Increasing attention has recently been focused on a group of conditions characterized by a widespread alteration of the collagenous tissue. Active vasculitis of various regions appears to be, among other characteristics, a fairly constant common denominator in this group of diseases which includes such heterogeneous conditions as disseminated lupus erythematosus, acute glomerulonephritis, polyarteritis nodosa and serum sickness. Some of these conditions have a possible allergic causation, while in others the pathogenetic mechanism is obscure. Recently an additional characteristic has come to the fore, i. e., a variably favorable response to treatment with anterior pituitary adrenocorticotropic hormone (ACTH).1
The nonthrombopenic Henoch-Schönlein type of vascular or anaphylactoid purpura is another condition which may be related to this group in view of its possible allergic basis and its severe generalized vasculities. The classic capillary lesions are represented by active inflammatory changes centered around the smallest vessels with infiltration of inflammatory cells, and