Is eczema just dry skin?

DEAR DOCTOR K: I took my son to the doctor because he was constantly scratching his legs. The doctor says it's eczema. Is that just a fancy word for dry skin?

DEAR READER: Eczema (also called atopic dermatitis) is more than dry skin. It is an allergic skin condition that can make a child miserable. Treatment can usually help control the condition and ease its symptoms. Eczema can look different in different children. It can be bumpy or scaly, with small or big patches. The amount of redness also varies. Dry, scaling skin usually occurs along with it.

What are alternative therapies for rheumatoid arthritis pain?

DEAR DOCTOR K: I have rheumatoid arthritis. Medications have helped, but only up to a point. Can you discuss alternative therapies that might help to further relieve my discomfort?

DEAR READER: Rheumatoid arthritis (RA) is a long-term disease in which the body's immune system attacks healthy tissue lining the joints. This causes swelling, pain, redness and stiffness in joints throughout the body. Drug treatments slow the effects of the disease, but alternative approaches can also help to reduce inflammation and relieve pain.

Should I be concerned about my heart while shoveling snow?

DEAR DOCTOR K: Every winter my wife worries that I am going to have a heart attack while shoveling snow. Does she have cause for concern?

DEAR READER: She does. Each winter, more than 1,200 heart-related deaths occur during or after snowstorms. Shoveling snow is risky for many reasons: Shoveling is similar to weight lifting. Resistance exercise raises both heart rate and blood pressure, stressing the heart. Cold weather affects the heart. To conserve body heat in the cold, blood vessels narrow. This raises blood pressure and puts stress on the heart.

Is yogurt a healthy choice for breakfast or as a snack?

DEAR DOCTOR K: Is yogurt a healthy choice for breakfast or as a snack?

DEAR READER: You've heard me talk frequently about "good" and "bad" fats, and "good" and "bad" carbs. So it won't be surprising when I say there are "good" yogurts and "bad" yogurts. Here's what I mean. Yogurt -- plain, low-fat yogurt -- is a healthy food. But many yogurt products contain ingredients you could do without, like added sweeteners. So let's talk about what to look for in a healthy yogurt.

Should my child get the measles vaccine?

DEAR DOCTOR K: Should I vaccinate my daughter against measles?

DEAR READER: I was born before there was a measles vaccine, and I got the measles. Like most kids, I had a rash and a fever. (See the feature image for a photo of the measles rash.) And, like most kids, within one or two weeks I was back to normal. I remember, though, that my mother seemed more worried about me than she had been when I caught other viral illnesses. She knew three things I didn't. First, measles could sometimes cause very serious illness (blindness, brain and lung infections), even death.

Are poop pills really used to treat diarrhea?

DEAR DOCTOR K: I overheard a colleague talking about "poop pills" used to treat diarrhea. That can't be right. Can it?

DEAR READER: Yes, "poop" means what you think it means. Same thing as "doo-doo." It's gross, but it's true. So-called "poop pills" are being used to treat diarrhea caused by bacteria called Clostridium difficile, or "C. diff." Let me explain. Our intestines are filled with many different kinds of bacteria. Most live happily there; they don't invade or attack the intestine that is their home.

How can I prevent my child catching hand, foot and mouth disease?

DEAR DOCTOR K: Two children in my daughter's day care have hand, foot and mouth disease. How can I make sure my daughter doesn't catch it?

DEAR READER: Hand, foot and mouth disease is a common illness caused by the Coxsackie virus. The disease most often affects infants and children younger than 5 years. The illness usually starts with a fever. The child acts listless. A day or two later, sores appear around or inside the mouth and throat. If the child is old enough to talk, he or she is likely to complain of mouth or throat pain. Because of the sores in the mouth and throat, the child also may refuse to eat because it hurts.

Is the food pyramid still accurate?

DEAR DOCTOR K: Is a healthy diet still based on the food guide pyramid? Is there a better alternative?

DEAR READER: Twenty years ago, the USDA created its food guide pyramid. This symbol featured fats and oils at the tip and breads and grains at its base, with fruits, vegetables, meat and dairy in between. The pyramid was meant to convey, in a simple illustration, everything needed to build a healthful diet. But the original pyramid, as well as the updated 2005 version, was easy to misinterpret. For example, some people thought the top foods were most important, rather than the other way around.

Why is it harder for our eyes to focus on close objects as we get older?

DEAR DOCTOR K: Why does it become harder for our eyes to focus on close objects as we get older?

DEAR READER: The eye is like a camera: It has a lens that continuously focuses to sharpen the picture. As light rays enter the eye, the flexible lens alters its shape, allowing the eye to focus on objects at varying distances. The lens focuses light rays on the retina, the light-sensitive layer at the rear of the eye. As we age, the lens of the eye becomes increasingly inflexible. As a result, light rays focus behind the retina, rather than on it. This is called presbyopia. (Below, I've put an illustration of how the lens focuses light rays in a normal eye and in a presbyopic eye.)

What is a stress fracture?

DEAR DOCTOR K: What is a stress fracture?

DEAR READER: A patient of mine once asked me the same question, but with a twist: "In the emergency room they said I had a stress fracture. That's ridiculous, right? I mean, they're blaming stress for causing nearly every symptom these days. But how can stress cause a bone to break?" It's not emotional or mental "stress" that the word refers to in a stress fracture. It is stress -- unusual physical pressure -- placed on a bone that causes it to break. And the break typically does not separate the two ends of the bone. The X-ray, CT scan or MRI scan often shows no abnormality in the shape of the bone. Instead, there is a hairline crack inside the bone.