Monkeypox — officially renamed mpox by the World Health Organization — and chickenpox can look strikingly similar at first glance, since both cause a blistering rash accompanied by fever and body aches. But they’re caused by entirely different viruses, spread in different ways, and produce rashes that behave differently as they progress. Telling them apart matters both for treatment and for understanding how each disease spreads, though a healthcare provider should always confirm a diagnosis rather than relying on visual comparison alone.
Different Viruses Entirely
Despite the similar-sounding “pox” in both names, these are unrelated viruses. Chickenpox is caused by the varicella-zoster virus (VZV), a member of the herpesvirus family that can also reactivate later in life as shingles, particularly in people over 50 or those with weakened immune systems. Mpox is caused by the monkeypox virus, a member of the Orthopoxvirus genus — the same family that includes smallpox. This distinction matters clinically, since it means the two illnesses respond to different treatments and vaccines.
How Each One Spreads
Chickenpox is highly contagious and spreads primarily through respiratory droplets, meaning simply being in the same room as an infected person can be enough to catch it, along with direct contact with fluid from the blisters. Mpox spreads mainly through close physical contact with an infected person’s skin lesions, bodily fluids, or contaminated materials, and it can also spread from infected animals to humans — reflecting its origins as a zoonotic disease first identified in animals before jumping to humans.
Comparing the Rash Itself
The rash is often the most noticeable difference between the two conditions once you know what to look for:
- Timing of outbreak: Chickenpox lesions appear in waves — new spots keep showing up on different parts of the body over several days while older ones are already scabbing. Mpox lesions tend to develop all at the same time and progress through their stages together.
- Size and depth: Mpox lesions are typically larger and go deeper into the skin than chickenpox blisters.
- Sensation: Chickenpox blisters are usually described as intensely itchy, while mpox lesions are more often described as painful.
- Duration: Chickenpox sores generally resolve within about two weeks, while mpox lesions can take two to four weeks to fully heal.
- Distribution: Chickenpox commonly starts on the trunk and spreads outward. Mpox lesions can appear on the face, mouth, hands, feet, and genitals, and may be widespread or limited to just a few spots depending on the case.
A Key Distinguishing Symptom: Swollen Lymph Nodes
One of the more reliable clues doctors use to distinguish the two is lymphadenopathy — swollen lymph nodes. This symptom is common in mpox but is not typically seen in chickenpox, making it a useful, though not definitive, sign when trying to tell the two conditions apart.
Treatment Differences
Chickenpox treatment generally focuses on managing symptoms — antihistamines and calamine lotion to reduce itching, and over-the-counter pain relievers for fever and discomfort. Antiviral medication may be prescribed in severe cases or for high-risk patients if started early. There’s currently no antiviral medication specifically approved for mpox, but doctors may use tecovirimat (originally developed for smallpox) or cidofovir in patients who are severely ill, pregnant, or immunocompromised. Vaccinia immune globulin, an antibody treatment derived from smallpox-vaccinated donors, is another option in severe cases of either illness.
Current Global Status
Mpox has drawn significant international attention in recent years. The World Health Organization declared mpox a public health emergency of international concern in August 2024, driven by an unprecedented outbreak centered in Africa. This followed an earlier 2022 mpox outbreak that was also declared a public health emergency both in the U.S. and globally. Chickenpox, by contrast, remains one of the most common childhood illnesses worldwide, though its prevalence has dropped substantially in countries with routine varicella vaccination programs.
When to See a Doctor
Because mpox and chickenpox rashes can look alike — and can also resemble other conditions like measles — a healthcare provider will typically want to test for multiple possibilities rather than diagnose based on appearance alone. Anyone with a new blistering rash, especially alongside fever or swollen lymph nodes, or who has had potential exposure to mpox, should contact a healthcare provider for proper testing and guidance rather than trying to self-diagnose.
Join The Discussion
Mpox’s rise in visibility over the past few years has made distinguishing it from more familiar illnesses like chickenpox increasingly relevant for a lot of people. Have you had questions about telling these two conditions apart, or experience navigating a diagnosis for either one? Share what you’ve learned, questions you still have, or resources that helped you understand the differences.
