25 Worst Major Cities for Allergies in 2020

In this article we explore the 25 Worst Cities for Allergies. Click to skip ahead and jump to the 10 worst U.S. cities for allergies.

Scratchy throat, runny nose and cough? Well, before the fear of Covid-19 grips you, consider that allergy season is right around the corner! 

Living with allergies can be a never ending struggle. For a patient with allergies, it is a constant process of identifying the triggers that set off their symptoms. People might be allergic to different things. It might be a specific type of food, some contaminant in the air, or some other allergens like mold  plants, insects, animals, and drugs that one might come in contact with. This makes it important for your surroundings being free from the allergy causing triggers. Specific cities are therefore worse than others when it comes to living with allergies. 

For all you know, the places you are living in might be aggravating the allergies you have. It especially becomes more important to find out if specific places you are planning to travel to or are considering moving to, are safe and free from allergens that might trigger your allergy symptoms. 

While most allergies can be mild, symptoms like sneezing, throat scratching, cough, and annoying rashes are also common. However, symptoms can also be more severe or lead to health issues like low blood pressure (hypotension),breathing issues, hives, eczema and also asthma. Findings have indicated strong connections between allergies and asthma. Asthma can be triggered by pollen, dust or mold in certain patients. Asthma caused by allergies is also the most common type of asthma in the US. This is caused by the inflammation of the lungs as a result of allergy reaction, and ultimately causing asthmatic symptoms. 

Approximately 24 million Americans suffer from asthma, including 6 million children who are affected by it, according to American College of Allergy, Asthma and Immunology (ACAAI)

Quest Diagnostics, one of the leading diagnostic testing companies, has identified in its study that 53% of asthma patients had allergic tendencies. This has also prompted the  National Asthma Education and Prevention Program (NAEPP) to recommend patients to avoid exposure to common allergens in their surroundings. Considering this, the 30 most polluted cities in the US, can also be some of the cities to avoid. 

Food allergies are extremely common too. The  2014 National Health Interview Survey (NHIS), 5.4%  children suffering from food allergies. Eczema can also have a link to food allergies, especially caused by eggs, milk and peanut. Children may also develop hay fever due to progressive food allergies, and 8.4% of children in the US have been found to suffer from hay fever. 

Best Bumble Bios For Girls
Best Bumble Bios For Girls

Copyright: djoronimo / 123RF Stock Photo

Over the years, it has also been observed that the overall allergies trends have been rising in the US. Allergies connected to ragweed are the most common, and have grown over 15% in the last 4 years.  Southwest, Great Lakes, Mountain, and Plains States are the worst for ragweed allergies. 

Allergies occur when a patient’s immune system identifies an allergen as harmful and triggers the release of histamines to resist the contact with the specific allergens resulting in allergy symptoms. There are a few ways to discover allergy triggers, including skin prick test or food challenges. 

However, the best way or the “gold standard” in the journey of identifying allergens that are triggers for you, is the ImmunoCAP® specific immunoglobulin E (IgE) blood test (ImmunoCAP). The Quest Diagnostics Health Trends Report  by Quest Diagnostics (DGX), is based on a series of ImmunoCAP blood tests and hence, reveals some very comprehensive findings. Through these tests it has been identified that patients are susceptible or sensitized to at least 1 out of 11 common allergens. 

While allergies can be triggered by a number of things, there are certain allergens that most often affect specific patients or sensitization to certain allergens. “Sensitization” implies that a patient has an allergen-specific IgE. For finding out the worst major cities for Allergies, we can therefore take two routes. First is to identify levels of specific allergens like pollen or mold, present in the environment of each city. The widely circulated report by Asthma and Allergy Foundation of America (AAFA), “the 100 most challenging places to live with allergies,” is based on a methodology that tracks pollen levels, as well as allergy prescriptions in each city. 

The second approach is based on sensitization rates, by identifying the worst cities based on the highest sensitization to certain identified allergens. The “Allergen Sensitization Index” developed by the Quest Diagnostics examines combined sensitization levels across  5 allergen categories: food  (egg white, milk, peanut, soybean, and wheat), common ragweed, mold, house dust mites, cat epithelia (skin) and dog dander. 

The research tracks sensitization rates over 4 years in the 30 most populous metros. It was, however,  noted that allergen sensitization was a major cause of concern in all 30 cities. 

An increasing trend in the allergen-sensitization rate has also been noted in the study with a 19% increase in  the number of patients tested for these 11 allergens. Children also appear to be more susceptible to sensitization than adults. Senstiation to at least 1 allergen was 53%  among children while it  was at only 37% for adults. 

We have based our rankings of the worst major cities for allergies based on this comprehensive research. That being said, both studies have reiterated one fact –  “There is no place safe from allergies in America.”

Let’s take a look at our final rankings. 

25. San Antonio

Allergen Sensitization Index – 610

The South-Central Texas city, house house dust mites and ragweed pollen. Pollen count in the air is quite high and a cause of concern. Percentage of patients who are sensitized to ragweed pollen were 17% and those sensitized towards house mites were at 23%. 

Copyright: nicoletaionescu / 123RF Stock Photo

24. Sacramento

Allergen Sensitization Index – 614

Often called the City of Trees, it is quite given that Sacramento would have a reputation for having high pollen counts in its environment. Pollen levels can be as high as 7.3 to 9.6 out of 12. Sagebrush pollen is the most prevalent.  

cough, pneumonia, senior, cold, bronchopneumonia, blond, medical, patient, whooping, infection, bronchial, ill, sick, elderly, convulsive, cramps, woman, inflammation,
cough, pneumonia, senior, cold, bronchopneumonia, blond, medical, patient, whooping, infection, bronchial, ill, sick, elderly, convulsive, cramps, woman, inflammation,


23. Orlando

Allergen Sensitization Index – 616

Orlando is one of the top 5 cities for house dust mites allergies. Percentage of patients who are sensitized to house dust mites  were a whopping 29%. Mold spores are common in the Orlando year in the months of February to April, and August to October. The humid climate also contributes to allergen producing conditions. 

Mask COronavirus
Mask COronavirus

22. Las Vegas

Allergen Sensitization Index – 620 

Research shows that the 5 cities with highest sensitization rates to ragweed pollen all lie in the Southwest with Las Vegas appearing on that list too. The city is also one of the top worst cities for animal related allergens rate of sensitization going up to 22%. 


21. Seattle

Allergen Sensitization Index – 633

Seattle is one of the top cities that exhibit high sensitization rates for food allergies. Spring time also worsens pollen allergies in the city.

Evan Lorne/Shutterstock.com

20. Houston

Allergen Sensitization Index – 639

Houston has a high rate of sensitization for house dust mites at 28%, followed by food allergies at 19%. Weed pollen counts in the air are on the higher side too. 

19. Kansas City

Allergen Sensitization Index – 640

Kansas City has the third highest sensitization rate for Common ragweed. Rate of sensitization is at 24%. Allergens related to cats and dogs are also quite common. 

18. Denver 

Allergen Sensitization Index – 642

The city is the top most worst city for cat and dogs related allergens. Sensitization rates for animal allergens are 25%. Common ragweed being the next most common allergen in the area. Springtime is also the allergy season. 


17. San Francisco

Allergen Sensitization Index – 646

Summer is allergy season in the San Francisco area. Almost 20-30% of the population in the city experience seasonal allergies. Most allergens arise out of mold and grass, and mulberry, oak, pine and other trees are major causes of aggravating allergies. 

16. San Diego

Allergen Sensitization Index – 648

The cool weather and rains in San Diego provides perfect conditions for house molds spores to thrive. The city has the second highest sensitization rates for dust mites. Allergy season is therefore, throughout the year in the region. 


15. Saint Louis

Allergen Sensitization Index – 648

Overall high levels of  food allergies and pollen allergies makes Saint Louis one of the Worst major cities for allergies. Percentage of patients with sensitized towards food allergies were at 22%. 

14. Minneapolis-St. Paul

Allergen Sensitization Index -653

Ragweed pollen allergies and food allergies are the most common in this region. While ragweed sensitization rate was at 22%, sensitization rates for food and animal allergens stood at 20%. 


13. New York

Allergen Sensitization Index – 658

New York grabs the second spot when it comes to highest sensitization rates to animals. Warming temperatures in the city have also contributed to lengthening of the pollen allergy season in the city, and it is set to be at record high this year. 

Andrey Bayda/Shutterstock.com

12. Riverside-San Bernardino

Allergen Sensitization Index – 659

The city is one of the top 5 cities with highest sensitization rates for both mold and ragweed pollen. Quite explainable that it appears on the list of the worst cities for allergies.

Most Expensive Sunglasses In the World
Most Expensive Sunglasses In the World

11. Los Angeles

Allergen Sensitization Index – 660

Los Angeles is one of the worst cities for mold allergies. Over 17% of patients have shown sensitization towards mold. It fares quite high in sensitization rates for house dust mites as well, at 26%. The high pollution levels is likely a contributor to the high allergen levels in the city. 

Click to continue reading and see the 10 worst U.S. cities for allergies.

  Disclosure: 25 Worst Major Cities for Allergies is originally published at Insider Monkey.