AKT · Child health/Infection & rash

Measles

Measles virus (paramyxovirus)

Overview

A highly contagious notifiable viral exanthem: prodromal fever, cough, coryza and conjunctivitis with pathognomonic KOPLIK SPOTS, followed by a cephalocaudal maculopapular rash. Resurgent with falling MMR uptake.

Recognise

Prodrome: high fever + the 3 Cs — Cough, Coryza, Conjunctivitis
KOPLIK SPOTS (white spots on buccal mucosa) — pathognomonic, precede rash
Maculopapular rash spreading from behind the ears/face downward, becoming confluent

Red flags

Complications: otitis media, pneumonia, encephalitis, (late) SSPE; immunocompromised/pregnant

Differentials & how to tell them apart

Rubellamilder, suboccipital/postauricular lymphadenopathy, no Koplik/3 Cs

Scarlet feversandpaper rash, strawberry tongue, GAS — responds to penicillin

Slapped cheek (parvovirus B19)slapped-cheek then lacy rash

Roseola (HHV-6)high fever THEN rash as fever resolves

Investigations

Clinical + salivary/serum measles IgM and RNA (oral fluid kit). NOTIFIABLE.

Management

Supportive care (+ vitamin A in young children)

1Notify. Supportive care; vitamin A for children (especially under 2). Exclude from school for 4 days after rash onset.
2Post-exposure: MMR within 72h or human normal immunoglobulin within 6 days for vulnerable contacts (pregnant, immunocompromised, infants).

Supportive — antipyretics, fluids

Vitamin A — in children, esp. <2 years

Human normal immunoglobulin — post-exposure prophylaxis for vulnerable contacts within 6 days

Key points

Koplik spots are pathognomonic and precede the rash. Notifiable. SSPE is a rare fatal late complication years on.

Monitor & prognosis

Complications (pneumonia, encephalitis); contacts.

Usually self-limiting; serious in malnourished/immunocompromised.

Source: NICE CKS Measles (2025); UKHSA