Hypocomplementaemic urticarial vasculitis, angio-oedema and 'lupus-like' disease: association with C4B null allele.

A patient who presented with urticarial vasculitis, recurrent angio-oedema and gastro-intestinal symptoms in association with a 'lupus-like' disorder is documented. Other 'auto-immune' phenomena such as Sjogren's-like syndrome and polyarthritis were present in association with antibodies to RNP, low C4 and a null allele was demonstrated at the C4B locus. Response to varied therapies was poor and unsustained.