Dear Doctor: I would appreciate if you would talk a bit about eyelash mites. What are they, and how does someone get them? What is the best treatment to get rid of them?

Dear Reader: Eyelash mites, also known as Demodex mites, are a type of eight-legged parasite. They live in or near the hair follicles on the face and eyes and are found primarily near the eyelashes and the eyebrows. They have a short life cycle, about 14 to 18 days, during which they feed on the oils and dead cells that are found on the surface of the skin. At about three-tenths of a millimeter in size, Demodex mites are invisible to the naked eye. Under a microscope, however, you would see a semi-transparent body shaped somewhat like a cigar. Their eight legs are arranged in four pairs, which makes it easier for them to grasp tubular structures like an eyelash or an eyebrow hair.

It may be unsettling, but we all have a small number of these mites living in the folds and along the edges of our eyelids. They stay hidden in the hair follicles during the day and emerge at night to eat, lay eggs and excrete waste. The mites are part of our body’s natural microbiome, and by cleaning up dead skin cells and excess oils, they’re actually doing us a service.

As long as their numbers stay low, Demodex mites are harmless. But certain conditions, such as a blocked oil gland, which gives them an abundance of food, can cause the mites to reproduce in great numbers. Their populations also tend to increase as people age. When too many of these tiny parasites are present, they can lead to eye and skin problems. The most common is an inflammation of the eyelids known as blepharitis, or, more specifically, anterior blepharitis. When caused by mites, the condition occurs at the front edge of the eyelid, where the eyelashes emerge. Symptoms include red or dry eyes, swollen eyelids, sticky lashes, itching, burning or stinging, grittiness in the eyes and crustiness around the outer edge of the eyelid. An infestation of mites can also cause dry and itchy skin, and it can even damage the oil glands at the edges of the eyelids and the lashes.

To determine if blepharitis is being caused by eyelash mites, your health care provider will use a special magnifying instrument to examine the eyelid. They may also take a skin, oil or eyelash sample to examine under a microscope. Treatment of anterior blepharitis due to eyelash mites includes gentle and careful soaking and cleaning of the affected area, done several times per day. You may also be prescribed a medicated cream that will trap the mites and prevent them from mating. Throw away any eye makeup you may have used during the infestation. And, since they can spread from person to person, it’s important to never share eye makeup, particularly mascara. Infestations of eyelash mites can recur, so remain vigilant about eye hygiene in the future.

(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 saw on the news that there’s a new study about how to make a successful New Year’s resolution. My wife and I have the same list of resolutions every year, including to stop eating so much junk food and to quit sugar. And around this time every year, we give up on them. We would love to know why it’s hard to follow through.

Dear Reader: It wouldn’t feel like the start of a new year if we weren’t hearing from readers about their love-hate relationship with resolutions. On one hand, the calendar hands you a clean slate. It arrives after weeks of festivities during which overindulgence has been a guiding principle. We’ve eaten and drunk our fill, and we now find ourselves not only ready, but even eager, for a reset. On the other hand, we’re still the same people we were before Thanksgiving signaled the start of the annual bingeing season. All of the reasons we didn’t lose those 10 pounds last August, or didn’t quit our sugar habit in March, still hold true.

Research into the topic of New Year’s resolutions finds that many of us fall off the wagon surprisingly soon. An analysis of the online activity of more than 31 million people suggests that by the end of January, many resolutions are already in the rearview mirror. More rigorous studies from the University of Scranton tracked the slow decline of resolve. By the end of one week, researchers found that 23% of the study participants had already abandoned their resolutions. After three months, half had called it quits. When the researchers followed up two years later, about 20% of participants said they had been successful at keeping their resolutions.

In the study you’re asking about, published last December in the journal PLOS One, the researchers looked at what separated the people who managed to keep their resolutions from those who didn’t. They found that how someone states their goal can make a difference. People whose goals were of the “I will” variety had a higher rate of success than those who approached their resolutions with “I won’t.” Specifically, 59% of the 1,066 study participants with proactive goals considered themselves successful, while only 47% of those with avoidance-oriented goals felt they had succeeded.

In terms of your resolution to eat less processed snack food and to cut down on sugar, you might try flipping the focus. Instead of thinking in terms of what you’re going to eliminate from your diet, try making a specific decision about something that you will add. For instance, you might start with the resolution to eat one piece of fresh fruit at each meal. You can up the ante by agreeing that, before indulging in any kind of snack food, you first have to eat something good for you, like a fresh carrot. That way, even if you do waver in your resolve and slip into old habits with a bar of chocolate or a bag of chips, you’ve also kept your resolution. Change is hard, and even small victories can make it easier to stay on track.

(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: Your column about long-haul COVID-19 started a conversation at our house about why some viruses will keep getting you sick even after you’ve recovered. A friend of our family is having a hard time with something called post-polio syndrome. Is that the same kind of thing?

Dear Reader: You’re not alone is seeing the similarities between long-haul COVID-19 and post-polio syndrome. We recently heard from a reader in Bucks County, Pennsylvania, who wrote to say that people with post-polio syndrome have great empathy for COVID-19 long-haulers and understand the challenges that these people face.

As a recap, long-haul COVID-19 refers to the ongoing adverse health effects of coronavirus infection, which can last for weeks, and even months, after the initial phase of their illness has passed. Symptoms include persistent fatigue or exhaustion; ongoing shortness of breath; heart arrhythmias, including a racing heartbeat; pain in the muscles and joints; and headache. Many patients report difficulties with concentration and memory, which they refer to as “brain fog.” Some experience uneven recoveries in which they appear to be on the mend but relapse into illness again.

Post-polio syndrome, by contrast, arises years later, usually a decade or more after the initial illness. The condition makes itself known with a gradual weakening of the body as a whole, and of the specific muscles and muscle groups that had been previously affected by the polio infection. In some cases, the muscles may also begin to atrophy, or decrease in size. Physical changes to the joints may also take place. Some people experience trouble with breathing, become sensitive to hot or cold temperatures, and may develop sleeping disorders.

Both long-haul COVID-19 and post-polio syndrome occur only in a subset of survivors. There are believed to be about 300,000 polio survivors in the U.S., and from one-fourth to one-half of them may experience some degree of post-polio syndrome. Long-haul COVID-19 is so new that we don‘t yet know how often it occurs, but it may be as many as 20% of patients with COVID-19. People with either syndrome may experience only mild symptoms, or they can find themselves dealing with what is essentially a new and ongoing illness.

As for why these viruses continue to affect people after the initial infection has passed, the answers are not yet clear. When it comes to post-polio syndrome, one theory suggests that the patient’s recovery from the initial paralysis involved the regrowth of new nerve pathways, which then become overtaxed as the years pass. Newer thinking suggests that the polio virus may go dormant within the body, and then, for reasons that are not yet understood, reactivate years later.

With long-haul COVID-19, new research from scientists at the University of California, Davis, suggests that the ongoing respiratory and cardiac effects arise from lung damage sustained during the initial illness. In relapsing cases of COVID-19, it has been theorized the immune system is continuing to encounter fragments of the virus and mounting a defense that results in another round of symptoms. The hope is that, as research continues, effective treatments for long-haul COVID-19 will be found.

(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.)