Outbreak of pneumonia and urticaria caused by Mycoplasma pneumoniae in two schools in a town of the Community of Madrid

Mycoplasma Pneumoniae causes mild respiratory infections in children and young adults. We present a pneumonia outbreak with related urticaria in some children in a village located in the south of the Community of Madrid. The majority of the cases were grouped in two schools, with 26 affected children in one school and 9 in the other. There were few cases in each class and few secondary cases in the families what can indicate, in this case, germ low infectiousity. We describe clinical symptoms, radiographic and analytic findings in these community- acquired pneumonias (CAP): all the cases had intense hacking cough, 14 (34.1%) children presented pneumonia without fever, 5 (12.1%) children had urticaria, only 2 children had polipnea (4.8%) and none of them had rhinitis. In the chest x-ray findings was a clear predominance of alveolar infiltrate in the lower lobes. None of the children had high white blood cell count nor high neutrophils count. One patient with hereditary haemolytic anemia had a haemolytic crisis coinciding with pneumonia. One patient suffered arthralgia, urticaria, leucopenia and neutropenia. There was a unique hospital admission. Twenty-one (51.2%) children were diagnosed by serological essays. A quick and easy serological test for IgM Mycoplasma pneumoniae antibodies could be a useful tool for diagnosis. In medical literature we have found few Mycoplasma outbreaks described in schools. The goal of this study is to describe the clinical appearance of M. pneumoniae infection in order to make easier its diagnosis and early treatment, attitudes that contribute to control the outbreak and lower the transmission between contacts.