Measles

measles · rubeola · morbilli

A notifiable, highly infectious illness that is resurging in the UK - isolate the patient at the front door, then notify.

GPBand B

Red flags

Any breathing difficulty - pneumonia complicates 1 to 6% of cases on CKS's figures and is a standard reason for admission. (CKS ranks respiratory and gastrointestinal complications as the commonest overall; it makes no cause-of-death ranking, and nor does the Green Book or the WHO fact sheet, so none is claimed here)
Drowsiness, confusion, seizures or a severe headache - encephalitis
Dehydration from mouth ulceration and poor intake, particularly in a young child
Immunosuppression, pregnancy, an infant under 12 months, or an adolescent or adult - the Green Book states that measles case fatality is age-related, high under one year, lower from one to nine, and rises again in teenagers and adults. All of these need urgent specialist discussion
Failure to isolate the patient on arrival - the risk to other patients in the department is part of the clinical presentation

Recognise

On light skin

Erythematous maculopapular rash beginning at the hairline and behind the ears, becoming confluent and blotchy as it descends, in a miserable child with cough, coryza and conjunctivitis.

On brown and black skin

Measles in brown and black skin frequently does not look red, and the widely taught description of a blotchy red rash is one of the clearest examples of how a white-skin textbook fails. It more often appears as darker, violaceous or hyperpigmented macules and papules, and may be easier to feel than to see - palpate for the papular texture across the cheeks and hairline. Koplik spots on the buccal mucosa are entirely unaffected by skin tone and are worth looking for properly with a torch. Desquamation during resolution and prolonged post-inflammatory hyperpigmentation are both more conspicuous, and the hyperpigmented phase can persist for weeks.

In any skin tone

The prodrome comes first: three to four days of fever, cough, coryza and conjunctivitis before any rash
A miserable, unwell child - measles is not a mild illness
Koplik spots - small white spots on the buccal mucosa, present early and pathognomonic when seen
The rash descends from the head downwards and becomes confluent, unlike the discrete rash of rubella
Ask about immunisation status and travel or contact history, but remember that a vaccinated person can still get measles. Mind the Gap’s practical instruction for the measles rash in dark skin is to expose the trunk fully and use adequate lighting, and to look for a reddish undertone that may progress to a purple hue

Distribution

Starts behind the ears and on the face and hairline, then spreads downwards over three to four days to the trunk and limbs, becoming confluent. Fades in the same order, often with fine desquamation.

Photographs

The measles rash on brown skin. This is what it actually looks like - faint, flat, and easy to miss in poor light. Nothing here resembles th — The measles rash on brown skin. **This is what it actually looks like - faint, flat, and easy to miss in poor light.** Nothing here resembles the vivid red confluent rash of the textbooks. The whole trunk has to be exposed and good lighting used, and the rash may be easier to feel, as fine roughness, than to see. Do not let a subtle rash talk you out of measles in a child with fever, coryza and conjunctivitis.
Fitzpatrick IV-VI (Fitzpatrick type estimated from the photograph, not stated by the source) · Oladokun RE, Lehloenya RJ, Hlela C, Ubesie AC, Katibi SO, Malande OO, Eley BS · Atlas of Paediatric HIV Infection, UCT Libraries Press 2018 - Chapter 2: Viral Skin Infections, p44 · CC BY 4.0

Provenance for every photograph in this library: image licences. How much of the corpus still has no darker-skin photograph: skin tone coverage.

Mimics

Rubella — Rubella is milder, its rash is discrete rather than confluent, and there is no significant prodrome
Kawasaki disease — Both give fever, rash and red eyes; measles has cough, coryza and Koplik spots
Scarlet fever — Scarlet fever has a sandpaper texture and perioral pallor rather than a descending blotchy rash
Parvovirus B19 (slapped cheek disease) — Slapped-cheek disease is a well child with a striking facial rash and a lacy body rash
DRESS - drug reaction with eosinophilia and systemic symptoms — A morbilliform drug eruption looks similar; DRESS adds facial oedema, eosinophilia and organ involvement

What to do in the ED

Isolate immediately on arrival - a negative-pressure or single room, away from the waiting area, and mask the patient. This precedes clinical assessment
Notify the local health protection team the same day on clinical suspicion. Measles is a notifiable disease and notification does not wait for confirmation
Take an oral fluid sample or throat swab for PCR and salivary antibody as directed by the health protection team
Assess for pneumonia, encephalitis and dehydration - these are what make measles dangerous
Identify contacts who are pregnant, immunosuppressed or infants; post-exposure prophylaxis is time-critical and is arranged through the health protection team
Check and record immunisation status, and use the attendance to recommend MMR where indicated
Treatment is supportive; advise the family on isolation until four days after the rash appears

Disposition

Most previously well children are managed at home in isolation with supportive care and same-day notification. Admit or discuss for respiratory or neurological complications, dehydration, immunosuppression, pregnancy, an infant under 12 months, or an unwell adolescent or adult.

Safety-netting

Stay away from school, nursery and work, and avoid anyone pregnant or with a weak immune system, until four days after the rash appeared. Return immediately for difficulty breathing or fast breathing, drowsiness or confusion, a fit, a severe headache, or if the child cannot drink and is passing less urine. Phone ahead before attending anywhere so you can be isolated on arrival.

Sources

Open this entry in the interactive tool