[Complement pattern in children with allergic-toxic exanthema--a contribution to differential diagnosis (author's transl)].

25 Sera from children with the clinical diagnosis: urticaria, allergic-toxic exanthema were examined for the complement components C3, C4 and C3-Activator. We applied the radial immunodiddusion. As controls served 50 helathy children and 25 children with morbili, rubeolae and scarlet fever. C3 was found to be decreased in 23 cases, C4 in 4 and C3-Activator in 19 cases of urticaria. This indicates the possiblity for the differential diagnosis, but children of the control groups did not show any consumption of one of the described complement components.