Investigation of a suspected outbreak of lipoatrophia semicircularis in children.

BACKGROUND AND OBJECTIVE: Recent reports of outbreaks of lipoatrophia semicircularis (LS) in various countries have generated discussion regarding the potential role of the environmental characteristics of office workplaces in new buildings. The objective of this study was to investigate a suspected outbreak of LS among children in a public school in Barcelona, which generated tremendous alarm.

METHODS: We performed an epidemiological assessment including descriptive and prevalence analyses, and an environmental investigation followed by a psychiatric assessment according to Small's criteria. We compared the prevalence of LS and its 95% confidence interval between children and staff attending the day-care centre under study and other centres.

RESULTS: Among 86 children attending a day-care centre we detected 11 confirmed and 2 possible cases of LS (15.1%) while among 41 children attending other day-care centres we identified 8 cases and 4 possible cases (29.3%) (P=.10). Among 12 day-care staff, we detected 8 cases of LS (66.7%) while among 19 women working different jobs we identified 14 with the same condition as the staff (73.7%) (P=.98). All lesions were finally classified as indentations with different locations. The environmental evaluation didn't identify any exposure factors with a significant role in the onset of the outbreak. The outbreak shared 13 of Small's 16 criteria regarding epidemic somatoform disorder ("mass hysteria").

CONCLUSION: The presence of indentations can be considered a normal variant in the lower extremities of children. The characteristic development of the process leads us to the conclusion that this outbreak was an epidemic somatoform disorder.