Fibrinoid necrosis and downward motion of colloid bodies in lichen planus (apoptosis).

Fibrinoid necrosis which in previous investigations was demonstrated in the epithelial cells of the skin and of the liver in certain disorders, may also appear in the colloid bodies in lichen planus. Trichrome stainings were positive for fibrinoid, staining reactions with haematoxylin variants indicated the presence of keratin and precursors, and investigations in Wood's light permitted conclusions concerning the appearance of mixed proteins, of which keratofibrinoid seems to be the most important. Circulatory disturbances are emphasized as having an important role. The colloid bodies are extruded from the epidermis, according to the observations of Kerr et al., following the rules of apoptosis.