A 16-year-old male presents to his general practitioner with cough, rhinorrhoea, sore throat, fever and a rash. He has no significant past medical history and is on no medications. He has recently arrived from Romania and is a member of the Roma community.
His observations are heart rate 94 beats per minute, blood pressure 120/80 mmHg, respiratory rate 18/minute, oxygen saturations 97% on room air and temperature 39.2ÂșC.
On examination, there is a maculopapular rash affecting his face. His eyes have a serous discharge and small white lesions are noted on his buccal mucosa. There is no tonsillar exudate. There is no evidence of meningism. The cardio-respiratory and abdominal examinations are unremarkable.
What is the likely diagnosis?
- Epstein Barr Virus
- Measles
- Rubella
- Scarlet Fever
- Parvovirus B19
Measles is the correct answer. This patient presents with cough, coryzal symptoms, conjunctivitis and fever in association with a rash and Koplik spots, allowing his general practitioner to make a clinical diagnosis of measles. Koplik spots (small white lesions on buccal mucosa) are pathognomonic for measles. There is a lower uptake of the measles, mumps and rubella vaccine in some groups (including members of the Roma community).
Measles is characterised by prodromal symptoms, Koplik spots. maculopapular rash starting behind the ears and conjunctivitis
Epstein Barr virus is incorrect. This can also cause fever and sore throat. While a rash can be present, it is a less prominent feature. There is often significant cervical lymphadenopathy. Koplik spots would not be present. Palatal petechiae may be seen early in infection.
Rubella is incorrect. This is another cause of a maculopapular rash affecting the face. There may be post-auricular and sub-occipital lymphadenopathy. However, Koplik spots will not be visible. Fever tends to be less prominent.
Scarlet fever is incorrect. The rash of scarlet fever caused by a streptococcal infection, which usually starts on the abdomen and spreads to the back and limbs. Sore throat is prominent and there may be tonsillar exudate. Cough is not a typical feature and there may be a ‘strawberry tongue’.
Parvovirus B19 is incorrect. This can cause a rash on the cheeks and occasionally a red, lacy rash that can be mistaken for measles. Koplik spots will not be present.
Measles is now rarely seen in the developed world following the adoption of immunisation programmes. Outbreaks are occasionally seen, particularly when vaccinations rates drop, for example after the MMR controversy of the early 2000s.
Overview
- RNA paramyxovirus
- one of the most infectious known viruses
- spread by aerosol transmission
- infective from prodrome until 4 days after rash starts
- incubation period = 10-14 days
Features
- prodromal phase
- irritable
- conjunctivitis
- fever
- Koplik spots
- typically develop before the rash
- white spots (‘grain of salt’) on the buccal mucosa
- rash
- starts behind ears then to the whole body
- discrete maculopapular rash becoming blotchy & confluent
- desquamation that typically spares the palms and soles may occur after a week
- diarrhoea occurs in around 10% of patients
Investigations
- IgM antibodies can be detected within a few days of rash onset
Management
- mainly supportive
- admission may be considered in immunosuppressed or pregnant patients
- notifiable disease â inform public health
Complications
- otitis media: the most common complication
- pneumonia: the most common cause of death
- encephalitis: typically occurs 1-2 weeks following the onset of the illness)
- subacute sclerosing panencephalitis: very rare, may present 5-10 years following the illness
- febrile convulsions
- keratoconjunctivitis, corneal ulceration
- diarrhoea
- increased incidence of appendicitis
- myocarditis
Management of contacts
- if a child not immunized against measles comes into contact with measles then MMR should be offered (vaccine-induced measles antibody develops more rapidly than that following natural infection)
- this should be given within 72 hours
