OVERVIEW

What is lymphadenitis?

Lymphadenitis refers to the inflammatory reaction of lymph nodes caused by pathogenic bacteria (commonly Staphylococcus aureus and beta-hemolytic streptococcus) invading the lymphatic system through skin or mucosal damage or other infected lesions ^[1].

Based on the speed of onset and the duration of the disease, it can be classified into acute lymphadenitis and chronic lymphadenitis.

Clinical manifestations include localized lymph node swelling, pain, fever, and skin redness. The disease commonly occurs in areas rich in lymph nodes, such as the neck, armpits, groin, and submandibular regions ^[1].

The primary treatment for this condition involves the use of antibiotics. Patients with suppuration may also require surgical intervention, such as puncture drainage or incision and drainage ^[1].

Is lymphadenitis common?

This disease is common, but specific epidemiological data are currently unavailable ^[1].

SYMPTOMS

What are the symptoms of acute lymphadenitis?

1. Redness, swelling, heat, and pain: Firm and tender lymph nodes can be felt, with redness and swelling in the surrounding skin and elevated skin temperature (compared to normal skin temperature)^[1].
2. Abscess formation: If the infection worsens, pus may form, and the lump may feel fluctuant (like touching a water-filled balloon), with more pronounced pain^[1].

What are the symptoms of chronic lymphadenitis?

1. General symptoms: Painless, enlarged lymph nodes can be felt in superficial areas such as the neck, behind the ears, under the jaw, armpits, or groin. They are hard, smooth, and mobile, sometimes accompanied by tenderness or discomfort.
2. Acute phase symptoms: When inflammation spreads to surrounding tissues, the swollen lymph nodes become immobile upon palpation, with increased pain. This may progress to local cellulitis, with redness and warmth in the overlying skin, and sometimes fever accompanied by symptoms such as chills, loss of appetite, difficulty swallowing, rapid breathing, neck stiffness, or abdominal pain.

What complications can lymphadenitis cause?

1. Bacteremia: A small number of pathogens enter the bloodstream but do not multiply or multiply minimally, causing mild inflammatory reactions such as chills, fatigue, and fever.
2. Septicemia: Caused by the spread of pus through lymphatic or blood vessels, leading to systemic infection. Main symptoms include chills, fever (>38°C), shortness of breath, and confusion.

CAUSES

What are the causes of lymphadenitis?

When bacteria (such as *Staphylococcus aureus*, *Streptococcus pyogenes*, etc.) or viruses (such as influenza virus, etc.) invade the body, they enter the lymphatic system and repeatedly or persistently stimulate local lymph nodes, leading to significant lymphocyte proliferation and causing lymphadenitis ^[1].

What are the predisposing factors for lymphadenitis?

1. Immune factors: When immunity is weakened, the defensive function of the lymphatic barrier is insufficient to resist bacterial or viral invasion, which may trigger the disease ^[1].
2. Local skin damage: Skin breaks or ulcers in the head, face, or neck make it easier for pathogens to invade the lymphatic system through damaged skin or mucous membranes, thereby inducing the disease.
3. Disease factors: Conditions such as upper respiratory infections, skin or mucosal infections, or oral infections can indirectly infect lymph nodes through inflammatory mediators produced by pathogens, leading to lymphadenitis.
4. Medication factors: Long-term use of hormones (e.g., prednisone, cortisone) or immunosuppressants (e.g., tacrolimus, cyclophosphamide) may reduce immunity and contribute to chronic lymphadenitis.

Which groups are more susceptible to lymphadenitis?

Lymphadenitis is often caused by pathogenic infections, so the following groups are at higher risk:

1. People with weakened immunity: Such as those who frequently stay up late, are overworked, or under high stress.
2. Individuals with other infectious diseases: Such as upper respiratory infections, skin or mucosal infections, or oral infections.
3. Those with local skin breaks: Such as ulcers or wounds on the head, face, or neck.
4. People who misuse medications: Such as long-term use of hormones (e.g., prednisone, cortisone) or immunosuppressants (e.g., tacrolimus, cyclophosphamide).

DIAGNOSIS

Which department should I see for lymphadenitis?

General Surgery, Otolaryngology-Head and Neck Surgery.

What tests are needed for lymphadenitis?

1. Physical examination: The doctor will palpate superficial lymph nodes to assess their size, texture, mobility, tenderness, and local skin temperature.
2. Complete blood count (CBC): Used to determine if there is an infection. If the white blood cell count is normal or slightly elevated, and inflammatory markers like C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) are elevated, it confirms an infection and aids in diagnosis ^[1].
3. Pathogenic examination: Bacterial culture or smear tests are performed to identify pathogenic infections. Detection of pathogens confirms the diagnosis and helps guide treatment.
4. Imaging tests: Including chest X-rays, ultrasound, and CT scans, which reveal the morphology, size, and affected areas of lymph nodes, aiding in accurate diagnosis and disease progression assessment [2].
5. Histopathological examination: A lymph node biopsy can accurately determine the nature of the lymph node and confirm the diagnosis ^[3].

Which diseases are easily confused with lymphadenitis?

1. Lymphoma: Both conditions may present with lymph node enlargement and fever. However, lymphoma-associated lymph nodes are typically painless, lack a primary infection site, and may be accompanied by night sweats, weight loss, and skin itching. In contrast, lymphadenitis involves tender lymph nodes with an identifiable infection source. A lymph node biopsy can differentiate the two.
2. Lymph node metastasis from other malignancies: Such as thyroid cancer, breast cancer, or gastric cancer. If enlarged lymph nodes are found, seek medical attention promptly and provide a detailed medical history. The doctor may order imaging or histopathological tests to rule out malignancy.

TREATMENT

How to treat lymphadenitis?

This condition is generally managed with medication to control infection. Surgical treatment may be performed if the lymph node swelling cannot be resolved or is significantly enlarged.

1. Medication:
   1. Antibiotics ^[1]: Commonly used drugs include penicillin and cephalosporin antibiotics, which can inhibit bacterial growth, control inflammation, and relieve symptoms. Adverse reactions include allergic reactions (such as urticaria) and gastrointestinal reactions (nausea, vomiting, diarrhea). Contraindicated in individuals allergic to the drug components.
   2. Antipyretic analgesics: Commonly used drugs include ibuprofen, which helps control pain and fever. Adverse reactions include abdominal pain, dizziness, and tinnitus. Contraindicated in individuals allergic to the drug, pregnant or breastfeeding women, and those with severe liver or kidney dysfunction.
2. Surgical treatment: When acute lymphadenitis forms an abscess, an abscess incision and drainage procedure is required to quickly remove pus and reduce inflammation [1]. However, as an invasive procedure, it may increase the risk of secondary infection.

Can lymphadenitis be cured?

Yes, it can be cured. With timely and effective treatment, the patient's lymph nodes return to normal, and symptoms such as skin redness and fever disappear ^[1].

However, a few cases of acute lymphadenitis may persist and develop into chronic lymphadenitis. Therefore, once diagnosed, the primary infection should be actively treated to prevent recurrence of lymphadenitis.

DIET & LIFESTYLE

What should patients with lymphadenitis pay attention to in their diet?

1. Limit the intake of spicy and irritating foods (such as chili peppers, Sichuan peppercorns, leeks, strong tea, coffee, etc.), as spicy foods can aggravate inflammation and lead to recurrent lymphadenitis ^[4].
2. Consume more fresh fruits and vegetables, such as bananas, apples, corn, and carrots, as they are rich in vitamins and minerals, which help boost immunity and promote recovery ^[4].

What should patients with lymphadenitis pay attention to in daily life?

1. Quit smoking and drinking, engage in moderate exercise (such as jogging or walking for half an hour daily), and balance work and rest to enhance the body's ability to resist bacteria and viruses. Ensure sufficient rest and sleep (7–8 hours per day) to maintain good immune defense.
2. Take medications strictly as prescribed by the doctor. Do not change the dosage or frequency without permission, and follow the doctor's instructions regarding medication precautions.
3. Relax and practice self-psychological adjustment. Listening to soothing music and maintaining a cheerful mood can be beneficial.

Does lymphadenitis require follow-up examinations? How is lymphadenitis re-examined?

Yes, follow-up examinations are necessary. Follow the doctor's instructions for scheduled re-examinations: one week after surgery or one month after medication. The main method is ultrasound to assess lymph node size and evaluate recovery progress.

PREVENTION

Can Lymphadenitis Be Prevented? How to Prevent Lymphadenitis?

1. Reduce the use of hormones (such as prednisone, cortisone, etc.) and immunosuppressants (such as tacrolimus, cyclophosphamide, etc.). If they must be used, take them as prescribed by a doctor.
2. Those with skin wounds should clean the injury and protect the wound to avoid infection by pathogens.
3. Maintain a regular daily routine and balance work with rest to improve immunity and enhance resistance to diseases.
4. People with infectious diseases (such as respiratory infections, skin and mucosal infections, etc.) should actively treat the primary condition to prevent the infection from spreading to the lymph nodes.