Rash after measles vaccination: laboratory analysis of cases reported in São Paulo, Brazil

Abstract

ObjectiveThe clinical differential diagnosis of rash due to viral infections is often difficult, and misdiagnosis is not rare, especially after the introduction of measles and rubella vaccination. A study to determine the etiological diagnosis of exanthema was carried out in a group of children after measles vaccination. Methods Sera collected from children with rash who received measles vaccine were reported in 1999. They were analyzed for IgM antibodies against measles virus, rubella virus, human parvovirus B19 (HPV B19) using ELISA commercial techniques, and human herpes virus 6 (HHV 6) using immunofluorescence commercial technique. Viremia for each of those viruses was tested using a polimerase chain reaction (PCR). Results A total of 17 cases of children with exanthema after measles immunization were reported in 1999. The children, aged 9 to 12 months (median 10 months), had a blood sample taken for laboratory analysis. The time between vaccination and the first rash signs varied from 1 to 60 days. The serological results of those 17 children suspected of measles or rubella infection showed the following etiological diagnosis: 17.6% (3 in 17) HPV B19 infection; 76.5% (13 in 17) HHV 6 infection; 5.9% (1 in 17) rash due to measles vaccine. ConclusionsThe study data indicate that infection due to HPV B19 or HHV 6 can be misdiagnosed as exanthema due to measles vaccination. Therefore, it is important to better characterize the etiology of rash in order to avoid attributing it incorrectly to measles vaccine. Resumo Objetivo

Parvovirus B19 infections in state of Rio de Janeiro, Brasil: 526 sera analyzed by IgM-enzyme-linked immunosorbent assay and polymerase chain reaction

“…Positivities from 17 to 23% for B19 DNA by polymerase chain reaction (PCR) were also observed in sera of patients suspected of parvovirus B19 infection (Sevall 1990, Cassinotti et al 1993) and patients with arthritis of unknown origin (Cassinotti et al 1998). After the introduction of measles and rubella vaccination, the differential diagnosis of rash has been specially recommended, since 17.6% of the exanthema cases after measles vaccination were due to be caused by parvovirus B19 infection, in São Paulo, Brazil (Oliveira et al 2002b).…”

Etiologia de exantema em crianças em uma área endêmica de dengue

“…In this study, even using laboratory tests, it was impossible to elucidate the etiologic agent in all cases, probably due to the large number of microorganisms that cause this symptom. 2,[12][13][14] Currently Brazil is going through a process of eradicating measles and controlling rubella, in common with other countries. 3,7,15,16 Indeed, in our country the latest cases of measles to be reported have all been imported from abroad and the incidence of rubella is describing a downwards curve.…”

“…Infections by enterovirus, streptococcus or allergic reactions to medications are possible causes for the other inconclusive cases. 2,13,14 To illustrate the difficulties of diagnosis based on just data from the clinical examination of a child with exanthema, around 20% of the patients with dengue exhibited coughing or coryza, which are symptoms that characterize suspected cases of measles. Adenomegaly was present in 40% of dengue cases, while, in a study published by Oliveira in 2001, 12 this was 36.1%; among rubella cases there was an increased frequency (59.1%) of adenomegaly, but this was not considered a pathognomonic sign.…”

Parvovirus B19 Frequency in Exanthematic Cases Initialy Suspected as Measles or Rubella Infections in São Paulo, Brazil

“…Detection of outbreaks depends on the accurate diagnosis of a rash illness, Inaccurate diagnosis of such illness may result in disease spread, as well as inefficient use of limited resources, with shown by us in another studies at the Adolfo Lutz Institute and São Paulo University (Oliveira et al 2002).…”

“…However, atypical presentations are not uncommon and can lead to misdiagnosis (Cubel et al 1997, Oliveira et al 2002, Valero 2006. The differential diagnosis may also be ambiguous because of incomplete information from family members, particularly if the patient presents a rash after the classic prodrome of the measles, rubella or parvovirus B19, which increases the difficulty of accurate diagnosis based on clinical symptoms.…”