Topical Surfactant-Induced Pruritus: Involvement of Histamine Released from Epidermal Keratinocytes

Abstract

Surfactants, an important component of cleansers, often cause itch in humans. Topical application of sodium laurate and Nlauroylsarcosine sodium salt to the skin of mice immediately (for 1-1.5 hours) increased scratching, and the former increased scratching again between 2 and 3 hours after application. Thus, we examined the mechanisms of sodium laurate-induced delayed scratching. Sodium laurate (0.1%-10%) increased delayed scratching and skin surface pH in a concentrationdependent manner. N-lauroylsarcosine sodium salt had no effect on these parameters, and sodium hydroxide solution did not increase delayed scratching. Sodium laurate-induced delayed scratching was markedly inhibited by the H 1 histamine receptor antagonist terfenadine, but it was not affected by mast cell deficiency. Sodium laurate application had no effect on the number of total and degranulated mast cells, and did not induce plasma extravasation or the infiltration of inflammatory cells in the skin. Sodium laurate application increased the histamine content of the epidermis, but not that of the dermis, in normal and mast cell-deficient mice. Sodium laurate application increased the ratio of 53-kDa L-histidine decarboxylase (HDC, a key enzyme for histamine production) to 74-kDa HDC in the mouse epidermis and in a human keratinocyte culture. Sodium laurate increased histamine in the human keratinocyte culture, without affecting cell viability. The present results suggest that sodium laurate induced delayed scratching at an alkaline pH through the increased production of histamine in keratinocytes, which may be due to enhanced processing of 74-kDa to 53-kDa HDC.

Prevention of Topical Surfactant^|^ndash;Induced Itch-Related Responses by Chlorogenic Acid Through the Inhibition of Increased Histamine Production in the Epidermis

“…1A); the result was similar to our previous report (3). The effect of chlorogenic acid treatment on the scratching during a period of 2 -2.5 h after sodium laurate application was examined.…”

“…A topical dose of 5% chlorogenic acid might not be enough to exert anti-histamine effects in the dermis. Sodium laurateinduced scratching is not reduced by deficiency in mast cells (3). Therefore, the mast-cell stabilizing activity may not be involved in the inhibitory effect of topical chlorogenic acid on the sodium laurate-induced scratching.…”

“…Recently, we have found that a topical application of the anionic surfactant sodium laurate, but not the neutral surfactant N-lauroylsarcosine sodium salt, increases hind-paw scratching, an itch-related response, 2 h after application (3). The effect of topical sodium laurate is suppressed by an H 1 histamine-receptor antagonist and is attributed to histamine released from the epidermal keratinocytes (3).…”

“…The effect of topical sodium laurate is suppressed by an H 1 histamine-receptor antagonist and is attributed to histamine released from the epidermal keratinocytes (3). Mast cell histamine is not involved in this itching (3).…”

Methods for Preclinical Assessment of Antipruritic Agents and Itch Mechanisms Independent of Mast-Cell Histamine

“…Sodium laurate increased scratching again 2 to 3 h after application. 99) Twohours topical application of 10% sodium laurate significantly increased the pH of the skin surface from 5.1 to 6.0, but the pH nearly normal (pH 5.0-5.2) 2 h after the application of 10% N-lauroylsarcosine sodium salt. 99) Delayed scratching after sodium laurate application was markedly inhibited by terfenadine but not affected by mast-cell deficiency.…”