Can Allergies Cause Your Lymph Nodes to Swell?
It's not uncommon for lymph nodes to become swollen due to allergies. Lymph nodes are small glands located throughout the body that play an important role in the immune system. When you have an allergic reaction, your immune system responds by releasing histamine and other chemicals that cause inflammation. This inflammation can result in swollen lymph nodes as your body works to fight off the allergic response.
Lymph nodes tend to swell in areas closest to where the allergen entered the body. For example, if you have seasonal allergies that affect your nasal passages and throat, the lymph nodes in your neck may become enlarged. Or if you have a food allergy that causes stomach discomfort, you may notice swelling in the lymph nodes in your abdomen. The swelling is a normal part of your body's efforts to get rid of the allergens.
Common Causes of Swollen Lymph Nodes from Allergies
There are a few key allergens that frequently lead to swollen lymph nodes:
- Seasonal allergies - Pollen from trees, grass, weeds and mold entering the nasal passages can trigger sinus congestion, runny nose, sneezing, and swollen lymph nodes in the neck/throat region.
- Food allergies - The most common food allergens like peanuts, tree nuts, shellfish, eggs, soy and wheat can cause swelling in lymph nodes near the stomach and intestines after ingestion.
- Pet dander - Exposure to proteins found in pet saliva, skin cells and urine can spark swollen lymph nodes in pet allergic individuals, especially in the neck, chest and groin areas.
- Venom allergies - Insect stings and bites from bees, wasps, hornets, yellow jackets and fire ants can trigger a reaction, leading to swollen lymph nodes near the sting site.
- Medication allergies - Allergic reactions to prescription or over-the-counter medications you take can cause lymph nodes to swell as your body fights off the allergens in the medication.
Symptoms Associated with Swollen Lymph Nodes from Allergies
Along with swollen lymph nodes, allergies can also produce other bothersome symptoms such as:
- Runny, stuffy nose
- Sneezing and coughing
- Itchy, watery eyes
- Hives, rashes or skin welts
- Tingling or swelling of lips, tongue, throat
- Wheezing, chest tightness, difficulty breathing
- Stomach pain, vomiting, diarrhea
- Dizziness, lightheadedness
The specific symptoms you experience will depend on the allergen and where in the body the reaction occurs. Even if you don't notice other allergy symptoms, pay attention to any swollen lymph nodes after exposure to known allergens.
Areas Where Lymph Nodes May Swell Due to Allergies
Lymph nodes are located throughout the body, so allergic reactions can cause swelling in many different areas:
- Neck - Front and back of the neck, under the jawbone or chin
- Underarms - Armpits
- Chest - Upper chest below the collarbone
- Abdomen - Groin, lower abdomen, lower back
- Elbows - Inside of the elbows
- Head - Behind the ears, back of the head
Pay attention to any lymph nodes that seem abnormally large or tender to touch. Even small allergic reactions can make lymph nodes swell temporarily.
When to See a Doctor for Swollen Lymph Nodes from Allergies
In most cases, swollen lymph nodes from allergic reactions go down within a few days to a week once the allergens clear your system. However, it's a good idea to see a doctor if you experience:
- Very large or painful lymph nodes
- Lymph nodes that remain swollen longer than 2-4 weeks
- Other concerning symptoms like high fever, night sweats, unexplained weight loss
- Swollen lymph nodes without any other allergy symptoms
These signs could point to an infection, immune disorder or other health condition that requires further evaluation and treatment. Even if swollen nodes are caused by allergies, your doctor can provide medications to help reduce the swelling and discomfort more quickly.
What Causes Lymph Nodes to Swell with Allergies?
To understand why allergies lead to swollen lymph nodes, it helps to first understand more about what lymph nodes do and how allergies affect the body.
The Role of Lymph Nodes
Lymph nodes are small, bean-shaped glands that filter lymph fluid as it circulates through the lymphatic system. Lymph fluid carries white blood cells that help capture and destroy viruses, bacteria and other invaders.
There are hundreds of lymph nodes distributed at strategic points throughout the body. Key jobs lymph nodes perform include:
- Filtering out toxins, waste products, dead cells and foreign invaders from lymph fluid
- Storing white blood cells and releasing them when infection strikes
- Allowing immune system cells to communicate with each other
When you have an infection, immune response or inflammation anywhere in the body, nearby lymph nodes swell as they fill with extra white blood cells to fight the condition. This serves to isolate and trap pathogens so they can't spread further.
What Happens in an Allergic Reaction
During an allergic reaction, the immune system identifies a harmless substance as dangerous. It releases antibodies like histamine to attack the perceived threat. This leads to inflammation and symptoms trying to expel the trigger.
As part of this response, immune cells in the lymph nodes activate and rapidly multiply. This causes the lymph nodes to enlarge as they fill up with additional infection-fighting cells.
So in summary, swollen lymph nodes are a reflection of your body's efforts to gear up its defenses against the allergens it mistakenly believes are harmful invaders.
Treatment and Relief for Swollen Lymph Nodes from Allergies
If swollen lymph nodes are caused by an allergic reaction, focus on treating the allergies first. This will calm your immune response and allow the lymph node swelling to subside. Key steps include:
1. Avoid the Allergen
Prevent additional exposure to whatever substance triggered the reaction. For seasonal allergies, this may mean staying indoors when pollen counts are high. For food allergies, eliminate that item from your diet. Ask your doctor for advice about avoiding known allergy triggers.
2. Take Antihistamines
Over-the-counter antihistamines like Claritin, Zyrtec, Allegra and Benadryl counteract the histamine released during your body's allergic response. This reduces symptoms like swelling, itching, runny nose and sneezing.
3. Use Nasal Steroid Spray
Corticosteroid nasal sprays such as Flonase and Rhinocort help decrease inflammation and congestion from allergies. Spraying directly into the nasal passages delivers anti-inflammatory medication right to the source of the reaction.
4. Try Leukotriene Inhibitors
Prescription leukotriene inhibitors like Singulair block the release of chemicals that cause allergy symptoms. This can help relieve swollen lymph nodes, along with other issues like hives, asthma and sinus swelling.
5. Get Allergy Shots
Allergy shots introduce small amounts of allergens to your body to build up tolerance over time. After a course of injections, your immune system becomes less reactive to allergy triggers. This causes less lymph node inflammation.
6. Use Cold Compresses
Applying cold compresses or an ice pack to swollen lymph nodes can help reduce pain and inflammation. Wrap the ice pack in a towel before applying to avoid damage to the skin.
7. Take Anti-Inflammatory Medication
Over-the-counter non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen (Advil, Motrin) and naproxen (Aleve) can relieve swelling and discomfort from inflamed lymph nodes.
8. Get Plenty of Rest
Allow your body time to recover by getting enough rest. Drink fluids to stay hydrated. Your immune system will calm down faster if you reduce activity while lymph nodes are swollen.
9. Massage Swollen Nodes Gently
Using very light pressure, you can massage swollen lymph nodes to encourage drainage of lymph fluid. This may help reduce size and tenderness.
If home treatments don't reduce the swelling within a couple weeks, see your doctor to explore other options. For severe allergic reactions, you may need steroids or other medications to get the lymph node inflammation under control.
When to Worry About Swollen Lymph Nodes
Swollen lymph nodes are usually nothing to worry about when they occur in response to an infection or allergic reaction. Your body is just doing its job and fighting off the perceived threat. However, there are some cases when swollen lymph nodes warrant medical evaluation:
They Last Longer Than 4 Weeks
It's common for lymph nodes to remain swollen for up to 2-4 weeks after your body encounters an allergen or infection. But if they don't start going down after a month, it's a sign your immune system is still overstimulated for some reason.
They Don't Decrease with Treatment
If antihistamines, allergen avoidance and other treatments aren't helping reduce the size of your swollen lymph nodes, that's a red flag. It likely means something other than allergies is causing the swelling.
No Identifiable Cause
Finding swollen lymph nodes without having any illness, infection or allergic reaction often merits evaluation to determine the underlying problem.
Additional Symptoms Develop
If you notice B symptoms like fever, drenching night sweats, unexplained weight loss or fatigue along with persistently swollen nodes, it could signal an immune disorder or more serious condition.
They Feel Very Hard or Fixed
Lymph nodes that feel solid, immobile or stuck in place rather than soft and oval-shaped need medical assessment. This may indicate a dangerous blockage in the lymph system.
They Appear Larger Than 2 Centimeters
While allergy-related swelling is typically mild, lymph nodes greater than 2cm signal high levels of inflammation and should be evaluated promptly.
See your doctor whenever swollen lymph nodes seem abnormal or severe. Catching any underlying health problems early on improves outcomes.
When Swollen Lymph Nodes Indicate Serious Conditions
Most of the time, transient lymph node swelling is harmless - just a reflection of active immune response. However, persistently enlarged lymph nodes or those without any obvious cause can sometimes be a sign of more serious medical conditions such as:
Cancer
Cancers in lymph nodes or other parts of the body can cause lymph nodes to swell as white blood cells cluster there. This is most concerning if nodes feel hard or fixed in place.
HIV/AIDS
One of the early signs of human immunodeficiency virus (HIV) infection is swollen lymph nodes throughout the body as the virus attacks immune cells.
Immune Disorders
Diseases like lupus, rheumatoid arthritis and Sjogren's syndrome cause immune dysfunction and chronic lymph node swelling.
Lymphoma
This cancer begins in infection-fighting cells of the immune system. Swollen lymph nodes are one of the characteristic symptoms of lymphoma.
Mono (Mononucleosis)
The Epstein-Barr virus causes mononucleosis leading to swollen lymph nodes, especially in the neck and armpits.
Tuberculosis
Swollen lymph nodes in the neck are common in tuberculosis, an infectious disease that most often affects the lungs.
So while allergies are a very common trigger for temporary lymph node inflammation, persistent, unexplained swelling should prompt medical evaluation for other possible sources. Working with your doctor can help determine if further testing or treatment is warranted.