What is allergen immunotherapy and should you try it?

If you're constantly sneezing and sniffling even though you take allergy medication to relieve symptoms, you may want to consider immunotherapy.

This treatment is aimed at desensitising you to your allergy triggers, providing long-term relief from allergies and reducing the risk for asthma.

Tablets under the tongue

Recent advances have made this option more appealing. Allergy shots used to be the only immunotherapy treatment approved by the US Food and Drug Administration, but in recent years, sublingual immunotherapies have proven effective. This approach involves putting tablets under your tongue for a minute or two and then swallowing them as they dissolve. Depending on the patient, the tablets may be taken three times a week or as often as daily.

Allergy testing is key to determine which of the available treatments might work for you. Some formulas are for people with seasonal allergies like ragweed, pollens and grasses, for instance, while others target year-round allergies such as dust mites found in the home. Some formulas are approved for different age groups.

Greatest benefit after 3 years

It's important to know that immunotherapy isn't an overnight fix. The drugs have a cumulative effect over time, both increasing your tolerance to the target allergen and easing your symptoms.

How much time? In a variety of studies, people saw the most benefit after three years of taking the tablets. Studies that looked at two years' worth of treatment found that this shortened course didn't yield good results.

Side effects are also possible, typically at the start of treatment, though they're often mild, such as stomach issues or an itchy mouth. Your doctor can help you manage them.

Finally, keep in mind that the effects of immunotherapy may not last indefinitely and you might need to repeat it, but typically you can expect a noticeable improvement in symptoms for at least two years after treatment.

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