Nonallergic rhinitis often linked to hyper-responsive nerves

DEAR DOCTOR » I have been plagued with clear nasal drip for a couple of years. The constant dripping is most prevalent when I eat, lift something heavy or even just get up from a chair. I have tried various antihistamines and nasal sprays. What else is there?

DEAR READER » First, let’s look at the root of your problem: rhinitis, the inflammation of the mucous membranes within the nose. This common condition, which can cause nasal congestion, runny nose and post-nasal drip (the symptom you describe), affects 10 to 40 percent of the population in industrialized countries.

People may think that allergies are the cause of their symptoms, but chronic nonallergic rhinitis is the cause a third of the time. Notably, although people with allergic rhinitis often have a history of congestion before the age of 20, 70 percent of those with nonallergic rhinitis have no nasal symptoms until after age 20.

Many doctors, including myself, previously referred to the condition as autonomic rhinitis because of its connection to the autonomic nerves that go the nose. These nerves can become hyper-responsive, leading to nasal congestion and runny nose upon exposure to environmental stimuli, such as changes in temperature, especially cold temperatures. Autonomic nerves can also cause nasal symptoms when a person eats spicy foods, consumes hot foods or drinks, exercises, lifts heavy objects or simply changes position.

But the autonomic nerves may not be the only factor at play. An inflammatory response can also oc- cur with nonallergic rhinitis, caused by white blood cells that become active in response to chemical irritants like cigarette smoke, perfume, cologne, scented products and pollution. This inflammatory response can compound the autonomic response; it could also potentially be the root cause of your post-nasal drip.

The first aspect of treating nonallergic rhinitis is to rule out an allergy or specific environmental stimulus. The second step is to assess the use of nasal decongestants, such as Afrin or Sudafed. Chronic use of these medications by tablet or spray can cause a rebound of congestion when the medication is stopped. Heartburn, or acid reflux, also should be addressed because it can lead to rhinitis as well.

As for treatment, the oral antihistamines often used to treat allergies may not be helpful against nonallergic rhinitis, because allergies aren’t the cause. Nasal antihistamines have shown benefit in treating nonallergic rhinitis, however. So too have nasal steroids, which decrease the inflammation in the nose. The latter drugs need to be used for more than a week to show an effect, however, and some doctors are concerned about longer-term use.

It seems likely you have an autonomic component to your symptoms. If so, talk to your doctor about ipratropium nasal spray (Atrovent). It blocks nerve receptors in the nose that are part of the autonomic nervous system. Your doctor may recommend its use before eating, before heavy exercise and, if necessary, before exposure to cold and dry conditions. If that doesn’t work, a nasal steroid and possibly a nasal histamine are other options.