Swollen lymph nodes can be a symptom of mpox, formerly known as monkeypox. A person with mpox may also have a rash and other flu-like symptoms. However, many other infections also cause swollen lymph nodes.

Evidence suggests that the most common site of swollen lymph nodes in mpox is the groin region, but other possible sites include the neck or under the jaw.

According to the Centers for Disease Control and Prevention (CDC), the lymph nodes may swell before or after the rash appears, but sometimes they may not swell at all.

This article discusses the relationship between swollen lymph nodes and mpox, including the location, other symptoms, and how long they take to develop. It also explains what to do if a person suspects they have mpox.

People waiting in line for monkeypox vaccines outside a hospital.Share on Pinterest
Irfan Khan/Los Angeles Times via Getty Images

Yes, swollen lymph nodes are a common mpox symptom.

The lymph nodes swell in most people before the mpox rash appears. When a person experiences swollen lymph nodes and other flu-like symptoms, the rash typically develops 1–4 days later.

However, mpox symptoms do not always manifest in this way. Sometimes the swollen lymph nodes and other symptoms appear after the rash, or the lymph nodes may not swell at all.

Swollen lymph nodes are also a common side effect of the mpox vaccine.

Lymph nodes are small glands. When a person has an infection, they can swell. The nodes may feel noticeably large, firm, or tender. In some cases, it may be possible to see the swollen lymph nodes beneath the skin.

A 2022 study suggests that the groin is the most common site of swollen lymph nodes from mpox, but they may also swell in the neck and under the jaw. Occasionally, this symptom can occur under the arms or behind the ear.

The main symptom of mpox is a rash that initially looks similar to pimples or blisters. The rash can be itchy and painful. It can appear on the:

  • chest
  • feet
  • hands
  • mouth
  • face
  • near the genitals, including the:
    • anus
    • vulva
    • labia
    • penis
    • testicles

Other symptoms of mpox may resemble a cold or flu and can include:

A virus causes mpox, and viruses have an incubation period. This is the period of time it takes between contracting a virus and symptoms developing.

For mpox, the incubation period typically ranges from 3–17 days, with symptoms usually starting within 3 weeks. This can mean people have mpox for a while before they develop symptoms.

A rash is the most distinctive symptom of mpox. Because it can occur with or without swollen lymph nodes and flu-like symptoms, a rash may be a more reliable sign that a person has mpox than swollen lymph nodes alone.

However, many other infectious illnesses can also cause a rash and swollen lymph nodes. The only way to be sure is to speak with a doctor.

Mpox transmits through close or intimate contact with a person who has the infection, such as:

  • hugging
  • massage
  • kissing
  • vaginal, oral, or anal sex
  • prolonged face-to-face contact

Transmission may also happen through close contact with an animal that has mpox. For these reasons, people who have had contact with a person or animal with confirmed mpox may contract the infection themselves.

Whenever possible, people who have concerns about mpox should not try to self-diagnose. Instead, experts advise the following:

Speak with a doctor

The CDC asks any person with a new or unexplained rash, or other potential mpox symptoms, to contact a doctor.

People who do not have health insurance can contact their local health authority to find out how to access care near them.

Before a person visits a healthcare facility, they should call ahead to let staff know they may have mpox. If staff recommend visiting in person, the person can cover all areas of the rash with clothing or bandages and wear a face mask.

Get vaccinated

People can also contact a doctor if they have been in contact with a person or animal with mpox, even if they have no symptoms.

A doctor may be able to offer a person the mpox vaccine, which may reduce the severity of symptoms or prevent them entirely.

Ideally, a person should receive the mpox vaccine within 4 days of exposure to mpox.

Testing

If a person has mpox symptoms, the next step may involve testing for the disease. A doctor may recommend testing if a person has a rash that looks like mpox.

People do not need to order mpox tests themselves. A medical professional will arrange testing.

The mpox test involves swabbing the skin rash and sending the swab to a laboratory. The lab can determine whether the mpox virus is present.

Prevent transmission

If the test is positive, people need to take steps to prevent mpox transmission while they recover at home. This involves:

  • Covering the rash: Keep the rash covered with clothing or bandages and avoid scratching it. Do not pop the blisters. Popping them does not help them heal and can spread the infection. Avoid shaving the area until the scabs have fallen off and the skin has fully healed.
  • Isolating from others: Avoid close contact with other people. Do not share personal items, such as bedding, clothing, or towels. When avoiding contact is not possible, wear a face mask that fits well.
  • Frequent handwashing: Use soap and water or an alcohol-based hand sanitizer to wash the hands, especially before and after touching the rash or things that have touched it. Also wash the hands before using shared areas of the house, such as the kitchen or bathroom. If the rash is on the hands themselves, wear disposable gloves when in these spaces.

Let close contacts know

People need to let close contacts know if they have mpox as soon as possible. This includes people they see regularly and anyone they have been in close contact with since their first exposure to the infection.

Being aware of a potential mpox exposure allows people to watch for symptoms, isolate, take a test, and get vaccinated.

There is no specific treatment for mpox. However, most people get better on their own in 2–4 weeks. People can follow the above advice for preventing transmission of mpox until they recover.

People may also be able to ease symptoms by:

  • taking over-the-counter pain medications
  • using topical pain-relieving gels
  • trying antihistamines or calamine lotion to reduce itchiness
  • bathing in warm water with colloidal oatmeal
  • trying a sitz bath for rashes around the genitals
  • rinsing the mouth with salt water or medicated mouthwash, if the rash is in the mouth

For more severe symptoms, a doctor may recommend medications or vaccination for smallpox. The viruses that cause mpox and smallpox are very similar, so sometimes using smallpox treatments can help.

If someone has a weakened immune system, is severely ill, or is likely to become severely ill from mpox, treatment may involve the medication tecovirimat. This drug can help prevent mpox. Tecovirimat may also help relieve short-term symptoms, such as swelling and pain, as well as long-term symptoms, such as scarring.

Most people recover from mpox without any treatment. The outlook may depend on the strain of mpox virus a person contracts as well as other factors, such as the person’s overall health and ability to access healthcare.

Mpox does have the potential to cause complications, such as discoloration of the skin, or scarring, from the rash.

Swollen lymph nodes may suggest mpox if a person also has a rash and flu-like symptoms. The symptoms of mpox can develop up to 3 weeks after exposure to the virus, which could occur through sexual or nonsexual close contact.

Any person with a new or unexplained rash, or other potential symptoms of mpox, should speak with a doctor. Most people recover from mpox without treatment, but doctors may recommend a person get vaccinated to reduce the severity of the symptoms.