Treatment of Hereditary Angioedema Prodrome with Recombinant C1-esterase Inhibitor (Ruconest)

After screening, subjects will be followed in the study for four consecutive prodromes. For prodromes designed to be treated with Ruconest, the drug will be administered within 12 hours of prodromal onset and prior to the onset of objective selling. Ruconset will be self-administered at home or by a healthcare professional at the recommended dose of 50 IU/kg body weight with maximum dose of 4200 IU as a slow IV injection over 5 minutes Subjects will be randomized into two arms after enrollment. Subjects in Arm A receives Ruconest after 1st and 2nd prodrome and no Ruconest after 3rd and 4th prodromes. Subjects in Arm B receive no Ruconest after 1st and 2nd prodrome and Ruconest after 3rd and 4th prodromes.