A NEUROLOGIC EVALUATION OF THE CUTANEOUS HISTAMINE REACTION 1

Abstract

The spreading flare phase of the triple response is absent following complete transection of a spinal nerve. The spreading flare is absent or markedly decreased in dermatomes below the level of complete transection of the spinal cord, and following isolation of the cord from nervous centers cephalad to the pons. Neither preganglionic sympathetic pathways nor the final common pathways are essential to the spreading flare. It is suggested that the axone reflex alone cannot subserve the neurogenic mechanism of the spreading flare, and this mechanism may include a suprasegmental reflex arc, the afferent arm of which reaches as high as the diencephalon or higher. The afferent and efferent impulses in this reflex travel via the dorsal nerve roots.