1223 How often do measles patients have ‘classical’ signs of the disease?

A simple but elegant study was carried out by dermatologists at the University of Cape Town who exploited the recent 2009-11 measles outbreak (>18 000 cases) by studying so-called characteristic signs of measles in children admitted for management of more-severe disease. In the ‘classic’ form the rash appears on the third or fourth day of illness at the hairline and behind the ears, then progresses inferiorly. The rash consists of erythematous macules on the face, and is typically morbilliform over the rest of the body. For the purposes of this study the ‘classic dermatological measles syndrome’ included Koplik spots, other oral manifestations of stomatitis, conjunctivitis and a morbilliform rash with cephalocaudal spread. Other manifestations such as fever, coryza, cough, diarrhoea, croup and secondary infections such as pneumonia may have coexisted in varying combinations. An atypical measles syndrome may arise with wild-type infection after immunisation with inactivated vaccine, and a modified form of measles may also arise with post-exposure prophylaxis with immunoglobulin and in young infants who retain a level of maternal antibody. Malnutrition and co-infection with HIV may also affect the presentation of measles through interference with immunity. In this particular study the primary objective was to assess the frequency of presentation with skin signs compatible with a classic dermatological measles syndrome in laboratory-confirmed cases that had been admitted to the measles-dedicated wards. Sixty-nine patients were recruited (34 males, median age of the group - 6 months) of which 41 were tested for measles IgM and 38 were positive, indicating a high rate of clinical diagnostic accuracy. HIV and malnutrition were respectively noted in 1 and 9 of the group of 69, an occurrence rate that was too low to assess the impact of these conditions on measles presentation. However of note were the following: only 17.4% of the 69 conformed to the definition of classic dermatological measles and only 26.3% of those positive for measles IgM presented with the classic picture. Only 3 with a positive test result had Koplik spots, while 12 had typical oral manifestations. Conjunctival involvement, morbilliform rash, and cephalocaudal spread were noted in 65-80% of cases, with combinations of two of the latter occurring in 50-60%. Another frequent dermatological manifestation was skin necrosis in 56% of confirmed cases. Since the study only covered admitted patients it is possible that different results might be found in ambulant measles patients, and it would also be interesting to know whether maternal immune status (for measles and possibly also HIV) plays a role in how the infants present.

Read more:
S Afr Med J 2012; 102: 356-9
PLoS Pathog 2011; 7: e1001241
Clin Vaccine Immunol 2006; 13: 437-43