Suggest Treatment For Angieodema In An Infant

my 16 month old daughter has angieodema, antihistermines are not making it any better. since shes been born she has always got bad laryngitus and loses her voice and often stops breathing when she cries so we have to blow in her face to make her breath. she is always coming out in a rash that is unexplained and doctors dont seem to know what it is. i was told yesterday it is angioedema, however nothing else was said. could the laryngitus be part of this? and how am i meant to help her when the antihistermines are not working