Immune complexes in patients with drug eruptions: the relationship between skin lesions and circulating immune complexes.

The relationship between skin lesions and immune complexes was studied in sixty-two patients with exanthematic drug eruptions. By means of C1q-binding, conglutinin-binding and platelet aggregation tests, immune complexes were detected in a considerable number of sera from these patients. Patients with widespread maculopapular drug eruptions were found to show a relatively high serum level of immune complexes. There was a close association between the disease activity and the amount of the circulating immune complexes. By immunofluorescence, six of seventeen patients with drug eruptions were shown to have deposits of IgG, IgM, IgA or C3 in the skin lesions. These results suggest that certain immune complexes may play a role in some types of drug eruption as a pathogenetic factor.