Mpox is an infectious viral condition, whereas hives are a symptom of high histamine production or allergic reaction. Both conditions can cause bumps on your skin, but they differ in size, duration, and other associated symptoms.

Mpox is caused by a virus in the orthopoxvirus family. This is the same family of viruses that causes smallpox.

“Any ‘pox’ virus means that it produces boils or lesions on the skin, regardless of their severity,” said Anu Hazra, MD, an infectious disease specialist with Howard Brown Health in Chicago, Illinois.

Indeed, mpox is most known for causing painful, pus-filled, and potentially scarring lesions, rashes, and swelling, he explains.

Hives aren’t caused by a virus, nor are they typically contagious. Hives stem from elevated histamine levels, a chemical that communicates with your immune system.

If, for example, you come into contact with something you’re allergic to, your body will release higher-than-usual levels of histamine into your bloodstream.

Red, raised patches or bumps may develop as a result, causing itching and discomfort, explains Hazra.

An mpox-related rash starts with a handful of lesions that often look like pimples or cold sores, explains Hazra. These lesions turn into large blisters or pus-filled bumps that eventually scab.

“Hives are marked by a rash rather than a set of sores,” he said. “Hives also blanch, which means that when you press on them, the center of the bump turns white. Mpox lesions do not usually do that.”

Further, hives are primarily described as itchy. Mpox, on the other hand, can be itchy but is more commonly described as painful.

“Hives can appear and disappear rapidly, while mpox lesions are slow growing and slow to heal,” he said.

Mpox may also cause the following symptoms:

Approximately 20% of people — roughly 1 in 5 — develop hives at some point throughout their life, according to the American College of Allergy, Asthma & Immunology.

For many people, hives are related to contact with an allergen. Common examples include:

  • peanuts, eggs, nuts, and shellfish
  • aspirin, ibuprofen, and antibiotics, including penicillin and sulfa
  • insect bites and stings
  • latex
  • pet dander
  • pollen

Certain nonallergic factors can also result in hives. This includes:

  • bacterial infections, including urinary tract infections and strep throat
  • blood transfusions
  • exercise
  • exposure to cold or heat
  • exposure to sunlight
  • pressure on your skin
  • stress
  • viral infections, including the common cold, infectious mononucleosis, and hepatitis

None of these are risk factors for mpox. The virus is primarily transferred from person to person through skin-to-skin contact with mpox lesions.

“Someone recovering from mpox is contagious until the lesions scab up, the scabs fall off, and new skin has formed underneath,” explained Hazra. This can take anywhere from 7–21 days.

The virus can also be transferred through contact with objects and surfaces that someone with an active mpox infection has used and not disinfected. This includes clothing, electronics, linens, and pleasure products, to name a few.

Minimizing contact with any known allergens can help lower your risk of hives. If you frequently develop hives but are unable to pinpoint a specific trigger, Hazra recommends making an appointment with an allergy specialist.

They can perform a series of skin or blood tests to check for potential allergies in a safe, contained environment.

A healthcare professional may prescribe medications such as antihistamines or corticosteroids, depending on the results. Allergen immunotherapy (aka allergy shots) may also be an option.

Avoiding close or intimate contact with someone with an active mpox infection can help lower the risk of transmission. This includes:

  • prolonged face-to-face contact, including talking and kissing
  • hugging, massage, and other skin-to-skin contact
  • oral, anal, or genital sexual contact

There’s also an mpox vaccine that’s incredibly effective at helping reduce your symptoms should you come into contact with the virus, notes Hazra. Learn more about where to get the mpox vaccine here.

Usually, hives can be easily treated with over-the-counter (OTC) antihistamines, such as Benadryl, said Michelle Forcier, MD, a gender-affirming clinician with virtual healthcare service FOLX.

If you regularly get hives, she suggests working with an allergist to decide if allergy shots make sense.

Currently, no treatment will quell mpox the way Benadryl does hives.

“People with an active infection may be able to take OTC medications for pain, but the lesions cannot be treated with normal medication,” said Hazra.

The prescription drug tecovirimat (TPOXX) can be used to treat severe symptoms of mpox.

“You would need to see a primary care doctor or infectious disease specialist to be diagnosed with mpox and then prescribed TPOXX,” he said.

“Hives can, and typically do, reoccur,” said Hazra.

There’s also a risk of developing mpox again if you’re exposed to the virus more than once.

“Though, the odds of this happening are relatively small compared to experiencing hives twice,” said Hazra. “The second time you get mpox, you will likely experience much less severe symptoms.”

Oftentimes, hives — or a hive-like rash — can be treated at home with an oral antihistamine and OTC anti-itch cream.

Seek emergency medical attention if you experience:

  • difficulty swallowing
  • swelling in your mouth or throat
  • lightheadedness
  • racing heart

These additional symptoms suggest that you may have anaphylaxis, which can be deadly and requires immediate care.

You should also try to contact a healthcare professional as soon as possible if you have lesions that you think could be mpox. They may recommend an in-person appointment so that they can take a sample of the lesion for testing.

Gabrielle Kassel (she/her) is a queer sex educator and wellness journalist who is committed to helping people feel the best they can in their bodies. In addition to Healthline, her work has appeared in publications such as Shape, Cosmopolitan, Well+Good, Health, Self, Women’s Health, Greatist, and more! In her free time, Gabrielle can be found coaching CrossFit, reviewing pleasure products, hiking with her border collie, or recording episodes of the podcast she co-hosts called Bad In Bed. Follow her on Instagram @Gabriellekassel.