DEAR DR. DONOHUE: I am 9 years old. I read what you said about dust mites. I am wondering if they can hurt me. Will they affect me in any way? Am I safe around them? One night I was snuggling my pillow pet, and my mom said, “Remember, it has dust mites.” She gave me your article. I couldn’t sleep that night, knowing that loads of dust mites were crawling around me.

So tell me. Should I be afraid? What makes them go away? What will happen? — T.M.C.

ANSWER: Have no fear, T.M.C. Dust mites have not done, are not doing and will not do anything harmful to you. I have them too. So does just about everyone. They’re all over the world. They’re less than one-hundredth of an inch, barely visible. They don’t bite you. They feed on dead skin that has fallen off the body. They don’t crawl in and out of your mouth, as the letter writer suggested.

Dust mites don’t give you any illness, although some people are allergic to them and itch when exposed to them. In a very few people, they might trigger an asthma attack. None of this has happened to you or me. I don’t think it ever will.

Dust mites need high humidity to survive, around 70 percent. You can cut down on their number if you keep your room humidity lower than that.

Don’t try to get rid of them. They’re part of the biological diversity that exists in our world. I don’t know if they do us any good, but they don’t do us any harm, aside from the allergy thing. Sleep in peace. I apologize for ruining a night’s sleep for you

Please don’t ask me about bedbugs. They don’t make people ill either, but they give me the creeps.

DEAR DR. DONOHUE: I have faux gout. At least that’s what I’ve been told I have. It’s in my left foot. I understand it’s not caused by uric acid but by calcium. Can you tell me more about it and what can be done for it? — C.B.

ANSWER: Faux (French for “false”) gout — or pseudogout, as it is more commonly called — is like gout in many respects, but the differences between the two are significant.

In gout, uric acid crystals infiltrate joints and inflame them. In pseudogout, the crystals making their way into and around joints are calcium pyrophosphate dehydrate, CPPD. Just as uric acid crystals do, CPPD crystals inflame the joint and cause great pain. That’s not true of everyone who has these crystals. Some never experience a minute of pain.

The joints most affected in pseudogout are the knees and the wrists. Shoulders, ankles, elbows and hands also might be targets.

Who told you that you have this condition? A doctor requires X-ray examination of the affected joint before declaring that a person has pseudogout. Stronger evidence of the diagnosis is obtained by drawing fluid from the joint and examining it microscopically. The distinctive crystals of CPPD can be seen — proof positive.

Nonsteroidal anti-inflammatory drugs — Aleve, Motrin, Advil and many others — usually can control this illness and the pain it causes. If they don’t, an injection of cortisone into the joint will. For recurrent attacks, colchicine — the same drug used for gout — works for pseudogout, too.

The pamphlet on gout and pseudogout explains both illnesses and their treatments. To obtain a copy, write: Dr. Donohue — No. 302, Box 536475, Orlando, FL 32853-6475. Enclose a check or money order (no cash) for $4.75 U.S./$6 Can. with the recipient’s printed name and address. Please allow four weeks for delivery.

DEAR DR. DONOHUE: In my opinion, you don’t really exist. You’re just a ghost writer for Big Pharma and the corrupt AMA, nothing more than a drug pusher. I’d like to see this note in your column. — N.F.

ANSWER: Feel better now that you’ve gotten that off your chest?

Dr. Donohue regrets that he is unable to answer individual letters, but he will incorporate them in his column whenever possible. Readers may write him or request an order form of available health newsletters at P.O. Box 536475, Orlando, FL 32853-6475. Readers may also order health newsletters from www.rbmamall.com.