The disease met primarily in children, 90% of cases occur in age under 16. Meeting frequency 2, 30,000 in children. Older brother than older daughter (male/female ratio is 2/1).
The disease mainly encountered in children, 90% of cases occur in the age under 16. Frequency met 2 / 30,000 in children. Boys than girls (ratio of male / female is 2/1).