Posted on: Saturday, March 19, 2005
PRESCRIPTIONS
Runny nose can be symptom of lots of things
By Landis Lum
Q. I've had a runny nose the past week. How do I know if it's an allergy or a cold caused by a virus?
A. Do you also have itchy watery eyes or an itchy nose? If so, especially if you've had such allergic rhinitis episodes in the past, it's probably hay fever due to an allergy. But if you have one or more signs of infection, like sore throat, diarrhea, fever, swollen neck glands, or muscle aches, then it's probably a cold. A cough usually means cold, but can also be due to asthma from allergy.
If you can't tell if it's allergy or infection, then it might be a foreign body or some other anatomical abnormality in the nose. If an exam by the doctor shows none of these, then skin or blood tests for allergies may be needed.
Allergies are likely if pollens, molds, or dust seem to set things off, or if you've had hives, asthma or eczema in the past. If tests are still negative for allergies, then you have nonallergic rhinitis, which is present in as many as half of all people with nasal symptoms and affects as many as 17 million Americans. And about 22 million people suffer with a combination of nonallergic and allergic diseases (mixed rhinitis).
So if it's a cold, antibiotics won't help since they don't work against viruses, though decongestants like norephedrine, oxymetazoline, or pseudoephedrine will reduce nasal congestion.
One case control study found weak evidence that phenylpropanolamine may cause strokes. Echinacea is of questionable benefit. And the superlative Cochrane Database of Systematic Reviews found that high doses of vitamin C even taken at the start of a cold don't work. They also found inconclusive evidence for the effectiveness of zinc lozenges. Two randomized studies showed zinc intranasal gel worked, though a third found it didn't.
Antihistamines may cause sleepiness and don't help colds much. But if your cold is not getting better by the 10th day, or you develop facial pain or pressure or a toothache, then you may have sinusitis and may need antibiotics.
For hay fever, avoid whatever's causing it. Use nonsedating antihistamines like fexofenadine, loratadine or desloratadine, or intra-nasal steroids for persistent symptoms. Allergy shots work but sometimes cause dangerous reactions.
For nonallergic rhinitis, intra-nasal steroids or Azelastine nasal spray work the best. Salt-water sprays or irrigation alone may reduce postnasal drip, sneezing, and congestion. But make sure you don't have another cause for rhinitis, like overuse of nasal decongestant sprays, occupational exposure to odors, fragrances, or chemicals; hypothyroidism, chronic sinusitis, nasal septal deviation or polyps, drugs like Hytrin, Labetalol, birth control pills or aspirin, etc. But often, only your nose knows ...
Dr. Landis Lum is a family-practice physician for Kaiser Permanente and an associate clinical professor at the University of Hawai'i John A. Burns School of Medicine. Send your questions to Prescriptions, Island Life, The Advertiser, P.O. Box 3110, Honolulu, HI 96802; fax 535-8170; or write islandlife@honoluluadvertiser.com. This column is not intended to provide medical advice.
