For other types of allergies, see Asthma and Eczema.

About 7% of all Americans suffer from hay fever, an allergic condition that can cause runny nose, sneezing, and teary eyes. It is known officially as allergic rhinitis, allergic sinusitis, or allergic conjunctivitis, depending on whether symptoms manifest mainly in the nose, sinuses, or eyes, respectively. Hay fever usually peaks when particular plants are pollinating or when molds are flourishing. People who suffer from year-round hay fever (perennial rhinitis) may be allergic to persistent allergens in the environment coming from such sources as dust mites, mice, and cockroaches.

Here's how hay fever works. In response to the triggers noted above, an individual prone to allergies develops an exaggerated immune response. Substances known as IgEs flood the nasal passages, white blood cells called eosinophils arrive by the millions and billions, and inflammatory substances such as histamine, prostaglandins, and leukotrienes are released in massive amounts. The overall effect is the familiar one of swelling, dripping, itching, and aching.

The mechanism of allergic response is fairly well understood. Why allergic people react so excessively to innocent bits of pollen, however, remains a complete mystery.

Conventional treatment for hay fever primarily involves nonsedating antihistamines and nasal steroids and is usually quite effective.

The herb butterbur is best known as a promising new treatment for migraine headaches. However, butterbur may also be helpful for allergic rhinitis.

In a 2-week, double-blind, placebo-controlled study of 186 people with intermittent allergic rhinitis, use of butterbur at a dose of three standardized tablets daily, or one tablet daily, reduced allergy symptoms as compared to placebo.34 Significantly greater benefits were seen in the higher dose group. Such "dose dependency" is taken as a confirming sign that a treatment really works.

In another double-blind study, 330 people were given either butterbur extract (one tablet three times daily), the antihistamine fexofenadine (Allegra), or placebo.44 The results showed that butterbur and fexofenadine were equally effective, and both were more effective than placebo.

A previous 2-week, double-blind study of 125 individuals with hay fever (technically, seasonal allergic rhinitis) compared a standardized butterbur extract against the antihistamine drug cetirizine.18 According to ratings by both doctors and patients, the two treatments proved about equally effective. Unfortunately, this study did not use a placebo group.

Two much smaller studies produced inconsistent results.27,35

For more information, including dosage and safety issues, see the full Butterbur article.

An alternative to allergy shots known as sublingual immunotherapy(SLIT) involves using allergenic substances placed under the tongue. Numerous double-blind, placebo-controlled studies indicate that SLIT can improve all major symptoms of allergic rhinitis when the offending allergens are known.32,43,48,49,51,63,68,69However, in a 2008 comprehensive review of SLIT for grass pollen and house dust mite allergies, researchers raised questions regarding the quality and consistency of these and other studies.65

If SLIT is effective, it may require 2-3 years for significant benefit to develop.54One placebo-controlled study found that 3 years of treatment was more effective than 2 years.56In addition, to provide benefits for grass allergy season, SLIT must be started at least 8 weeks prior to the onset of the grass allergy season; even longer lead times lead to even better results.58 Putting all this evidence together, it appears that SLIT may work best if used year round, and year-after-year.

One study suggests that SLIT is not only effective for treating allergy, but may be useful in preventing the development of new allergies or mild persistent asthma in children with allergic rhinitis or intermittent asthma.70

While SLIT is fairly well accepted in conventional medicine, another form of “alternative” allergy shots remains firmly in the alternative medicine field: enzyme potentiated desensitisation(EPD). This method involves injections of allergens combined with certain enzymes. In one double-blind, placebo-controlled study, EPD failed to prove more helpful than placebo for seasonal allergic rhinitis.33