Why Allergies Can Cause Swollen Lymph Nodes and How to Find Relief

What Are Allergies and How Do They Cause Swollen Lymph Nodes?

Allergies occur when the immune system overreacts to a normally harmless substance called an allergen. Things like pollen, pet dander, foods, mold, dust mites, and insect stings can all provoke an allergic response.

When you come into contact with an allergen, your immune system produces antibodies like immunoglobulin E (IgE). These antibodies trigger the release of chemicals like histamine that cause allergy symptoms.

Swollen lymph nodes can develop as part of this allergic reaction. Lymph nodes are small glands spread throughout the body that filter lymph fluid and help fight infections. They often swell as a response to allergy-triggered inflammation.

Common Allergy Symptoms

Allergies affect different parts of the body and cause a wide range of symptoms including:

• Runny nose, congestion
• Itchy, watery eyes
• Sneezing, coughing
• Hives, itchy rashes
• Swollen lips, tongue, throat
• Wheezing, chest tightness
• Nausea, vomiting, diarrhea
• Dizziness, fainting

Why Allergies Can Cause Swollen Lymph Nodes

There are a few reasons allergic reactions often lead to swollen lymph nodes:

Fighting Allergens

When allergens enter the body, the immune system kicks into high gear producing antibodies and activating various white blood cells to attack. This amplified immune response causes widespread inflammation. Lymph nodes swell as they fill with these infection-fighting cells.

Draining Reaction Sites

The lymph system helps filter out allergens and transport immune cells. Lymph nodes near reaction sites like the nose and throat will drain these areas and swell up as they become congested with fluid, antibodies, and white blood cells.

Clearing Toxins

Some chemicals released during allergic reactions like histamine and leukotrienes are toxic at high levels. Lymph nodes help filter out these chemicals. This can make them inflamed and enlarged.

Common Sites of Swollen Nodes from Allergies

The location of swollen lymph nodes often corresponds to the site of allergen exposure. Common areas include:

Neck

Swollen lymph nodes in the neck indicate allergies affecting the head such as:

• Sinusitis
• Conjunctivitis
• Hay fever
• Reaction to inhaled allergens

Under the Jaw

Enlarged lymph nodes under the jaw can stem from allergies of the mouth like:

• Oral allergy syndrome
• Angioedema of the lips or tongue
• Salivary gland inflammation

Armpits

Swelling in the armpit lymph nodes often results from allergies affecting the arms or upper body such as:

• Hives
• Eczema
• Reaction to fragrances, cosmetics
• Latex allergy from gloves

Groin

Inguinal lymph nodes in the groin may enlarge due to allergic reactions of the lower body like:

• Poison ivy
• Jock itch
• Irritant or allergic contact dermatitis

Other Causes of Swollen Lymph Nodes

While allergies commonly cause swollen lymph nodes, other conditions can also lead to lymphadenopathy. These include:

• Infections - viral, bacterial, fungal
• Cancers like lymphoma, leukemia
• Autoimmune disorders
• Medications
• Trauma or injury

Swollen nodes from allergies are typically smaller, mobile, and tender. They decrease once the allergen is removed. Persistent, hard, or large lymphadenopathy may indicate a more serious underlying problem requiring medical evaluation.

Treating Swollen Lymph Nodes from Allergies

The main way to treat swollen lymph nodes caused by allergies is to control the allergic reaction and reduce inflammation. Strategies include:

Avoid Allergens

Preventing exposure to problematic allergens is key. Stay indoors during high pollen counts, use HEPA air filters, wash bedding regularly, avoid food triggers, and use allergen-blocking creams.

Over-the-Counter Antihistamines

Medications like Zyrtec, Allegra, and Claritin block histamine release and reduce allergic symptoms and lymph node swelling.

Nasal Steroids

Nasal steroid sprays like Flonase and Rhinocort help decrease lymph node swelling stemming from nasal allergies.

Cool Compresses

Applying cool, damp washcloths can help soothe tender, swollen lymph nodes and reduce inflammation.

Massage

Gently massaging swollen nodes helps stimulate drainage of fluid buildup and decreases swelling.

Stay Hydrated

Drinking adequate water keeps lymph fluid thin allowing better flow to drain swollen nodes.

Immunotherapy

Allergy shots or sublingual drops can help desensitize your immune system to specific allergens over time.

When to See a Doctor

Make an appointment with your doctor or allergist if:

• Swelling lasts more than 10-14 days
• Nodes feel very large, hard, or fixed in place
• You develop a persistent fever, night sweats, or weight loss
• Swelling is accompanied by severe pain or redness

Your doctor can help determine if swollen lymph nodes are due to allergies or another more serious condition requiring further evaluation and treatment.

Allergy Testing

Allergy testing like skin or blood tests can identify your unique allergen triggers. This allows you to target prevention and treatment more effectively.

EpiPen

If you have severe, life-threatening allergic reactions (anaphylaxis), your doctor may prescribe an EpiPen (epinephrine autoinjector) to immediately reverse symptoms.

Preventing Future Swelling

You can reduce flare-ups of swollen lymph nodes from allergies in the future by:

• Using HEPA air filters at home
• Washing bedding on high heat weekly
• Bathing pets weekly, keeping them out of bedrooms
• Taking off shoes when entering your home
• Seeing an allergist to get appropriate treatment

Controlling your allergies goes a long way in preventing recurrent episodes of swollen lymph nodes and other allergy symptoms.

The Bottom Line

It is very common for allergies to cause swollen lymph nodes. This results from the ramped up immune response and inflammation triggered by exposure to an allergen. The swelling is usually temporary and will improve along with other allergy symptoms once the trigger is removed. Taking antihistamines, applying cool compresses, and staying hydrated can all help reduce swollen lymph nodes from allergies. See your doctor if swelling is severe, persists longer than two weeks, or is accompanied by other concerning symptoms.

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a healthcare professional before starting any new treatment regimen.