Dear Doctor: I heard about a place in Australia where there’s suddenly a whole bunch of cases of flesh-eating bacteria. What kind of bacteria is this? Can something like that happen here in the United States?

Dear Reader: You’re referring to an outbreak of a tropical disease called Buruli ulcer, which has been centered along a portion of Australia’s southern coast. The disease is caused by a pathogen known as a mycobacterium. That’s the same genus of microorganisms that cause tuberculosis and leprosy, among other illnesses.

For fellow science nerds, the organism that causes Buruli ulcer is the mycobacterium ulcerans. It’s named for Buruli county in Uganda, which is where scientists first identified the collection of symptoms as a specific condition. The organisms that cause the disease release a unique toxin known as mycolactone. It not only damages the tissues it inhabits, but also is able to prevent the immune system from mounting a defense.

Buruli ulcer usually begins quietly, often with a small and painless raised lesion, a patch of thickened skin or an area of swelling just below the skin. Within the next four or five weeks, the organisms create a wound that, if left untreated, will grow in size. Although damage is usually limited to the skin and the tissues just below the skin, in some cases the bone can be affected. This can lead to deformities. About half of cases of Buruli ulcer are found on the lower limbs, about one-third appear on the arms and the rest develop in other regions of the body. How the disease is transmitted is not yet known.

Even though health care providers familiar with the disease can often make a diagnosis from viewing the damage caused by the microorganism, it’s important to conduct a thorough examination to rule out other potential causes. This includes taking the person’s medical history and learning about all recent travel. Tissues from suspected sores and lesions are gathered, either with a swab or a biopsy, and are then tested in a laboratory. In its early stages, the condition is occasionally mistaken for boils, fatty tumors known as lipomas or a fungal infection. Several of the people in Australia who became infected with the mycobacterium initially thought the resulting nodules were insect bites. The disease is treated with a combination of several different antibiotics and wound care.

Buruli ulcer has been identified in 33 different countries, but historically has been most common in certain tropical regions of west and central Africa. Outside of Africa, the largest number of cases each year are reported in Australia. The number of cases worldwide fluctuates. Reports have ranged from a height of 5,000 cases per year to a low of about 1,900 cases, in 2016. Now, as with the outbreak in Australia, cases appear to be on the rise again. As for whether or not the disease can become a problem in the U.S., it’s unlikely. Only a few cases have been reported here over the years, and each was linked to travel in a region where the organism that causes the disease is regularly 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.)

Dear Doctor: Our city requires face masks now, and we’re not sure what’s the best kind for our kids. Our teen wears an adult mask, but we have a 6-year-old and a 9-year-old as well. Do you have any advice?

Dear Reader: We’ve been getting this question a lot as various state and city lockdowns end and we’re all peeking out from our quarantine bunkers. There’s no question that face masks are a vital tool for a safe reentry into public life. They do a good job at blocking our exhaled breath, which helps prevent the spread of the novel coronavirus in people who are infected. That said, there are a few caveats. Face coverings should not be worn by children younger than 2 years old, by anyone who has trouble breathing, or by anyone who is unable to remove the mask without assistance from someone else.

The best type of face mask for kids is the one that the child will wear. That’s going to be your guiding principle. Don’t worry too much about details such as the type of material the mask is made of, how it attaches or whether or not it has a filter. The bottom line is that if it’s not comfortable, your child won’t wear it properly. They’ll tug and pull at it or try to readjust it. In the process, they’ll wind up touching their faces, which increases the risk of infection. Even with an optimal mask, a younger child may not be able to tolerate it for extended periods of time. If that’s the case, prioritize mask use for situations when social distancing isn’t easy to maintain. Wearing a mask is particularly important indoors, where people tend to crowd together and where the virus can linger.

As for the masks themselves, they are effective only if they cover both the nose and the mouth. Look for one that’s fitted with a flexible clip on the nose piece. That makes it easy to adjust and customize to your child’s face. Avoid masks with a one-way valve. These allow the exhaled air to escape and do nothing to protect the people around you. Choose a mask that fits over the chin and reaches around the sides of the face. Not only will this give a more secure and comfortable fit, it helps cut down on the amount of air that blows out of the mask, rather than diffusing through the fabric.

If your kids are anything like ours, they have definite opinions about what they like to wear. Giving them a say in choosing their own masks can boost the odds that they’ll actually wear them. Look for washable masks made with two layers of breathable cloth. It may take a few purchases to find the mask your kid prefers. Once you do, get at least two masks per child so it’s easy to keep them clean. Teach kids to avoid touching their faces once the mask is on, and to clean their hands thoroughly once it’s removed.

(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: What do you think about yoga for children? We’re having trouble keeping three kids busy without their usual play dates and activities, and our 8-year-old has been saying that she wants to try doing yoga.

Dear Reader: We are enthusiastic supporters of yoga for kids. Just as for adults, yoga can improve children’s physical and mental health. The gentle and sustained poses help with flexibility, strength, balance, endurance, breathing and breath control. Yoga is great for improving focus and concentration, building self-confidence and reducing stress and anxiety. Studies have shown that children with ADHD (attention deficit hyperactivity disorder) experience significant improvement in their symptoms when regular yoga practice is added to their existing treatment.

Yoga has found its way into school settings, but with in-class learning on hold, we now need to bring it into our homes. Fortunately, there are plenty of resources. YouTube has a number of very good channels stocked with yoga videos just for kids. One that we like a lot is Cosmic Yoga, a top-rated series with close to 900,000 subscribers. App stores are also loaded with a variety of kids’ yoga classes. If you’re unsure about which to choose, enter the name of the class or app into your search engine, and you’ll find reviews and opinions to guide you.

The key to yoga for kids is for it to be fun, a tiny bit challenging and stress-free. You’re not looking for the hour-plus classes that adults are used to, with complex poses held for long periods of time. Instead, kids’ yoga is about movement, imagination and playfulness. Yoga poses come with built-in imagery -- lions, dogs, warriors, trees, frogs and butterflies, to name just a few -- which lets kids connect to the exercise on multiple levels. Children really take to the breathing exercises, with blowing and huffing and puffing that lets them add all kinds of sounds. They enjoy a challenge, too. Balance poses, which can start with a few seconds and gradually build from there, are a great way for them to build their skills and feel a sense of achievement.

We doubt that they’ll notice it’s happening, but yoga is a creative and fun way to introduce mindfulness through play. These are stressful times for everyone, our children included. The mix of vivid imagery, deliberate movement and controlled breathing can help children cope with a world suddenly gone sideways. And, thanks to the proliferation of screen-sharing platforms like Zoom, playmates who have been separated can do yoga together.

We’ve been concentrating on the kids so far, but we encourage the adults in the house to get involved, as well. Definitely let the kids have some sessions all to themselves. But when moms, dads, older siblings and grandparents take part, those 20 or 30 minutes of yoga can become a source of family bonding and unity. Plus, kids are competitive. They’ll be tickled pink -- and won’t let you live it down -- when their flexible bodies easily achieve poses that have Mom and Dad gasping and groaning. Their delight will be a victory for everyone.

(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.)