A 15 month old white girl became unwell on the day after she received her MMR (measles, mumps, and rubella) and pneumococcal vaccinations. These had initially been booked when she was 13 months old but were postponed twice owing to minor illnesses.

On the day after her vaccinations she developed conjunctivitis, a cough, and fever, with gradual worsening of her symptoms over the next few days. Four days after the onset of symptoms, she refused food and had an episode of vomiting. The next day, small erythematous macules appeared behind her ears. Tiny white papules were present on the buccal mucosa. The eruption became papular and spread to her face, trunk, and limbs. The rash gradually became more confluent and maculopapular.

She was previously healthy but had contracted several minor infectious illnesses since starting nursery six months earlier. She had no known contact with anyone with a rash illness and no history of foreign travel. She lived with both parents and had no siblings.