354 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS lßlTlIll Figure 2. Optical photomicrograph of skin having dryness rating of 3 distribution of scale and cracking. Gross signs of dryness, which are visible to the naked eye and the tactile evaluation of roughness are taken into account. II. Rating System A rating system has been developed in order to obtain a numerical expres- sion of relative dryness. The definitions of ratings from 0 to 5 are depicted in Table I. The +3 rating is a reference point, which relates the microscop"_c nu- merical rating system with the degree of dryness just noticeable to the subject. At low magnification (30 X), the skin surface of most subjects consists of diamond-shaped plateaus outlined by furrows or sulci (Fig. 1). Unless the skin is dry, beth plateaus and sulci are smooth in appearance. As the surface dries, scales appear on both plateaus and sulci (Fig. '2). Cracking occurs at the bottom of the sulci with advanced dryness (Fi, gs. 3 and 4). Relatively few in- dividuals (about 5 per cent), have skin in which the plateaus have a "cobble- stone" appearance. As a rule, this type of individual develops smaller scales than does the average individual, and these occur primarily on plateaus.

MOISTURIZING EFFICACY IN HUMANS 355 ! lmm •.:.:' .... •-:: .: ..-.... :...:,.•.•"•:...•...•.,•. ..•..•:•.•.:--'••••'.._.' .': ..•.•,:..•: •,.• .....: •' ..•.• •.• / .... .??? ..::: .• •-, ., '?:'..:/• '.. •::• " • : •' 7.%' ' .. '"':E" .?"." .,'...? ...... .... ß •. • :• •:. .•.....-. . ::• .-.• ..: • ..... .•. •.. .... .. ½ .:-::'• .:• •... ,.. :'•' .,,.:'•:' .:.•' ::..?'•' ':* ..• ..'•: ':•-•••••::.:,7 . ........ ' ..•--'?'" .:"" .•' ' ,/:, ..:_•.•... "•::•': '"'""'d'•2•7. ? .... •:•'.'• ."• :..:'• ' -.:-,: .-?' 'v• ......... "• "•'½ '•'"'""'-, "• .... • - ß '.%•, , ........ /' .:,: ..•..-'../,•?. ..:]" :•:..-....., ß .:'.½ .,. .¾, .: .• ½.•' • ." ,' . .•' ",7.'"' •½::.½j.•..,"•. . •. ......... .,/...,• .......... ....• ....... . :•.. ....... .•, ............ '•.. ,.•.. "•:':' ..•" ............. .. "•':.. ..•:"/•."" "• ':'•i'""'.•." !' ..::•:• :d• .. "• ....,. ½ ... ':'•,.:•" "'•':.]-' .......... ....-.. ....*-•-•½•,:•.•...½ •:.•..' • ::•....:?, .'.•?•½•:-. . ,.•.. ß ' .½'::..7..: .... :•,'.•.' .. • •.:...•... ½•:'. .•::-".:• :•..:. ' '.• '=:F:.=.¾, fZ. ' ....... -..'• .e.-'.--.' ' ". '...'..' • .... , '.• :.•-" -' ,..½,... . ...... •. ß '•.•••.••• ..,•.:..•.:,,. ..:..,•,. ,,•.'.%•,,,:::.•:•,•,,•..,......•.•?.•,:•.¾..,...•...,.. %•........ ....... •.....,,........ Figure 3. Optical photomicrograph o[ very dry skin having dryness rating o[ 5 lII. Test Procedure Both of each individual's hands are rated t•or initial dryness on the morning of the first test day using the scale described previously. Both hands are washed with unscented, 80:20 tallow cocoa hand soap 5 times per day at ap- proximately hourly intervals t•or 4 days. Hands are washed for 30 sec, so that the backs of both hands are equally exposed to lather. They are thoroughly rinsed with tepid tap water and patted dry, except for the backs of both hands, which are allowed to air dry. Following each of the first 4 washings,. the test material is applied to the back of one hand using the first 3 fingers of the opposite hand with a circular motion the other hand serves as the untreated control. Written instructions are given to each panelist at the start of the test. Pan- elists are cautioned not to transfer test material to the back of the untreated hand and to avoid rubbing or scratching either hand during the test period. The product is applied each day only after the first 4 •vashings. The fifth washing is necessary to remove the test material, which might interfere with