What can I do to relieve eye-related allergy symptoms?

DEAR DOCTOR K: I have allergies, and my eyes are affected the most. They're puffy, red and itchy. What can I do?

DEAR READER: Pollens, animal dander, dust mites and mold: The same allergens that cause sneezing and an itchy nose and throat can trigger allergy symptoms that affect your eyes, too. If your eyes are red and itchy, you may also have tearing, mucous discharge and swelling of your conjunctiva (the inside of your eyelid). This constellation of symptoms is known as allergic conjunctivitis. It can be uncomfortable, but it is not a threat to vision.

Are allergy shots effective?

DEAR DOCTOR K: I'm plagued by seasonal allergies. Should I consider immunotherapy?

DEAR READER: Many people know all too well the misery of allergies -- the sneezing, runny nose, postnasal drip, watery eyes and itchy throat. They try to fight back with allergy medications. But immunotherapy, also known as allergy shots, may be a better option.

Can exposing babies to common food allergens help prevent food allergies later on?

DEAR DOCTOR K: In a recent column you said that parents should give babies peanut products to help prevent peanut allergies. Does the new advice also apply to other common food allergens, like eggs or cow's milk?

DEAR READER: To answer your question I turned to my colleague Dr. Claire McCarthy, a primary care pediatrician at Boston Children's Hospital. For decades, the standard advice recommended by allergy specialists was to hold off on giving babies foods that commonly cause allergic reactions. Parents were advised not to give egg, dairy, seafood or wheat in their child's first year. And parents were told to wait until two or three years to give peanuts or other nut products. It turns out that was bad advice.

Can you give me specific advice to help control my allergies?

DEAR DOCTOR K: The weather's warming up. For me, that means one thing: allergies. Can you give me some specific advice to help keep my allergies under control?

DEAR READER: Inhaled pollen, from trees, grass and weeds, is responsible for hay fever. These allergens get into the air -- and into our noses, eyes and lungs --causing the symptoms that allergy sufferers dread.

Do products that claim to boost immunity actually work?

DEAR DOCTOR K: I guess everyone wants a strong immune system. But is there anything to the claims of products that advertise that they boost immunity?

DEAR READER: In a word, no. Our immune system does a remarkable job of protecting us from bacteria, viruses and other microbes. That's good, because they can cause disease, suffering, even death. It seems logical to want to give your immune system a boost.

Will giving my baby peanut products increase or decrease his risk for a peanut allergy?

DEAR DOCTOR K: My baby has an egg allergy. His doctor says this increases his risk of developing a peanut allergy. She recommends avoiding peanut products for now. But another doctor gave me the opposite advice. What should I do?

DEAR READER: If your child has a food allergy, you may well agonize over the safety of his every meal and snack. And no wonder. Food allergies can cause severe -- even deadly -- allergic reactions. Peanut allergies can cause bad rashes, severe difficulty breathing, a dangerous drop in blood pressure and other dangerous results. But a study recently published in The New England Journal of Medicine offers some hope for parents of infants who may be headed toward a peanut allergy. That hope is peanuts.

Does long term use of antihistamines cause dementia?

DEAR DOCTOR K: I've been taking over-the-counter antihistamines for years to control my allergies. Now I hear I may have to worry about dementia. How real is the concern?

DEAR READER: Antihistamine drugs have "anticholinergic" (an-tee-cole-in-ER-jik) effects. That means that they have some tendency to block the action of a natural substance called acetylcholine. This substance transmits messages in the nervous system. In the brain, it is involved in learning and memory; in the rest of the body, it stimulates muscles to contract.

What can I do to minimize the mold in my home?

DEAR DOCTOR K: We just found out that my son is extremely allergic to mold. What can I do to minimize the mold in my home?

DEAR READER: Even if your son is getting allergy shots or taking medications, the best way to control his allergy is to reduce his exposure to mold. Mold, along with mildew and yeasts, are the spores of fungi. Spores are very light and travel in the air. Because spores are capable of surviving in dry, unpleasant conditions, they can live a long time. But they especially thrive in damp, warm environments.

What is an asthma action plan?

DEAR DOCTOR K: My son was recently diagnosed with asthma. His doctor wants to put together an asthma "action plan." What is that?

DEAR READER: Asthma is a complicated and serious disease. It can behave differently from hour to hour and from day to day. A person with asthma needs a plan for what to do at each stage of the disease. I'll describe the elements of the plan in a minute, but first a little background on asthma itself.

What’s the difference between celiac disease and a gluten sensitivity?

DEAR DOCTOR K: Many people I know are going gluten-free. When I ask them why, I hear about gluten sensitivity and celiac disease. What do these terms mean?

DEAR READER: Gluten sensitivity and celiac disease are two separate conditions with one thing in common: gluten. Gluten is a protein found in anything made with grains such as wheat, rye or barley. Gluten is what makes breads chewy. Celiac disease is a disorder in which the body can't tolerate gluten.