The period of active participation in the study for prepubertal subjects will be approximately 90 days, while that for pubertal/postpubertal subjects could be a maximum of approximately 270 or 360 days (3 separate active periods of approximately 90 days for those treated with icatibant during an attack; 4 separate active periods for those treated without an attack), with each active period separated by periods of inactive participation of variable duration.