Monkeypox: Clinical criteria

Clinical Criteria:

A clinically compatible illness characterised by the presence of acute unexplained* skin and/or mucosal lesions or proctitis (for example anorectal pain, bleeding).

*More common causes of acute rashes (see diseases with similar clinical presentation listed below) should be considered and excluded where possible.

Clinical presentation

Monkeypox (MPX) classically presents with a prodrome with fever, aches and lymphadenopathy, followed by a characteristic centrifugal rash with the lesions first appearing on the face and moving to distal extremities. The rash also progresses through four stages simultaneously from macules to papules, vesicles then pustules, followed by scabbing.

In the 2022 outbreak, presentations of monkeypox have been atypical:

  • The rash/lesions may be localised to ano-genital skin, or oropharynx or rectal mucosa (proctitis)
  • There may be a solitary lesion
  • The rash/lesions may not necessarily progress through four stages as described above
  • Systemic symptoms may be absent or have developed after the onset of rash.

The clinical presentation is similar to diseases that are more commonly encountered in clinical practice, such as hand foot and mouth disease, varicella zoster, herpes simplex, syphilis and molluscum contagiosum. As a result, more common causes of acute rashes with similar appearances should be considered and excluded where possible.

However, co-infections have occurred sporadically, and given the evolving epidemiology of monkeypox, patients with a rash suggestive of monkeypox should be considered for testing, even if other conditions are likely.

For more information refer to the Monkeypox section of the Communicable Disease Control Manual.