Can Allergies Cause Fever?

When experiencing allergies, most people typically react with sneezing, watery eyes, nasal congestion and a runny nose. If you’ve heard the term hay fever—another name for allergic rhinitis—you might wonder, can allergies cause fever?

Initially, this might seem possible, given that allergies can lead to a range of symptoms. We’ll explore this topic to clarify if allergies and fever might be linked.

Can Allergies Cause Fever?

The short answer is that, despite the term “hay fever,” allergies do not cause a fever.

It’s important to note that the term "hay fever" can be misleading because it rarely involves a fever. (Hay fever, medically known as allergic rhinitis, refers to allergic reactions triggered by allergens such as pollen, dust mites, or pet dander. The body's immune response to these allergens causes its symptoms.)

Fever is ‌a sign that the body is fighting off a viral or bacterial infection.

With that said, allergy symptoms such as nasal inflammation, congestion and excess mucus production, can make you more vulnerable to bacterial or viral upper respiratory or sinus infection.

Stagnant mucus in the nose creates an environment where viruses and bacteria can thrive. Fever is a common symptom of a sinus infection, along with other symptoms like nasal congestion, postnasal drip, frontal headaches, and pain in the teeth [*].

Common Allergy Symptoms

Watch out for these common allergy symptoms:

• Sneezing
• Runny or stuffy nose
• Itchy or watery eyes
• Itchy throat or ears
• Coughing
• Skin reactions such as rashes or hives
• Wheezing
• Fatigue
• Headaches

These symptoms can depend on the person and the specific allergen affecting them. For example, someone with pollen allergies may experience sneezing, itchy eyes, and a runny nose during pollen season.

However, another person with the same allergen might experience more severe symptoms which affect their breathing. In these cases, seek immediate medical attention.

Can You Have Fever with Allergy-Like Symptoms?

You can experience a fever along with allergy-like symptoms, but it's important to understand that a fever is not a typical symptom of allergies themselves.

Certain conditions can cause both allergy-like symptoms and fever. These include:

Sinusitis

When allergens irritate the nasal passages, they can lead to inflammation and congestion, creating conditions favorable for bacterial growth. This can cause sinusitis, which is characterized by symptoms like facial pain or pressure, thick nasal discharge, and sometimes fever.

Respiratory infections

Viral infections such as the common cold or influenza (flu) can initially present with symptoms similar to allergies, such as sneezing, congestion, and runny nose. These infections may progress to include fever, along with body aches and fatigue.

Related: 3 Stages of a Common Cold

Allergic asthma

Individuals with allergic asthma may experience asthma attacks triggered by allergens like pollen or pet dander. During an asthma flare-up, symptoms can include coughing, wheezing, shortness of breath, and chest tightness. Severe exacerbations of asthma can lead to systemic inflammation and fever. It is imperative that any form of asthma be managed by a qualified medical professional.

Diagnosis

When diagnosing the cause of fever accompanied by allergy-like symptoms, your healthcare provider will thoroughly take your medical history and conduct a physical examination.

They'll evaluate your symptoms, such as whether they are seasonal or related to specific triggers. This helps distinguish between allergy symptoms and other conditions.

Diagnostic tests may include allergy testing to identify specific allergens that may cause your symptoms, or blood tests to check for a infection or other underlying conditions.

If you have a cough or expectoration, a sputum culture may be performed to identify bacterial or viral infections.

Treatment

Healthcare providers treat fever and allergy-like symptoms by addressing both the fever and the underlying allergic reactions. Depending on the diagnosis (e.g., allergies, sinusitis, viral infection), treatment options may include:

• Taking OTC (over-the-counter) medications to reduce fever or antihistamines to relieve allergy symptoms
• Using a comprehensive nasal spray such as Allermi to reduce nasal congestion, sinus pressure, and other symptoms
• Antibiotics if a bacterial infection is diagnosed
• Corticosteroids or allergy shots for severe allergies or asthma
• Getting plenty of rest helps the body recover
• Drinking fluids helps thin mucus and reduce congestion
• Adding moisture to the air to ease nasal passages
• Minimizing exposure to allergens that trigger symptoms

Lifestyle adjustments, besides the tips above, can help reduce allergens in your home in cases of hay fever or seasonal allergies [*].

These adjustments include keeping track of local pollen counts and limiting your exposure by staying indoors, showering after spending time outdoors, using air purifiers to trap indoor allergens, and following a weekly cleaning routine.

Related: What to Do When Allergy Medicine Doesn’t Work

When to See a Doctor for Fever and Allergy-Like Symptoms

If the fever lasts over three days or is consistently high (above 39.4°C or 103°F), seek medical help immediately. The same is true if your allergy-like symptoms have significantly worsened or changed over time, or symptoms are significantly interfering with daily activities or sleep.

Children and older adults with allergy symptoms should always consult a doctor before starting any treatment, as they may require specialized care.

The Bottom Line

While fever is not a symptom of allergies, sometimes, allergies can lead to a sinus infection, which may‌ result in a fever. Addressing fever and allergy-like symptoms requires understanding what has caused them.

For those with allergies, managing symptoms can prevent infections from developing. One effective option is a combination nasal spray like Allermi which combines active ingredients tailored to each patient's specific allergy symptoms.

Making necessary lifestyle adjustments are also key to maintaining your health and preventing future issues.

References:

1. Sinus Infection | Causes, Symptoms & Treatment | ACAAI Public Website. (2022, November 7). ACAAI Patient. https://acaai.org/allergies/allergic-conditions/sinus-infection/
2. Allergy-proof your home. (2022, December 22). Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/allergies/in-depth/allergy/art-20049365