What does exanthem mean?
An exanthem is a widespread eruption or rash on the skin that typically arises as a symptom of an infectious disease. Classic examples include the rashes of measles, rubella, scarlet fever, chickenpox, and roseola, though many milder viral infections also produce them. The term is chiefly medical and clinical: a doctor might describe 'a maculopapular exanthem' to characterise both the appearance and distribution of a rash, while everyday speech would simply say 'rash'. The word derives from the Greek exanthēma, meaning a blossoming or breaking out, and shares its root with words like anthology and chrysanthemum — a poetic image of eruptions flowering across the skin. Its counterpart, enanthem, refers to similar lesions on internal mucous membranes. Related adjective forms include exanthematous, and the standard plural is exanthems or the more formal exanthemata.
nounA widespread rash or eruption on the skin, typically occurring as a symptom of an infectious disease such as measles, scarlet fever, or chickenpox.
- A widespread skin eruption or rash occurring as a symptom of an infectious disease or other systemic condition.
"The pediatrician identified the exanthem as a classic sign of roseola rather than a drug reaction."
"Measles produces a distinctive exanthem that begins behind the ears before spreading across the body."
"Many viral infections in children cause a mild exanthem that resolves without treatment within days."
Both plurals are accepted; 'exanthemata' reflects the Greek origin and is favoured in formal medical literature.
"Several childhood illnesses present with exanthemata that help distinguish one infection from another."
The word literally means 'a blossoming out' — doctors once described rashes as flowers breaking open on the skin, which is why it shares a root with chrysanthemum.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of exanthem
The word comes from the Greek exanthēma, meaning 'a breaking out' or 'blossoming', formed from exanthanein ('to burst into bloom'), itself built on anthos, 'flower'. It entered English via New Latin in the early modern period as physicians adopted Greek medical terminology. Its root anthos links it to cognates such as anthology, chrysanthemum, and anther.
Related word forms
How exanthem is actually used
Exanthem is a technical term used almost exclusively in medical and clinical contexts; lay speakers would simply say 'rash'. The plural is either exanthems or, more formally, exanthemata. The adjective form is exanthematous.
Easily confused with exanthem
An enanthem is a similar eruptive lesion occurring on mucous membranes inside the body, whereas an exanthem appears on the external skin.
Exanthema is essentially the same word in its fuller Greek-derived form (plural exanthemata) and means the same thing; it is a variant rather than a distinct term.