The first signs of mpox are usually flu-like symptoms: fever, headache, chills, exhaustion, and swollen lymph nodes. These typically appear about 5 to 6 days after exposure, though the incubation period can range from 3 to 21 days. Within 1 to 4 days of those initial symptoms, a distinctive rash develops.
The Earliest Symptoms Before the Rash
Mpox typically starts with what doctors call a prodrome, a brief window of general illness before any skin changes appear. During this phase, which lasts roughly 1 to 2 days, you may notice fever, muscle aches, headache, sore throat, cough, or a deep sense of fatigue. These symptoms alone aren’t enough to distinguish mpox from the flu or dozens of other infections.
The key early sign that sets mpox apart is swollen lymph nodes. This swelling can show up in your neck, jaw area, armpits, or groin, and it may affect one side of the body or both. Swollen lymph nodes are the single most useful clue before the rash arrives, because most look-alike illnesses (chickenpox, shingles, syphilis) don’t cause significant lymph node swelling. The swelling typically appears 24 to 48 hours before skin lesions break out.
That said, many recent cases, particularly the milder Clade II strain circulating since 2022, have skipped the prodrome entirely. Some people develop localized lesions with no fever, no fatigue, and no warning. If you’ve had a known exposure, the absence of flu-like symptoms doesn’t rule mpox out.
What the Rash Looks Like at Each Stage
The rash moves through a predictable sequence over two to three weeks, and each stage has a distinct look:
- Flat spots (days 1 to 2): The rash starts as flat, discolored patches on the skin.
- Raised bumps (days 2 to 4): Those flat spots become firm, raised bumps.
- Fluid-filled blisters (days 4 to 6): The bumps fill with clear fluid.
- Pus-filled pustules (days 6 to 13): The fluid turns opaque and the lesions become firm, round, and deeply rooted in the skin. A small dent forms in the center of each one.
- Scabs (days 13 to 27): The pustules crust over and eventually fall off.
One hallmark of mpox is that all lesions on a given body area tend to be at the same stage simultaneously. If you see bumps, blisters, and scabs all mixed together in one spot, that pattern fits chickenpox more than mpox. Mpox lesions also feel deeper and firmer than chickenpox blisters, which tend to be superficial with irregular edges.
Where the Rash Appears First
In classic mpox infections, the rash tends to start on the face and then spread to the arms and legs, including the palms of the hands and soles of the feet. Lesions on your palms and soles are a notable feature, since most common rashes spare those areas.
In the 2022 outbreak and beyond, though, the pattern shifted. Because many infections spread through close intimate or sexual contact, the first lesions frequently show up on or near the genitals, around the anus, or in the mouth. The location of initial lesions correlates with the type of contact. People who had receptive anal contact, for example, were more than five times as likely to develop rectal inflammation as an early symptom. In many of these cases, anogenital lesions appeared first, before any rash spread to other parts of the body. Some people developed only a handful of localized lesions and never got a widespread rash at all.
How Mpox Differs From Chickenpox and Shingles
Chickenpox lesions are shallow, have irregular borders, and move through their stages fast, going from flat spots to scabs within about 24 hours. At any given time, you’ll see lesions at many different stages all mixed together. Mpox lesions are the opposite: deep, well-defined, round, and slow-moving, with each stage lasting one to two days. And again, swollen lymph nodes are characteristic of mpox but not chickenpox.
Shingles, caused by reactivation of the chickenpox virus, produces a painful rash that follows a single nerve path, usually wrapping around one side of the torso or appearing on one side of the face. Mpox doesn’t follow nerve paths and tends to appear on both sides of the body. Shingles is also most common in people over 60, while mpox has no strong age pattern.
Clade I vs. Clade II: Do Symptoms Differ?
Two main viral clades are circulating globally. Clade II (specifically Clade IIb) drove the 2022 worldwide outbreak and generally causes milder disease with a fatality rate below 1%. Many Clade IIb infections present with just a few localized lesions and little to no fever.
Clade I, found primarily in Central Africa, is more virulent, with historical fatality rates between 1% and 10%. A newer subtype called Clade Ib has raised particular concern because it combines higher virulence with greater person-to-person spread. Clade Ib cases tend to present with a more widespread, full-body rash or persistent genital lesions, and are more likely to include the classic prodromal fever and lymph node swelling before the rash.
Regardless of clade, the core symptom progression is the same: systemic illness, swollen lymph nodes, then a rash that evolves through defined stages. The differences are mainly in severity and how many lesions develop.
When You Become Contagious
You can spread mpox from the moment symptoms begin, including during the prodromal phase before any rash is visible. You remain contagious until every lesion has scabbed over, the scabs have fallen off, and fresh skin has formed underneath. That process typically takes two to four weeks from the start of the rash. During this entire window, the virus can spread through direct skin-to-skin contact with lesions, contact with contaminated materials like clothing or bedding, and prolonged face-to-face contact that allows respiratory droplets to transmit.
Because some people skip the prodrome and go straight to lesions in areas that aren’t immediately visible (genitals, rectum, throat), they may not realize they’re infectious until days into the illness. Rectal pain, pain with swallowing, or the appearance of even a single unusual sore in the genital area after a potential exposure warrants testing.