Whealing Response of Human Skin to Ultraviolet Light and the Histamine Theory of Allergic Reactions

Summary(1) The spectral response to light in a case of Urticaria solare may be connected with the pigmentation mechanism. (2) A process which produces a relatively non-diffusible whealing substance is probably responsible for the whealing in the case in question.The preceding observations, which will be reported in detail elsewhere, do not support the point of view that histamine or a readily diffusible H-substance of low molecular weight is responsible for the skin response to ultraviolet irradiation.