- Due to high vaccination coverage, measles and rubella (German measles) are now rarely seen in the Netherlands, which makes recognition of these diseases difficult. - Measles can also occur in people who have been immunized, as a result of vaccination failure. - Swift recognition of measles and rubella is necessary in order to manage them adequately and to prevent spreading of the disease. - Measles, rubella, and erythema infectiosum ('fifth disease') may result in complications during pregnancy. - Measles, rubella, scarlet fever, erythema infectiosum, and roseola ('sixth disease') can be difficult to differentiate. - In the Netherlands, diagnosis of a patient with measles or rubella, or of more than 1 patient with erythema infectiosum within one institution, must be reported to the local health authority within 1 working day. - Exclusion from school or a day-care facility is not required for any if the diseases discussed.