Hello, dear readers, and welcome back to our monthly letters column. After a winter of wild weather, spring is fully here. That means many of us are heading outdoors. Please play it safe and remember to guard against the sun with hats, long sleeves and sunscreen, and to ease back into physical activities. Balmier weather means ticks and mosquitoes have begun to emerge, so don’t forget the bug protection as well. And now, onward to your letters.

-- We recently wrote about intriguing new research that suggests cases of the common cold and the flu spike in winter weather because of the inner workings of the human nose. Specifically, that a crucial first-line immune response becomes less robust when cold weather causes the temperature inside the nose to drop. This led a reader to ask about specifics. “It's not clear how long it takes for cold weather to cause this effect,” he wrote. “That answer might explain the folk knowledge axiom that getting ‘cold and wet’ has brought on a cold.” That’s a very interesting thought. Folk wisdom does, indeed, connect becoming chilled with an increased risk of catching a cold. But when it comes to this new “cold nose” theory, a lot of variables are at play. These include outdoor temperature, breathing rate, the state of the person’s immune system and -- it sounds funny but it plays a role -- the size of their nose. That makes it difficult to identify the precise length of time it takes for immune response to drop.

-- When someone develops an unfamiliar disease or condition, figuring out who to consult can be confusing. We recently heard from a reader facing that dilemma. “I have been diagnosed with CIDP,” they wrote. “Which doctor should I be seeing -- an internist or a neurologist?” CIDP refers to a neurological disorder known as chronic inflammatory demyelinating polyneuropathy. It is marked by progressive weakness in the arms and the legs, along with a decrease in sensation in the affected limbs. CIDP occurs when the myelin sheath, which is the fatty coating that insulates the neurons, becomes damaged. If you've been diagnosed with this disease, a neurologist should oversee your care. In addition to medications that focus on the immune system, treatment includes physical and occupational therapy and the use of orthotic devices. CIDP requires long-term treatment and management. The National Institutes of Health recommends the GB/CIDP Foundation International as a useful resource. You can visit the website at gbs-cidp.org.

-- Several readers have recently written to ask about shampoos for scalp psoriasis. Medicated shampoos, which can ease symptoms such as itchy, scaly and flaky skin, are widely available at your local drugstore. These typically contain coal tar, which impedes skin cell growth and aids in shedding dead skin cells, or salicylic acid, which helps to soften and remove scaly patches. Be willing to experiment, as it can take trial and error to find the brand that works best for you.

Thank you, as always, for your questions, comments and letters of encouragement. We love hearing from you.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctors: My wife was diagnosed with a C. auris infection while she was in a long-term care hospital. When she gets discharged, will she be able to hug her grandkids, or should she refrain from having any type of close or skin-on-skin contact?

Dear Reader: You’re referring to Candida auris, also known as C. auris. It is yeast, which, along with molds and mushrooms, belong to the group of organisms known as fungi. If part of the name sounds familiar, that’s because C. auris is one of several species of Candida that can cause infections in people.

Known as Candidiasis, it is the most common type of fungal infection worldwide. Various species of Candida cause conditions that, in the majority of cases, are minor and nonfatal. These include athlete’s foot, oral thrush, nail fungus, ringworm and vaginal yeast infections. But if these fungi enter the bloodstream, they can cause serious, invasive and potentially life-threatening infections.

C. auris infections are particularly challenging for several reasons. One is that this species is multidrug-resistant. And with only three effective antifungal drugs available, it makes these infections difficult to treat. At the same time, C. auris spreads easily and widely in the environment and survives even the most stringent infection control measures. It can colonize in the fabrics used in clothes and bedding and has been found to persist for at least 28 days on the hard plastic surfaces common in health care settings.

This pathogen is rapidly spreading through hospitals and long-term healthcare environments. People with weakened or compromised immune systems and preexisting illnesses are most vulnerable to infection. C. Auris can enter the bloodstream wherever there is a breach in the skin. This can be through a scrape or wound, or via an IV, a catheter or other tubes that enter the body.

Patients who have been hospitalized for a long time, or who have previously been treated with antifungal medications or antibiotics, appear to be at increased risk. Due to the rapid spread of C. auris, the Centers for Disease Control and Prevention announced in March that it has labeled the organism an urgent emerging threat for antibiotic resistance. The institution also announced enhanced measures to track and trace infections.

In addition to all of this, C. auris can also colonize in the epidermis. It finds a home and multiplies in the folds and creases of someone’s skin. This can cause the individual to become a carrier. They can unknowingly spread the multidrug-resistant fungus, both to other people and to new environments. That makes your question about your wife’s return from the health care facility both very important and quite complex.

The guidance regarding her actions will depend on specific factors. These include your wife’s health at the time of her release, the status of her C. auris infection and the ages and health of the people she will potentially be in contact with.

That means that any answers about hugging and other types of skin-to-skin contact can only come from your wife’s medical team.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctors: I started running a year ago to deal with stress and to get in better shape. Instead of a set distance, I do 15 minutes of mixed fast and slow running twice a day. But a friend says unless you’re always trying to go farther and faster, it’s not really helpful. Is that actually true?

Dear Reader: We’d like to begin by congratulating you on starting a fitness regimen and maintaining it. The day you took your first run, you started to make an investment in your future health and well-being.

Exercise is a frequent topic in the letters we get, and we have often discussed the wide range of physical, mental and emotional benefits that being active can confer. These include a lower risk of developing high blood pressure, Type 2 diabetes, cardiovascular disease, stroke, obesity and metabolic syndrome. Exercise has also been linked to a lower incidence of certain cancers. And your turning to exercise to help manage anxiety is spot-on. Numerous studies, as well as a wealth of anecdotal data, correlate regular workouts with improved mental and emotional health. This includes issues such as stress, poor mood, depression and anxiety.

The more-is-better philosophy that your friend is urging you to adopt has certainly been popular in the past. However, exercise that is too long or too intense can lead to overuse injuries. There is also some evidence that it may contribute to chronic inflammation.

Meanwhile, a recent body of research suggests that shorter workouts, such as the ones you have added to your daily routine, may be more beneficial than extended ones. In fact, studies show even two-minute bursts of intense exercise, such as powering up a few flights of stairs, or sprinting the last few hundred yards to a destination, are associated with measurable health benefits. It’s not the duration of the exercise that matters in these instances -- it’s the intensity. This type of exercise has been shown to be quite effective at helping to build muscle and bolstering the cardiovascular system.

The current exercise recommendations for adults are 150 minutes of moderate activity -- or 75 minutes of intense activity -- per week. For kids and teens, it’s one hour per day. Add up your twice-daily runs, and you’re exceeding those standards.

Rather than making any changes to the running portion of your workouts, it would be useful to consider expanding into other areas. Aerobic exercise is just one part of a well-rounded program. Weight-bearing exercises to build muscle, as well as stretching exercises for flexibility, are also important. Taken together, these three forms of exercise help to maintain and improve strength, balance, agility and stability.

Turning daily exercise into a long-term habit can be a challenge for many people. This is particularly true when you’re first starting out. In following a running program that you find to be manageable, comfortable and enjoyable, you have created a workout that you’ve been able to stick with for a year. That qualifies as the best type of exercise of all.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)