Nonallergic factors in atopic dermatitis

Abstract

The nonallergic factors in atopic dermatitis are summarized. Atopic skin behaves as if it were in the state of “itchy skin.” The inherited tendency to cutaneous vasoconstriction is apparent in the response to change of temperature, to pressure, and to pharmacologic vasodilating agents, such as nicotinic acid and Mecholyl. Vasoconstriction is demonstrable in children, as well as in adults, and in individuals with strong atopic family histories but with no personal atopic disease. Elevations of values for acetylcholine, histamine, and norepinephrine in the atopic skin are discussed. Studies with dermal perfusion confirm the ready release of histamine from the atopic skin and emphasize that a pharmacologic difference may underlie the vasoconstrictor and pruritic responses. Atopic dermatitis may be related to ichthyosis, cataract, alopecia areata, agammaglobulinemia, Aldrich syndrome, and phenylketonuria. Useful genetic markers for the inherited factors in atopic disease may be more readily found in the associated disease pattern than in the external physical characteristics of the patient, and the atopic skin may be a pharmacologically unique hyperreactive skin that responds to many types of physical, chemical, and immunologic stimuli with pruritus.