If You Think You Can Get a Fever From Allergies, Think Again

If you find yourself sneezing and coughing during allergy season, it can be hard to know if your symptoms are from a cold or seasonal allergies. A fever can help you figure out what’s going on. That’s because allergies don’t cause a fever. If you’re having a fever along with other allergy symptoms, we’ll explain what it could be and what you can do.

Can allergies cause fever?

No, allergies don’t directly cause a fever. This may come as a surprise. After all, seasonal allergies are often called “hay fever.” But allergies can cause inflammation in your sinuses, which can lead to sinusitis (sinus infection). And this condition can cause fever. 

Your sinuses are like small caverns created within the bones of your skull. They’re located behind your forehead, beneath your nose, and under your cheeks and eyes. They’re usually filled with air. But allergies cause your sinuses to fill up with mucus (congestion). This creates an environment that can lead to infection and, as a result, a fever. 

So, a fever is a good way to tell the difference between allergies and an infection. This is because the rest of the symptoms can be quite similar. 

What are the more common allergy symptoms?

The most common seasonal allergy symptoms include: 

• Red, watery, and itchy eyes

• Puffy skin around the eyes

• Stuffy or runny nose

• Scratchy throat

• Sneezing

Many of these symptoms can also result from a viral infection, like the common cold or the flu. But there are some key differences between them.

Can viruses cause allergy symptoms?

Viruses like the cold or flu can cause symptoms similar to those you may have with allergies too. These include symptoms like:

• Stuffy or runny nose

• Scratchy throat

• Sneezing

But there are other ways to tell seasonal allergies apart from viruses and other health conditions that cause fever. Unlike allergies, viruses more often lead to:

• Fever: While a fever is a sign of an infection, it’s still possible to have an infection without a true fever. The flu is more likely to cause a fever than the common cold. 

• Cough: People with lung conditions like asthma may cough from allergies. But otherwise a cough is often a sign of the common cold, the flu, or pneumonia.

• Body aches: Muscle and joint pain are classic signs of an infection. This is more common with something like the flu. 

• Extreme tiredness: An infection tends to make you feel more tired than allergies. When you have a cold or the flu, you’ll likely feel more drained than normal.

This table shows which symptoms are possible with allergies versus a viral infection. 

Another way to tell allergies apart from the common cold or flu is by how long your symptoms last. Cold and flu symptoms tend to last around 7 to 10 days or less. Allergies can sometimes stick around for up to 2 to 3 weeks, depending on how long a person was exposed to an allergen. 

Quiz: How to tell if I have allergies or a cold​?

How to treat allergies and fever?

The approach to treating allergies depends on your symptoms and finding what works for you. The best medication for your allergies will relieve your symptoms and have minimal side effects. 

Let’s take a look at some of the most commonly used types of allergy medications.

When to seek care for allergy symptoms with fever

You don’t always need to seek care for a fever. Fever is one way your body works to prevent disease. Interestingly, there are different opinions on what temperature defines a fever. That’s partly because it’s normal for your body to change temperature throughout the day, ranging from 97.7°F to 99.5°F (36.5°C to 37.5°C). The average normal body temperature is 98.6°F (37°C). A temperature over 100.4°F (38°C) is usually considered a fever. 

That said, get medical attention for a fever as soon as possible if you experience any of these symptoms: 

• Fever higher than 103°F

• Fever that lasts longer than 3 days

• Difficulty breathing

• Chest pain

• Coughing up a lot of mucus, or mucus with blood in it 

• Severe headache

• Neck pain or stiffness 

• Pain or difficulty swallowing 

• Nausea and vomiting

• Trouble concentrating or confusion

• Passing out

• Purple spots on your skin

These symptoms can be signs of a more serious infection. A healthcare professional can help figure out what might be causing your fever and decide on the best next steps.

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Written by:

Cherilyn Davis, MD

Cherilyn Davis, MD, is a board-certified pediatrician in NYC. She's held local and national roles at the American Medical Women's Association, including board member of the physician division and physician chair of social media.

Edited by:

Alex Eastman, PhD, RN

Alex Eastman, PhD, RN, is a California-based registered nurse and staff medical editor at GoodRx, where he focuses on clinical updates and Latino health.

Reviewed by:

Farzon A. Nahvi, MD

Farzon Nahvi, MD, is an emergency medicine physician and author of “Code Gray: Death, Life, and Uncertainty in the ER.” He works at Concord Hospital in Concord, New Hampshire, and teaches at the Geisel School of Medicine at Dartmouth.

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