By Mia Stephens  

As trees fill with color and bonfires scent the crisp air, autumn feels magical.  

But those piles of leaves and firewood can harbor mold spores – triggering seasonal allergies for millions each fall. Nearly 25% of adults in the United States experience seasonal allergies throughout the year. Although seasonal allergies typically peak during the months of April, May and June – they can also pack a punch September through December. 

VCU Health allergist Darshana Alle, M.D., breaks down what you need to know about fall allergens and remedies so you don’t fall behind managing seasonal allergy symptoms. 

What are the most common allergens in the fall?  

Ragweed pollen and mold spores are the most common allergens in the fall. The Ragweed plant is a weed that can grow wild anywhere but has a prevalence throughout the eastern and midwest regions of the U.S. Typically, Ragweed pollen begins to peak in late August through September and can last until the first frost. Its lifespan is usually limited to one season but can produce up to 1 billion grains of pollen, which is a lot for one season. 

Mold spores are also seen during this time of year, especially as the leaves begin to decompose. Early signs to tell if leaves are beginning to decompose (and might have mold) is if they start to turn black or white. 

How do fall allergies differ from spring and summer allergies? 

Pollen from trees is predominantly in the air during the spring, while grass pollen is more common in the summer. 

Even though there are different allergens for each season, the symptoms you may experience are all similar. 

Seasonal allergy symptoms include: 

• Sneezing 
• Itchy/watery eyes  
• Runny nose 
• Post-nasal drainage 

If you have an underlying dust mite allergy, it’s also important to note that you may experience worsening allergy symptoms during the fall because of spending more time indoors. 

How can I tell the difference between allergy symptoms and a cold or flu? 

Allergies and the cold or flu can cause similar symptoms like sneezing, runny nose, and congestion, but they differ in their causes and features. Allergies are due to an immune response to allergens (like pollen or dust mites) whereas the cold or flu are caused by various viruses. 

When it comes to allergies, itchy/water eyes can persist for several weeks or months. On the other hand, viral colds or the flu usually last 1 to 2 weeks and have other symptoms like sore throat, fatigue, body aches and a fever. 

A good indicator to tell the difference is by looking at mucus from your nose. If it’s clear and watery, you’re likely experiencing allergies. If it’s green, yellow or brown, you likely have a cold or the flu. Both allergies and viruses can lead to bacterial sinus infections. 

How does weather affect fall allergies? 

Warm, dry and windy days can exacerbate symptoms due to the pollen from the Ragweed plant being widely dispersed. Rain can temporarily reduce pollen levels but also cause an increase in mold growth, especially when heat and humidity are present. 

Can I build tolerance to seasonal allergens? 

Yes, you can build a tolerance to seasonal allergens.  Allergen immunotherapy, commonly called "allergy shots," are a great option for those who are looking for a long-term solution. This treatment involves regular shots for three to five years, with the injections gradually increasing concentrations of the allergens that cause your symptoms. Over time, these injections help your immune system build tolerance against the allergen that once caused a reaction. 

When it comes to taking Antihistamines, what are the different types available and when is it best to take them? 

Antihistamines are broadly categorized into first-generation and second-generation based on their properties and effects. 

First-generation antihistamines like diphenhydramine (Benadryl) are more likely to cause drowsiness and are recommended to be taken close to bedtime or prior to sleeping. 

Second and third-generation antihistamines like cetirizine or fexofenadine (Zyrtec and Allegra) are typically preferred for allergy relief due to fewer sedative effects. These can be taken at any time during the day. 

Other key practices we recommend allergy sufferers implement during the fall are keeping windows and doors closed to prevent allergens from coming into the home. Using high-efficiency air filters or investing in HEPA filters, showering nightly and monitoring the pollen forecast all can help with managing exposure to allergens and reducing symptoms. 

If your symptoms persist, consider making an appointment with an allergist to identify what may be triggering your symptoms. We can help you figure out the best course of action to relieve your symptoms and enjoy all that the fall season can offer. 

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