indoor air quality by avoiding the use of candles or aerosol sprays. Don’t kick up indoor particulates through activities such as vacuuming or dusting. Everyone, of any age or state of health, should avoid unnecessary exertion. Individuals who use a rescue inhaler should have one available, as well as a spare. Check regularly to see whether anyone is experiencing adverse symptoms, and be willing to seek medical help if it should be needed.

(Send your questions to askthedoctors@mednet.ucla.edu. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctors: My husband caught a cold this summer, and he swears the readings from his fitness tracker a few days before warned him that he was about to be sick. Do you think that’s really possible?

Dear Reader: Your husband’s observations about how changes in the data from his fitness tracker preceded the onset of a cold actually dovetail with the findings of a study that were published at the start of the year. And it’s not the first research of its kind to make the connection. With millions of people now using fitness trackers, scientists are diving into the trove of uploaded data to see what the details may be able to reveal about public health.

For anyone unfamiliar with fitness trackers, they’re wearable sensors, much like a wristwatch, that measure a range of activity and health metrics. Depending on the device -- there are dozens of different brands and types -- fitness trackers measure steps taken, total mileage, speed, direction, elevation climbed and duration of activity. On the physiological side of things, they can track heart rate, heart rhythms, skin temperature and minutes of sleep. Some manufacturers even claim that, using motion sensors and algorithms, their models can map how long someone spends in the various stages of sleep. (Full disclosure: Many sleep specialists are skeptical about the accuracy of the sleep-stage results.)

In a recent study, researchers from the Scripps Research Translational Institute analyzed data collected from the fitness trackers of 47,000 adult women and men. Using a minimum of two months’ worth of readings taken over the course of two years, which included activity, heart rate and sleep, the researchers found that their predictions of regional flu outbreaks matched the statistical data collected by the Centers for Disease Control and Prevention during those same time periods. An earlier study, published by researchers at Stanford University in early 2017, had come to similar conclusions. In that study, the scientists collected 250,000 daily readings from just 43 individuals over the course of a year. The participants wore a range of biosensors, which collected information about daily activity, heart rate, oxygen saturation levels, skin temperature and sleep data. They even tracked exposure to radiation, such as the X-rays and gamma rays encountered in air travel.

As with the Scripps study, certain changes to the readings collected by the wearable sensors predicted coming down with a cold or the flu. These changes included persistent increases in resting heart rate, which were coupled with increases to daily sleep. One of the Stanford scientists, who was also a participant in the study, noticed he had an increased heart rate and a decrease in blood oxygen saturation. It turned out that he didn’t have a cold; instead, the data from the eight different biosensors he was wearing for the study led to an early diagnosis of Lyme disease, before any other symptoms of the condition had appeared.

It’s a fascinating line of inquiry that, no surprise, is getting additional study. In the meantime, listen to your body, stay home if you think you’re getting sick and, please, get your flu shot.

(Send your questions to askthedoctors@mednet.ucla.edu. Owing to the volume of mail, personal replies cannot be provided.)