Mpox and genital herpes can both cause painful sores on or near the genitals, but they're different infections with different culprits — mpox comes from the monkeypox virus, while herpes comes from HSV-1 or HSV-2. Mpox lesions tend to be firm, deep, and dimpled in the center; herpes sores cluster as small, shallow blisters. In practice, only a swab test tells them apart.
vaccine + tecovirimat
lifelong; antivirals control, not cure
| Item | Value |
|---|---|
| Mpox | curable — vaccine + tecovirimat |
| Genital herpes | managed — lifelong; antivirals control, not cure |
What each one is
Mpox
Mpox is a viral illness caused by the monkeypox virus, a relative of the smallpox virus. The clade II strain drove the global outbreak that began in 2022, spreading mainly through close skin-to-skin contact — including intimate and sexual contact — and affecting mostly men who have sex with men CDC. Most people recover fully on their own, but the illness can become severe in people who are immunocompromised, such as those with advanced HIV.
Genital herpes
Genital herpes is caused by two viruses: herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) CDC. It's extremely common and, unlike mpox, it's lifelong — the virus stays dormant in nerve tissue and can reactivate. Most people with HSV-2 have no or very mild symptoms, never know they carry it, and the majority of infections go undiagnosed. That's a key difference: a herpes infection often hides for years, while an mpox infection announces itself with an acute, self-limited rash.
Symptoms compared
Both can produce sores in the genital or anal area or the mouth, which is exactly why they get confused. Here's how each tends to behave.
Mpox typically starts with a rash that can look like pimples or blisters — often painful or itchy — on the hands, feet, face, mouth, genitals, or anus CDC. Lesions frequently land in the genital or anal area or the mouth, especially in sexually acquired cases. The rash may come with fever, swollen lymph nodes, muscle aches, exhaustion, and respiratory symptoms. Some people get the rash with no warning prodrome at all.
A first herpes outbreak usually brings blisters that break open into painful sores, which take a week or more to heal, sometimes alongside flu-like symptoms such as fever, body aches, and swollen glands. Sores show up on or around the genitals, rectum, or mouth. Repeat outbreaks are shorter and milder, and many people feel a prodrome — tingling, itching, or burning — before sores appear.
How to tell them apart
The single most useful distinction is lesion morphology — how the sores actually look. Mpox lesions are classically firm, often umbilicated (a small dimple in the center), and may feel deep and rubbery; they can appear scattered and at different stages. Herpes sores are typically clusters of small, shallow, fluid-filled vesicles on a red base that quickly ulcerate and crust together in one area. The systemic picture also differs: prominent swollen lymph nodes and a rash that spreads to hands, feet, or face point more toward mpox than herpes.
Honest caveat: the overlap is real. A solitary genital ulcer, a painful cluster, fever, and tender glands can fit either one — and many cases don't read like the textbook. You usually can't tell these apart by feel or by a glance in the mirror. A swab test is what settles it, and getting that test is the right move rather than guessing.
Mpox vs herpes at a glance
| Mpox | Genital herpes | |
|---|---|---|
| Cause | Monkeypox virus (smallpox family) | HSV-1 or HSV-2 |
| Typical lesion | Firm, deep, often dimpled (umbilicated); pimple- or blister-like | Clusters of small, shallow vesicles that ulcerate |
| Where | Genitals, anus, mouth, plus hands, feet, face | Genitals, rectum, mouth |
| Systemic signs | Fever, swollen nodes, muscle aches, exhaustion, sometimes respiratory | Flu-like illness mainly in the first outbreak |
| Course | Acute, self-limited; most recover fully | Lifelong; can recur |
| Diagnosis | PCR for viral DNA from a lesion swab | Type-specific NAAT or culture from a lesion swab |
| Treatment | Supportive care; antiviral for severe/high-risk cases | Antivirals control symptoms; no cure |
Testing
Both are confirmed by swabbing a sore — there's no reliable way to diagnose either from symptoms alone. Mpox is confirmed by detecting mpox virus DNA by PCR from a swab of a suspected lesion. If you want the full workflow, see our guide to mpox testing.
When herpes lesions are present, the standard is type-specific virologic testing of the lesion by NAAT or culture, and swab-based tests work best while the sore is fresh CDC. Practically, testing might mean a quick exam, a self-collected swab, or a urine sample depending on what's suspected, and it's available free or low-cost at health departments, Planned Parenthood, and Title X clinics. If you have an active sore, don't wait — you can get tested while it's still present, since healed lesions are much harder to confirm. If you were exposed but have no sores yet, our page on when to test after exposure explains the timing.
Treatment compared
Most people with mpox who don't have severe disease recover with supportive care and pain management. The antiviral tecovirimat (TPOXX) is considered for severe disease or for people at high risk, such as those with advanced HIV, through CDC access; trials found it safe but it did not speed lesion healing CDC. So mpox treatment is largely about comfort and watching for complications, not a routine prescription.
Herpes is managed with three FDA-approved antivirals — acyclovir, valacyclovir, and famciclovir — which control symptoms and shorten outbreaks but do not cure the infection CDC. Some people take them only during flares; others take them daily to suppress recurrences. Daily therapy also protects partners: in a randomized trial of serodiscordant couples, suppressive valacyclovir lowered the risk of passing HSV-2 to a partner by about 48% Corey et al.. For readers exploring non-prescription options, we cover alternative herpes treatments separately.
Can you have more than one at once?
Yes. Mpox and herpes spread through the same kind of close, intimate contact, so it's entirely possible to carry both — and a single mpox sore doesn't rule out coexisting herpes, or vice versa. This matters because herpes can be silently active even without symptoms: people with HSV-2 shed virus on about 10% of days even when they never have an outbreak, and most of that shedding leaves no visible sore JAMA. That's why a clinician may test for more than one cause when sores show up, rather than assuming the obvious lesion explains everything.
When to see a clinician
Get evaluated promptly if you develop new genital, anal, or oral sores — especially with fever, swollen lymph nodes, or a rash spreading to your hands, face, or feet, which raises concern for mpox. Seek care urgently if sores are severe or rapidly spreading, if you can't eat or pass urine or stool because of pain, or if you're immunocompromised, since both infections can be more serious in that setting. Until you have a diagnosis, avoid skin-to-skin and sexual contact, because both spread that way.