The histopathology of acute panniculitis nodosa leprosa (erythema Nodosum leprosum)

ABSTRACT

The histological features of 20 specimens of acute panniculitis nodosa leprosa (erythema nodosum leprosum) are studied. The most important feature is shown to be a panniculitis. The histological picture in P. N. L. is shown to be distinct from those of classical erythema nodosum, erythema induratum, sarcoid of Darier and Roussy, and the cutaneous form of polyarteritis nodosa, all of which conditions may bear a clinicl resemblance to P. N. L. Although P. N. L. occurs most frequently in treated cases, the lepromatous state is essential for its development. It is suggested that the term "panniculitis nodosa leprosa" describes more accurately the lesion now known as erythema nodosum leprosum.