THE cause of lichen planus is still unknown, but various theories regarding it have been advanced. They include the nervous, the infectious, including the focal infectious, the toxemic and the constitutional diathetic theory. Lichen planus has also been called a syndrome; this, of course, concedes a possible causal importance to all the factors mentioned and allows the inclusion of the lichen-planus-like toxicodermas. All these theories have been comprehensively discussed by F. Juliusberg.1
The experiments reported in this paper are based on the infectious theory, which is supported by certain clinical and experimental experiences, by certain therapeutic reactions and by observations which suggest contagiousness. The necessity of keeping this paper as short as possible prevents us from entering into a more detailed discussion of these and related factors with reference to the literature concerned.
Extending full consideration to the other hypotheses mentioned, one of us (Biberstein)
HANS BIBERSTEIN, JACOB WACHTEL. IMMUNIZATION THERAPY FOR LICHEN PLANUS. Arch Derm Syphilol. 1946;53(4):355–364. doi:10.1001/archderm.1946.01510330053005