Planning a vacation? Don't let allergies or asthma spoil your fun. "For a safe and healthy trip, be prepared before you leave home," says Clifford W. Bassett, M.D., a vice chair of the American Academy of Allergy, Asthma and Immunology. Here, his tips:

Packing

Got your gear? Pack all medications in original containers, in your carry-on bag. If you're asthmatic, don't forget your peak flow meter and nebulizer or "rescue" bronchodilator inhaler.

Flying? Get a letter from your doctor that explains your prescriptions, especially liquids. If you use an epinephrine auto-injector, then bring a paper prescription to help explain what it is.

Dust-mite sensitive? Take your own bedsheets.

By land
Need an allergy-friendly car? Close the windows and run the air conditioning in the "do not recirculate" mode. When renting a vehicle, ask for one that's smoke-free.

City driving? Travel during non-peak hours to avoid pollution. Also, plug in your portable nebulizer.

By air
Use supplemental oxygen? You may need it at normal cruising altitudes if you have severe chronic respiratory disease. Discuss your needs with the airline.
Food allergies? Airline food comes from a vendor, so flight staff may miss some information about ingredients. Ask in advance.
Pet allergies? Reserve a ticket on a pet-free plane. Always carry an antihistamine and meds.
Nasal allergies? Moisturize with a saline spray.

By sea
Allergies? Request an allergy-friendly cabin, which may have options such as wood or linoleum floors, blinds instead of heavy draperies, and leather furnishings in lieu of upholstered ones.
Severe allergies or asthma? Know the medical qualifications of cruise ship personnel and the availability of health care on board.
Eczema? Use a medicated ointment to minimize aggravation caused by water and sun.