Can Allergies Cause Fever?

An allergy season sign in the midst of trees.
  • Millions of Americans are affected by allergies each year. There is no cure for allergies, but they can be managed with the right treatment.
  • Fever is not a direct symptom of allergies; however, individuals with allergies are more prone to developing infections that may lead to fever.
  • Some allergies, such as rhinitis, are easy to self-diagnose, but food and medication allergies may require allergy testing.
  • People who know what their allergic triggers are can steer clear of them and avoid severe reactions.

According to the Asthma and Allergy Foundation of America (AAFA), over 50 million people are affected by allergies in the U.S. each year, with around 90,000 being hospitalized for severe allergic reactions.

However, the link between allergies and fever is unclear. A fever is usually a sign of other illnesses or underlying conditions and is generally accompanied by a combination of other symptoms.

In this article, we’ll cover allergies, their symptoms, causes and treatments, and their connection to fever.

What is an Allergy?

An allergy is a hypersensitivity to a substance most people can tolerate, such tree pollen, grass pollen, weed pollen, animal dander, dust mites, cockroaches or mold. When you have an allergy, your immune system produces antibodies when it comes into contact with certain substances (allergens).

Whenever you are exposed to an allergen, your body’s immune response may cause inflammation or irritation.

During an allergic reaction, your skin, eyes, nasal passages, and airways may be affected.

What are Some Common Allergy Symptoms?

Your symptoms may vary depending on the type of allergy and the severity of your reaction. If you have more than one allergy, it's possible to experience a combination of these symptoms.

Some common allergy symptoms include:

  • Rashes
  • A swollen or itchy tongue, lips, eyes, or face
  • Hives (red, raised patches on the skin)
  • Coughing or sneezing
  • Itchy or runny nose
  • Red, watery eyes
Key Point: What are the Different Types of Allergies?

Allergies may be seasonal or all year round. Most allergies require lifelong treatment. The main allergy types are:

  • Pollen allergy
  • Mold allergy
  • Pet allergy

Hay Fever vs. Fever

Despite its name, hay fever is not an actual fever. Also called allergic rhinitis, hay fever is characterized by the same symptoms associated with a common cold. These symptoms include, among others, the following:

  • Itchy or teary eyes
  • Nasal congestion
  • Runny nose
  • Sinus pressure
  • Loss of smell
  • Headaches

Fever is a rise in body temperature (anything above 99°F) that’s typically caused by an infection, but may be a symptom of nearly any medical condition.

Here are some illnesses and conditions that could cause fever:

  • Gastroenteritis (stomach bugs)
  • Ear infections
  • Strep throat
  • UTIs (urinary tract infections)
  • Bronchitis
  • Mononucleosis
  • Sinusitis
  • Colds and flu
Woman looking at thermometer while man sneezes into tissue.

How Can Allergies Cause Fever?

Allergies aren’t directly linked to fever, but they may make individuals more prone to infections that can cause fever.

Also, because allergic rhinitis (hay fever) has similar symptoms to colds and flu, it’s possible to confuse the two. If you assume you have hay fever but you actually have a cold or flu, you may incorrectly think that allergies are responsible for your fever.

But how do you know if you’re down with the flu, a cold, or seasonal allergies?

What is the Difference Between Colds, Flus, and Allergic Rhinitis?


  • Cold: Common symptoms include slight aches and pains, runny nose, sneezing, sore throat, cough, and tight chest. Rare symptoms include headaches, fever, weakness, and fatigue.
  • Flu: Common symptoms include high fever, headaches, severe body aches, prolonged fatigue and weakness, cough, and chest pain. Rare symptoms include runny nose, sneezing, and sore throat. Flu symptoms are more severe than cold symptoms.
  • Allergic Rhinitis: Common symptoms include sneezing, itchy and watery eyes, runny/stuffy nose, coughing, and postnasal drip. Rare symptoms include headache, body aches, fatigue/weakness, sore throat, and chest discomfort.


  • Cold: Rest, stay hydrated, and treat symptoms with pain medication and decongestants, such as nasal sprays or tablets.
  • Flu: Rest, stay hydrated, and treat symptoms with pain relief medication. You can also visit a doctor and have them prescribe antiviral drugs.
  • Allergic Rhinitis: Treatment options include antihistamines, nasal steroid sprays, allergy shots, sublingual tablets, and decongestants.


  • Cold: Keep your distance from people who are sick. Wash your hands. Don’t touch your eyes, nose, or mouth with unclean hands.
  • Flu: Keep your distance from people who are sick. Wash your hands frequently. Get your annual flu vaccine.
  • Allergic Rhinitis: Avoid allergic rhinitis triggers, such as animal dander and pollen.


  • Cold: Sinus infections, prolonged cough, asthma, and ear infections.
  • Flu: Pneumonia, ear and sinus infections, and a worsening of chronic conditions, like asthma and diabetes.
  • Allergic Rhinitis: Sinusitis, sleep disturbances, dental problems, ear infections, and asthma.
Key Point: How Do I Know if I Have a Fever?

The easiest way to tell whether you have a fever is to do a temperature check with a thermometer. If your temperature exceeds 99°F, then you’re likely running a fever.

Here are a few symptoms to watch for that can help you determine whether or not you have a fever:

  • Sweating
  • Weakness
  • Dehydration
  • Headache
  • Appetite loss
  • Swollen lymph nodes
  • Chills and/or shivering
  • A warm forehead

How Can I Prevent Allergies from Causing Fever?

Allergies can increase the risk of developing a bacterial or viral infection, so correctly managing your allergies will help keep fever and other symptoms at bay.

Therefore, the best way to prevent allergies from causing a fever is to know what you're allergic to and to stay away from these things.

Whether it's pollen, dust mites, animal dander, when you know what's triggering your allergic reaction, you can steer clear of it and avoid the complications.

Diagnose Your Allergies

If you get the sniffles around spring each year, pollen might be the trigger. In this case, allergic rhinitis is easy to self-diagnose; however, other allergens may be more tricky to identify and you’ll need an allergy test to get to the heart of the problem.

You can visit an allergist or a doctor’s office to have allergy testing done.

Depending on the state you’re in, you may be able to purchase an at-home allergy test that typically involves taking a blood sample and sending it to a lab to be analyzed.

Diagnosing allergies is the first step in developing an effective treatment plan for your condition, so consider one of these options:

Allergen test being conducted on someone's forearm.

Skin Prick Test

Sometimes called a scratch or puncture test, this is a relatively painless procedure that involves placing a sample of the substance (allergen) onto the skin and pricking it.

If, after 10 to 20 minutes, a wheal — a raised white bump ringed with red, itchy skin — appears, it’s likely you’re allergic to the substance.

Blood Test

Sometimes referred to as immunoassay tests, allergy blood tests involve taking a blood sample and testing it for antibodies, or more specifically for immunoglobulin E which has been linked to your body’s allergy response.

It can take a few days or up to two weeks to get the results of an allergy blood test.

Know Your Allergy Triggers

When you understand what’s causing your allergic reactions, you can avoid them.

If you have allergic rhinitis, avoiding known triggers — such as pollen, pet dander, mold, and house dust mites — can help you prevent severe allergic reactions.

Manage Your Allergies with Treatments

Prevention is better than cure, or treatment in this case, as there are no cures for allergies.

Accurately diagnosing your allergies and identifying your triggers by using a journal will greatly minimize the risk of an allergic reaction, but there are also a variety of treatment options available.

Depending on the type of allergies you have, you could use one or more of the following treatments:

  • Over-the-counter oral antihistamines
  • Prescription antihistamines
  • Nasal steroids
  • Allergy shots (immunotherapy)
  • Decongestants
  • Leukotriene modifiers (or leukotriene antagonists)
  • Alternative treatments, such as acupuncture
  • Nasal washes (saline solution in a neti pot)
Key Point: How Am I Worsening My Allergic Rhinitis Symptoms?

If you’re wondering why your hay fever has suddenly gone haywire, here are a few reasons:

  • You open your windows too often to let fresh air in: This may bring pollen into your home.
  • You hang your laundry outside to dry: Pollen can get trapped in the fibers of your clothes, and this makes your allergies worse when you wear the clothes.
  • You skip your evening shower: Bathing at night is essential for those with allergic rhinitis as it’s important to wash the pollen and dust from your skin and hair before bedtime.
  • You allow your pets to share your bed: As much as we love our cats and dogs, animal dander on the bedding will worsen allergies.
  • You wander outside on the wrong days: It’s best to stay indoors when it’s allergy season.
  • You don’t spring-clean often enough: Dust, dirt, mold, and debris worsen allergies.
  • You don’t use the right medication: Speak to your pharmacist or healthcare provider if you feel your antihistamines are not working effectively.
Woman blowing her nose into a tissue while petting her cat.

What Else Can Cause a Fever and Allergy-Like Symptoms?

A sinus infection, as well as flu and colds, can cause fever and allergy-like symptoms. If you’re unsure about what’s causing your fever, cough, runny nose, headaches, itchy eyes, or itchy nose, consult your doctor.

A doctor will provide an accurate diagnosis and a treatment plan that works for you.

How Should I Manage a Fever?

A fever is your immune system’s response to infection caused by bacteria or viruses. For the most part, it will have to run its course.

You can break a fever by doing a combination of the following:

  • Getting plenty of rest
  • Drinking fluids
  • Regulating your body temperature
  • Using over-the-counter medications

When Should I See a Doctor for a Fever?

If you have any concerns or questions about a fever (or any other medical condition for that matter), always reach out to a licensed healthcare provider.

It’s also important to contact or visit a doctor if:

  • You have a persistent fever (three days or longer).
  • You don’t respond to medication that’s meant to reduce your fever.
  • You experience confusion, light sensitivity, or neck stiffness.
  • Your temperature is 103°F or higher.
  • You have a severe headache or rash.

Where Can I Learn More About Allergies?

Allergy symptoms can be managed and don’t have to decrease your quality of life. Head over to LifeMD and make a telehealth appointment with a board-certified doctor or nurse practitioner. They can help diagnose your allergies, identify your triggers, and develop an effective treatment plan for you.

Dr. Payel Gupta

Dr. Gupta holds certifications from the American Board of Allergy and Immunology, American Board of Internal Medicine, and American Board of Pediatrics. With a deep interest in global health, she’s volunteered her clinical skills across many continents.

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This article is intended for informational purposes only and should not be considered medical advice. Consult a healthcare professional or call a doctor in the case of a medical emergency.

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