A topographical study of increased vascular permeability in passive cutaneous anaphylaxis in the chicken.

Passive cutaneous anaphylaxis was produced in chickens with bovine serum albumin (BSA) and anti-BSA chicken serum. Colloidal carbon was then given intravenously to identify the leaky vessels. Microscopic examination of cleared unstained skin revealed the topography of labelled vessels. The carbon labelling was confined to venules and small veins only. Examination of the time-course of permeability response revealed a biphasic pattern.