Could Allergies Cause Swollen Lymph Nodes?

Can Allergies Cause Swollen Lymph Nodes?

It's common for lymph nodes to become swollen or enlarged when fighting an infection. But lymph nodes can also swell up when experiencing an allergic reaction. Allergies cause the immune system to overreact, triggering inflammation that can spread to lymph nodes near the site of the reaction. While swollen lymph nodes from allergies are usually harmless, it's important to understand the cause and how to find relief.

What Are Lymph Nodes?

Lymph nodes are small, bean-shaped glands that are part of the lymphatic system. This important system helps fight infection and transport lymph fluid which contains white blood cells throughout the body. Lymph nodes act as filters, catching foreign invaders like bacteria and viruses. They contain immune cells that attack and destroy these threats before they can cause harm.

There are hundreds of lymph nodes distributed throughout the body. You can often feel swollen lymph nodes in the neck, under the jaw and chin, armpits, and groin which have clusters of nodes. But lymph nodes inside the chest, abdomen, and other areas deep in the body can also become inflamed when reacting to allergens.

How Do Allergies Cause Swollen Lymph Nodes?

Allergies happen when the immune system overreacts to a normally harmless substance like pollen, pet dander, dust mites, or certain foods. The body mistakes these allergens as dangerous invaders and releases chemicals like histamine to defend against them. This causes allergy symptoms we’re familiar with — itchy eyes, sneezing, runny nose, coughing, rashes.

Lymph nodes can swell as part of this immune response. When allergens enter the body, immune cells in the lymph nodes activate and multiply rapidly. This rush of activity causes the nodes to enlarge. The location of the swollen nodes depends on where you’re exposed to the allergen. For example, allergens breathed in through the nose can inflame lymph nodes in the neck.

Common Causes of Swollen Lymph Nodes from Allergies

There are many types of allergens that can cause swollen lymph nodes when your body reacts to them. Some of the most common causes include:

• Seasonal allergies - Pollen from trees, grasses, and weeds often triggers swollen lymph nodes in the neck and behind the ears as the body tries to filter out these airborne allergens.
• Dust mites - Microscopic dust mites in bedding, carpets, and upholstered furniture can inflame lymph nodes when inhaled or contacted.
• Pet dander - Dander, skin flakes, saliva and urine from furred pets like cats and dogs is a top cause of indoor allergies and swollen lymph nodes.
• Food allergies - Allergic reactions to peanuts, tree nuts, shellfish, milk, eggs, soy, wheat and other foods can cause localized lymph node swelling near the site of exposure.
• Bug bites and stings - The venom or saliva from bugs like mosquitos, bees, wasps, and spiders triggers swollen nodes as the body fights the allergen.
• Medications - Antibiotics and other drugs can cause allergic reactions and swollen lymph nodes in some people.
• Latex - Latex gloves, condoms, and other products contain latex proteins that can inflame lymph nodes when touched.

Signs of Swollen Lymph Nodes from Allergies

How can you tell if enlarged lymph nodes are caused by allergies versus a bacterial or viral infection? Signs that swollen nodes likely stem from allergies include:

• Appearing at the same time as other allergy symptoms like hives, rashes, congestion, or wheezing
• Only last a few days to a week during exposure to an allergen
• Being movable, soft, and tender to the touch
• Going away once the offending allergen is removed
• Returning seasonally or when re-exposed to the same allergen

Infected swollen lymph nodes may last longer, feel firm or hard, be immobile under the skin, and appear very red or purple. Consulting a doctor can help determine if swollen nodes warrant further testing for infection.

Treating Swollen Lymph Nodes from Allergies

To reduce swelling in enlarged lymph nodes caused by allergies, follow these self-care tips:

• Avoid your allergy triggers whenever possible to prevent a reaction.
• Take antihistamines like Claritin, Zyrtec, or Benadryl to control symptoms.
• Use nasal sprays like Flonase or Nasacort to decrease sinus swelling.
• Apply cool compresses to tender, swollen areas on the skin’s surface.
• Get plenty of rest and stay hydrated to support immune function.
• Wear loose, breathable clothing that doesn’t rub on affected lymph nodes.

If self-care strategies aren’t helping within a week or swelling is severe, see your doctor. They may prescribe steroid medications or antibiotics if signs of infection develop.

When to See a Doctor

You should make an appointment with your doctor if swollen lymph nodes from allergies:

• Don’t improve with allergy treatment
• Last longer than one to two weeks
• Feel very hard, immobile, or enlarged
• Are accompanied by high fever or chills
• Cause severe pain or interfere with swallowing/breathing
• Appear red, inflamed, or show streaking on the skin’s surface

These signs may require tests to rule out an infection, autoimmune disorder, or other medical condition requiring treatment. Biopsy and imaging tests like CT scans or ultrasounds can check lymph nodes for abnormalities.

The Bottom Line

It’s common and harmless for lymph nodes to swell from allergic reactions. Avoiding triggers, using allergy medications, and waiting it out is usually enough to reduce the swelling. But persistent or worsening lymph node problems should receive prompt medical care to determine the cause and appropriate treatment.

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.