Ask the Doctors by Eve Glazier, M.D. and Elizabeth Ko, M.D

Not All Masks Are Created Equal

Hello, dear readers, and welcome back to our monthly letters column. We hope you’re all doing as well as possible during these challenging times. We’ve received even more mail than usual, much of it -- no surprise -- virus-related. We’ll address some of those questions here, and the rest in an extra letters column soon.

-- Many of you have remarked upon the wide variety of facial coverings people are using and wonder if they are equally effective. The answer, unfortunately, is no. Coverings such as bandanas and scarves, which have a loose weave and a loose fit, don’t provide as effective a barrier as masks made of tightly woven fabrics, with multiple layers and a snug fit over the nose, under the chin and around the sides of the face. The goal of a face mask is to block the large droplets generated by a cough or a sneeze, as well as the airborne particles, known as aerosols, that we produce as we speak and exhale. That’s also why, although they are more comfortable to wear, masks fitted with valves are largely ineffective at protecting others from exhaled breath.

-- Speaking of face coverings, we had several questions about water temperature for washing reusable masks. “I always thought it was the soap, not the water temperature, that did the work when washing hands,” a reader wrote. “So why do all the articles say to wash your face mask in the hottest water possible?” You’re correct that it’s the molecular properties of soap that penetrate the fatty lipid membrane of the virus and disable, or “kill,” it. Water temperature doesn’t play a role, except in comfort. Guidelines from the Centers for Disease Control and Prevention recommend that people wash their masks with warm water and detergent. Water has to be very hot -- 140 to 150 degrees Fahrenheit -- to kill a virus on its own. What’s equally important when washing a mask is to dry it thoroughly, preferably in the dryer. Damp cloth gives other microorganisms, such as bacteria and fungus, a place to thrive.

-- In a column about chondrocalcinosis, a painful buildup of calcium crystals within the joint (also known as pseudogout), we mentioned that low doses of an anti-inflammatory called colchicine can be helpful. A reader from Kelso, Washington, wrote to say the medication brought her relief. “I have had this condition in my knees, ankles and even my wrists,” she wrote. “I started taking colchicine and had an immediate easing of pain, which finally went away.” We’re glad to hear that you found some relief from a painful condition. It’s important for readers to note that colchicine is available only by prescription. It can have side effects, and should be taken under medical supervision.

As always, thank you to everyone who took the time to write to us. Even though we can’t respond to each of your letters, we do read all of them. As a reminder, we can’t offer a diagnosis, recommend or comment on medications or provide a second opinion. Many of you continue to ask for copies of previous columns. The complete archive is available at uexpress.com/ask-the-doctors.

(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.)