Dear Doctors: My uncle tested positive for the coronavirus last winter and wound up in the hospital. He was lucky, and he recovered, but it is six months later and he still is not completely better. He says he’s what’s known as a “long-hauler.” Can you please explain what that is, and why it happens?

Dear Reader: From its earliest days, the coronavirus pandemic put science and medicine on the steepest of learning curves. The virus had never been seen before, and the disease that it causes, now known as COVID-19, was a complete unknown. As months passed and the data accrued, we continued to learn about the many ways that the novel coronavirus affects the human body. We’ve also become aware of the different trajectories that the illness it causes can take. Some people, as we now know, develop only mild symptoms. Others have no symptoms at all. Some struggle with serious or fatal cases of COVID-19, while others experience moderate disease with complete recoveries. But as the number of cases continues to grow, and doctors share and pool their data, a troubling trend has emerged.

Unlike the flu, the disease that in many respects it resembles, COVID-19 is not always a short-term illness. For many people, as with your uncle, recovery becomes a long and uncertain process. A survey conducted by the Centers for Disease Control and Prevention last spring found that up to 35% of COVID-19 patients continue to feel the effects of the disease long after tests show they were virus-free. This appears to be similar to what was seen with SARS (severe acute respiratory syndrome), the coronavirus-caused illness that first emerged in 2002. Some patients who had been hospitalized with SARS continued to experience impaired lung function two years after first becoming ill.

Patients who continue to experience lingering symptoms, now referred to as “post-COVID syndrome,” have come to be known as long-haulers. Unlike the steady recoveries we make from a cold or the flu, long-haulers experience repeated setbacks. A day or two of good health will be followed by a sudden recurrence of fever or lung inflammation. Fatigue, exhaustion, chills and headache come and go and then come again. Some patients find themselves back in the hospital for treatment of acute symptoms. For many long-haulers, the cognitive difficulties that can accompany a severe bout of COVID-19 never completely vanish. And as the disease drags on with no end in sight, a growing number of people with post-COVID syndrome report dealing with feelings of anxiety and depression that interfere with daily life.

As with so many questions related to the novel coronavirus and COVID-19, the causes of post-COVID syndrome are not yet known. One promising line of inquiry is looking at whether viral particles that remain within the body may be setting off powerful immune reactions. Meanwhile, many COVID-19 long-haulers say they are finding emotional safe harbor in online support groups made up of fellow survivors. They exchange information, share strategies and find comfort in knowing that, in this particular long journey, they are not alone.

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

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.)