Primary Irritant Reactions Research Articles

Threshold Stimulation of the Skin and Housewives' Eczema of the Hands

In a previous study1on cutaneous sensibility threshold measurement with squarewave current, two significant findings were reported: (1) The range of sensibility thresholds was higher in men than in women, and (2) in women with housewives' eczema of the hands the sensibility threshold range was lower than in other women. It was felt that these differences in threshold sensibility were basically related to epidermal thickness rather than to neurological differences. Inasmuch as the outer epidermis acts as a protection against all outside irritants, it was felt that epidermal thickness would also influence the reaction to primary irritants. It was, therefore, theorized that in thin-skinned persons, the sensibility threshold would be relatively low and resistance to primary irritant would also be relatively low, resulting in a greater primary irritant reaction. The opposite course of events would be expected in relatively thicker-skinned persons. The

The Allergic Eczema-like Reaction and the Primary Irritant Reaction

Introduction Even though the eczematous response is perhaps the single most uniquely dermatologic form of reaction, only a limited amount of information is available with respect to its evolution and almost nothing is known about the histochemical changes which occur in its various phases. The reasons for this inadequate information are not a lack of interest or enthusiasm on the part of the dermatologists but rather practical difficulties which often hamper investigations in this field. In order to study the evolution of the eczematous response, i. e., the reaction characterized by intra- and intercellular edema, spongiosis, and intra-epidermal vesiculation in all its details, it becomes necessary to examine sections from the same skin area at close intervals. Only in such a way is it possible to gain that insight into the sequence of histopathologic events, the sum total of which might furnish a dynamic rather

Primary irritant and allergic eczematous reactions; their interrelations.

It is well known that eczematous skin reactions can be produced either by a primarily irritating substance or by an allergen. It will be the purpose of this paper to discuss the nature of the two types of eczematous reactions and their interrelations. An eczematous allergen is defined as a substance that is not primarily irritating on first exposure but which, in persons of the appropriate genetic constitution, causes the development of an allergic sensitization of the delayed type, so that subsequent contact with concentrations that are nonirritating to unexposed or nonsensitized persons produces an eczematous reaction. A primary eczematous irritant is defined as a substance which produces an eczematous response by nonimmunologic means. Primary irritants may be divided into two categories: (1) immediate, and (2) cumulative. An immediate primary irritant is the usual type. Here the eczematous reaction is produced on first exposure. The

Procedure for evaluating skin-sensitizing power of new materials.

WITH THE accelerated development of new drugs, cosmetics, dyes, and other materials which may contact the skin, there is an increased need for rapid screening methods for evaluating their sensitizing potentials. Animal tests have little utility, mainly because of species differences in sensitizability. The prophetic patch test procedure suggested by Schwartz and Peck 1 is of value but in some aspects is not entirely adequate for the purpose. In this test, the new material is applied to the skin for 48 hours under an occlusive patch; a group of 200 or more persons is used. The same group is retested in 14 to 21 days; new reactors are deemed to have been sensitized by the first patch test. Among problems encountered in carrying out this test is, first, the difficulty in distinguishing between allergic and primary irritant patch reactions. With threshold irritants, there may be variation from time to time