A new study revisits an area of the U.S. looking for fresh information on severe allergic reactions.

What health issue did the study examine?

Researchers looked at trends in anaphylaxis over ten years. They examined the causes of anaphylaxis, also known as a severe allergic reaction.

What do we know about this issue so far?

Many other studies illustrate the growing problem of severe allergic reactions. In this study, researchers revisited Olmstead County, Minnesota. They studied this area during two other time periods since 1983 to collect data on food allergies and severe allergic reactions.

What question did researchers try to answer?

How many people does anaphylaxis affect? What are the causes of severe allergic reactions? Do the causes differ by age group?

Who did the study include?

This study included men, women and children during the years 2001 to 2010.

What methods did the researchers use?

Researchers looked at past medical charts indicating severe allergic reactions. The charts belonged to county residents.

What did the researchers find?

Researchers discovered:

• A significant increase in anaphylaxis, with an average increase of 4.3% per year.
• A nearly 10% increase per year in the incidence rate for food-related anaphylaxis.
• Food triggered most of the reactions in children (up to age 9).
• Venom, such as from insects, triggered reactions in adults in their 20s and 30s.
• Medications sparked reactions in adults in their 30s.
• There were no anaphylaxis-related deaths.

Another key finding: Epinephrine administration increased over the years of the study. During the first two years of the study, 42% of patients reported receiving epinephrine. By the last two years, 57% did so.

Are there any limits to the study?

There are two main limits:

This county's population is less diverse than the U.S. overall. It is more educated, more white and wealthier. Findings may not apply to people of color, those with lower incomes or those with less education.

Also, researchers used medical records. So the study findings are dependent on the accuracy of those records.

What does this study mean?

This study showed a significant increase in people receiving epinephrine, the first treatment for severe allergic reactions.

It also showed that anaphylaxis and food-related anaphylaxis is rising.

Researchers suggested that:

• Doctors educate patients and prescribe epinephrine auto-injectors.
• It is helpful to increase access to epinephrine in public settings, such as restaurants, day cares, schools and workplaces.

Reference:
Lee, S., Hess, E.P., Lohse, C., Waqas. G., Chamberlain, A.M., Campbell, R.L. (2016). Trends, characteristics and incidence of anaphylaxis in 2001-2010: a population-based study. Journal of Allergy & Clinical Immunology.