Pollen consists of tiny grains essential for plant reproduction. For many individuals, however, exposure to pollen triggers an immune system overreaction, commonly known as hay fever. A common question is whether these allergic reactions can also lead to a fever.
Understanding Pollen Allergies
Pollen allergies develop when the immune system mistakenly identifies harmless pollen as a threat, initiating an allergic reaction. The immune system produces immunoglobulin E (IgE) antibodies in response to the allergen. These IgE antibodies attach to mast cells, abundant in tissues like the nasal lining.
Upon subsequent pollen exposure, the allergen binds to IgE antibodies on mast cells. This triggers mast cells to release chemical mediators like histamine into surrounding tissues. Histamine and other compounds cause localized inflammatory responses: dilated blood vessels, increased mucus production, and stimulated nerve endings. This process causes pollen allergy symptoms.
Typical Allergy Symptoms
Pollen allergies primarily affect the upper respiratory tract and eyes. Individuals often experience frequent sneezing, a runny nose with clear discharge, and nasal congestion, all stemming from inflammation in the nasal passages.
Itchy, red, and watery eyes are typical as the immune system reacts to pollen. Some individuals also report an itchy throat, mouth, or ears, along with postnasal drip. Fatigue can accompany these symptoms, making individuals feel unwell.
Fever and Allergic Reactions
Fever is not a typical or direct symptom of pollen allergies. Allergic reactions are inflammatory responses to a threat, not infections causing systemic fever. The immune response in allergies does not involve pyrogens, substances that raise body temperature. Therefore, allergies alone do not directly increase core body temperature.
However, fever might coincide with allergy symptoms due to secondary complications or co-occurring illnesses. Prolonged inflammation and congestion from allergies can create an environment conducive to secondary bacterial or viral infections. For instance, persistent nasal congestion can block sinus drainage, leading to sinusitis, which can cause fever. Ear infections can also develop as a complication of allergies and may present with fever.
Individuals experiencing allergy symptoms might also contract common viral illnesses, such as a cold, flu, or COVID-19. These concurrent infections cause fever, body aches, and general malaise, distinct from the allergic reaction itself. The presence of fever indicates a co-existing infection, not a direct result of the allergy. Some people might misinterpret feeling “run down” or fatigued from severe allergy symptoms as a low-grade fever, even when their temperature is normal.
When to Seek Medical Attention
Seek medical attention if allergy-like symptoms are accompanied by certain indicators. A persistent or high fever, especially one exceeding 100.4°F (38°C), warrants consultation with a healthcare professional. This suggests a secondary infection or another underlying illness requiring diagnosis and treatment. Difficulty breathing, wheezing, chest pain, or shortness of breath are serious signs requiring immediate medical evaluation.
Additionally, if symptoms worsen despite over-the-counter allergy medications, or if they are unusually severe, seek medical advice. Unexplained or severe symptoms, such as significant swelling of the face, lips, or tongue, also necessitate prompt medical attention. Consulting a healthcare provider can help determine the precise cause of symptoms and ensure appropriate management, especially when uncertainty exists about whether symptoms stem from allergies or another condition.