Mpox is a mild viral illness caused by infection with the mpox virus. It is usually a self-limiting illness with symptoms lasting for 2-4 weeks.
Incubation period is usually 7 to 14
days with a range of 5 to 21 days.
A person may have prodromal symptoms,
which can include:
- fever or chills
- headache
- myalgia
- arthralgia
- back pain
- lymphadenopathy
- fatigue
A maculopapular rash is typical of mpox, and develops 1 to 5 days after
initial symptoms, noting some people do not have prodromal symptoms. The rash often starts on the face
and spreads to other parts of the body. The rash may be generalised or localised, discrete or
confluent.
The rash usually evolves over 2-3 weeks, with progression of lesions classically
occurring as follows:
- macules (lesions with a flat base),
- papules (slightly raised firm lesions)
- vesicles (lesions filled with clear
fluid)
- pustules (lesions filled with yellowish fluid)
- lesions then scab over after 2-3 weeks, after which scabs fall off.
In the current outbreak, atypical
presentations have been observed, for example, patients presenting with no or a mild prodrome, or a rash with
few lesions or a single lesion only on the genital or peri-anal region. Some cases may present with proctitis (painful inflammation of the rectum) in the absence of an externally visible rash or lesion(s).
Hospitalisation is uncommon, and usually occurs for pain management, secondary skin
infections, or other complications. More severe complications of mpox infection can include cellulitis,
pneumonia, sepsis, encephalitis and corneal infection.