Dear Doctor: Our summer is filling up with pool and beach activities, and though it’s great that our kids will get exercise and have fun, I’m also worried. The older boys are decent swimmers, but the youngest, who just turned 4, is still learning. How do we keep them all safe?

Dear Reader: Thank you for bringing up an important topic. With the hot (and hotter) weather and carefree summer vibe, water safety may not be the first thing on everyone’s minds. But according to statistics compiled by the Centers for Disease Control and Prevention, drowning is the leading cause of accidental death among children age 4 and younger. It’s the third-most-common cause of accidental death among children and adolescents between the ages of 5 and 19.

It’s great that your older kids can swim and that you’re making sure your youngest is learning. However, swimming skills alone aren’t enough to keep a child safe. As anyone who has spent time around kids at play knows, it’s basically chaos. That makes ensuring their safety around open water a daunting task. But the good news is that the basics of water safety fall into three manageable categories -- barriers, surveillance and education.

The American Academy of Pediatrics recommends -- and some local and state laws require -- that swimming pools be enclosed by a four-sided fence at least 4 feet high, with self-closing and self-locking gates with alarms. When swim time is over, doors facing the pool should remain locked. Let kids swim only in pools with clear water with good visibility, particularly near the dangerous area of the pool drain. At the ocean or a lake, set non-negotiable boundaries for where children can range. This includes not only water depth, but the width of the play area. That lets you create a manageable zone to watch them. An adult who can swim should always stay within arm’s length of any child with poor swim skills.

Vigilant surveillance is crucial. Even in areas with lifeguards, a designated adult should continually monitor kids in the water. No cellphones, no chatting, no daydreaming. As any parent whose child has gotten into trouble in the water can attest, the unthinkable happens in mere seconds. If you’re with other capable adults, break surveillance into shifts. When alone, give kids timed swim sessions. Regularly bring them onto dry land for snacks and sunscreen, and everyone gets a needed rest. Restate the physical limits of their play area each time they return to the water. If someone breaks the rules, the penalty is a non-negotiable return to dry land.

Education includes swimming and water competency lessons, which can begin as early as age 1. Learning CPR makes everyone safer. Studies show that kids as young as 9 can learn and use this vital skill. And learn the signs of drowning, which is actually a quiet event. Speech is secondary to breathing, and a drowning person may only have the ability to gasp for breath and try to stay afloat, and thus can’t cry for help. For information on water safety, visit poolsafely.gov.

(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: My best friend had a successful breast cancer surgery last spring. But the surgeon took out some lymph nodes, and now she’s getting lymphedema in her left arm. Is it true that there’s no cure?

Dear Reader: Lymphedema is the name for swelling that occurs when there is a blockage to the lymphatic system. Often, as in your friend’s case, it arises when lymph nodes are removed or damaged during cancer surgery or treatment. The condition can also be caused by infection, inflammation, injury or certain illnesses. Lymphedema is most common in the arms or legs, but it can occur anywhere in the body in which the lymphatic system is blocked. While there is no cure, recent developments in diagnostic tools offer hope for managing the condition.

The lymphatic system is a remarkable network of tissues, organs, ducts and nodes that collect and disperse lymph, or lymphatic fluid, throughout the body. If you’ve ever scraped yourself and noticed the clear fluid that seeps from the wound, that’s lymph. It’s made up of fats, proteins, white blood cells and cellular waste, and it is an integral part of the immune system.

The lymphatic vessels that transport lymph throughout the body have valves that keep the fluid moving in one direction. But unlike our circulatory system, which utilizes the heart to move blood through the body, the lymphatic system has no central pump. Instead, it relies largely on the movement of skeletal muscles to keep lymph moving. Lymph vessels carry the lymphatic fluid throughout the body and eventually to the lymph nodes -- hundreds of small, round structures that collect the fluid and filter out the waste and bacteria it carries. When enough lymph nodes are damaged or removed, that part of the lymph system is blocked. The result is that fluid collects and causes the swelling known as lymphedema.

The condition can be painful; it can result in tissue damage and infection, and often limits a person’s range of motion in the affected limb. At this time, treatment focuses on managing swelling and pain. This includes the use of compression garments, physical therapy and lymphatic massage, a technique performed by trained specialists to manually disperse the accumulated lymphatic fluid. Strides are also being made in microsurgery, including lymph node transfer and the repair of lymph vessels.

More recently, a diagnostic technique called bioimpedance spectroscopy, which uses an electric current to measure the buildup of extracellular fluid, is seen as a potential advance in the early detection of lymphedema. This is important because the sooner that patients begin lymphedema therapies, the better the condition can be controlled. Last year, small studies into the use of certain anti-inflammatories to manage swelling also showed promise.

(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’s the latest on the new children’s disease that’s kind of like polio? It’s been all over the news, and like a lot of the moms around here, I’m getting worried.

Dear Reader: You’re referring to a rare and serious neurological condition that, as you mention, bears some striking similarities to polio. Known as acute flaccid myelitis, or AFM, it has thus far been seen mostly in children. AFM results in extreme muscle weakness and even paralysis, mainly of the arms and legs. At this time, the leading suspect is a virus that attacks and causes damage to the spinal cord. Unlike polio, which is known to be caused by the poliovirus and for which we have an effective vaccine, the specific cause of AFM is not yet known, and there is no vaccine.

Acute flaccid myelitis is not a new condition, but it has been on the rise in recent years. Due to this steady increase in cases, the Centers for Disease Control and Prevention began tracking the illness in 2014. There have been 570 confirmed cases of the condition since that time, with an average patient age of 5 years. Last year, a total of 233 confirmed cases of AFM occurred in 41 states. This played a role in the CDC’s decision to release an update about the condition in early July, which has put acute flaccid myelitis back into the headlines. The timing of this newest update is due to the observation that AFM has a “season,” with the number of cases spiking in late summer and early fall.

Although cases of AFM are reported each year, outbreaks appear to surge every two years. The CDC reports that so far in 2019, which according to the previous pattern is an “off” year for the condition, 11 cases of acute flaccid myelitis have been reported. However, because awareness of AFM is relatively recent, it’s likely that undiagnosed cases have not made it into the official tallies.

The majority of cases begin with fever and respiratory symptoms similar to a cold or the flu. This is followed by neurological difficulties such as weakness in the arms or legs, a decrease in reflexes, facial weakness, drooping eyelids, difficulty moving the eyes, slurred speech and trouble with swallowing. Occasionally, numbness or pain may be present, and in some cases, patients experience trouble breathing.

A lab test to diagnose the condition has not yet been developed, which makes vigilance by parents and health care providers about potential cases all the more important. Because the later symptoms of the condition can mirror those of other neurological diseases, such as Guillain-Barre syndrome, AFM is difficult to diagnose. There is no known cure, so at this time, treatment focuses on physical and occupational therapy to restore movement.

If your child shows symptoms of AFM, seek medical help immediately. Health care providers whose patients show symptoms of AFM have been directed by the CDC to immediately alert their state or local health departments. They should collect biological specimens to help identify the causes for the condition.

(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.)