j. Soc.Cosmet. Chem.,35, 423-437 (December1984)
Photographic standardization of dry skin j. c. SEITZ, R. L. RIZER, andT. S. SPENCER,Dermal Research Department, S. C. Johnson andSon,Inc., 1525 HoweStreet, Racine, WI 53403.
Received July 13, 1984. Presented at theSCCAnnualScientific Meeting,New York, December 1983. Synopsis
Photographic reference standards weredeveloped to visuallyquantitatechanges in scaling,cracking,and erythema, themajorvisiblesymptoms of dry, chapped skin.Thesestandards wereshownto bereasonably precise whenusedby threeindependent readers to gradea setof dryskinclinicalslides.A pairedcomparison of replicatescoresfor eachjudge showedeither no significantdifferences or singleisolateddifferences dependent on the familiarityof the readerwith the scale.Uniformityof scoringbetweenreaderswas evaluated by analysis of variance.No significant difference wasobserved betweenthe two readersmost familiarwith the scale.A third inexperienced readerdifferedin scoring.However,all scoringtrendsfor this readerweredirectionallyin agreementwith the moreexperienced readersusingthe samescale.The reference standards permitthe useof clinical35-mmslidesfor bothdocumentation andquantification of
dry skin.Additionally,thephotographic reference standards permitblinded,independent evaluations of dry skin by independent readerswith lesssubjectivebias.
INTRODUCTION
In clinicalstudiesof dry skin, a needexistsfor photographic reference standards that arereasonably precise,easyto use,consistent from readerto reader,andcandocument the relativeefficacyof varioustopicaltreatments(1). Currently,in vivoevaluations of dry skin involvea varietyof narrativeordinalscaleswith semi-quantitative worddescriptorsto definethe degreeof dry skin severity.Kantoret al. (2) use 1 to 9 point scalesto quantifyscaling,cracking,and erythema,while Stanfieldet al. (3) employa ten-pointscalecombiningscaling;cracking,anderythema.Earlierdescriptions of dry skin havebeenproposedby severalauthors,and their definitionsdemonstrate that dry skinmeansdifferentthingsto differentobservers (4-7). Basically,existingscales and descriptions of dry skinrelyon the subjective judgementof theclinician,firstto classify the disorder,and thento recallfrommemorythe full rangeof dry skinobserved across manydaysand manystudiesto evaluatethe performance of a product. In the presentstudy, a zero to 10 grading systemwas developedfor scalingand cracking,anda zeroto 4 gradingsystemfor erythema.Thesegradingsystems arebased on photographic reference standards representing a spectrum of normalto severely dry, chappedskin on the dorsalaspectof the hand. Three independent readerswerethen testedfor accuracy and reproducibility usingthe photoreference standards to gradea setof clinicalslidestakenduring recentdry skin studies. 423
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MATERIALS
AND
METHODS
SUBJECTS
One hundredtwenty-twofemalesubjects,ages21 to 60, who wereproneto develop dry skin on the handswerephotographed during a dry skin studyin Tucson,Arizona. A secondgroup of 161 femalesubjects,ages21 to 55, underwenta soapand water challenge(6 washingsper day for 1 week) to induceseverelydry, chappedskin on the handsduring a hand lotion efficacystudyin ChicagoHeights, Illinois. 35-mm
MACRO-PHOTOGRAPHY
OF THE
HANDS
A Nikon F3 camera with a Micro-Nikor 105-mm macro lens, motor drive, bulk back,
right angle view finder, and shutter cable releasewas inversetripod mountedand bubbleleveled.The camerawasadjustedto a height of 60 cm from the table top to the film plate mark on the camerabody.
Two Novatron334 strobes(Novatronof Dallas,Dallas,TX) weresetperpendicular to the cameraat a 30-degreeincident angle, 1.5 metersfrom the centerof the field of view. Fill lighting was accomplished with a third Novatronstrobeset perpendicular to the main strobesat a 30-degreeangle, 1 meter from the field of view. The strobes were interconnectedto the synchronization terminal on the cameraand were balanced to f/16 with a Minolta FlashMeter III. Subjects'handswere photographed againsta blackvelvetbackground on an 8-degreeincline(Figure1). KodakEktachrome64 film wasusedat a shutterspeedof 1/80 of a second(8). All photographicprocessing was
Figure 1. 35-mm cameraand lighting systemfor macro-photography of the hands.
PHOTOGRAPHIC
STANDARDS
FOR DRY
SKIN
425
donein-houseon a commercial KodakE-6 processor according to the KodakE-6 Process Manual.Test film stripswererun to assurethe correctcolorbalanceand densityfor the Ektachrome64 film. For the Chicagoand Tucsonstudiesall film wasdeveloped in onebatchto furtherreducethe possibilityof subtlechangesin colorbalance. DETERMINATION
OF PHOTOGRAPHIC
STANDARDS
Photographic standards wereselected by reviewingover 1000 slidestakenduringthe ChicagoHeightsand Tucsonstudies.The normaland mostseverecases of dry skin werearbitrarilyassigned scoresof 0 and 10 respectively. Intermediategradesof untreateddry skin were selectedby an iterativeprocedureinvolvingtwo independent readers.Setsof six slidesincludingthe normaland mostseverecaseswerescoredby eachreader.Averagedscores for intermediate slidesthat deviatedfroman idealspacing of 0, 2, 4, 6, 8, and 10 (erythema0, 1, 2, 3, and 4) werereplacedand the scoring procedure wasrepeated. The setof slidesfinallychosen, portraying a rangefromnormal to severely dry, chappedskinwith overtscaling,cracking,anderythema,elicitedthe most consistentgrading response (Figures2-18). READER
REPRODUCIBILITY
Singlereaderreproducibility with the photographic reference scalewastestedfor each of threejudges.Eachjudgescoreda set of 46 randomlysorted,blind encodedslides
162
Figure 2. Scaling--Grade 0.
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223 Figure 3. Scaling--Grade2.
230 Figure4. Scaling--Grade 4.
PHOTOGRAPHIC
•,8
I
STANDARDS
FOR DRY
SKIN
427
i,i
140 .. .
Figure 5. Scaling--Grade 6.
•,8
I
I
Figure 6. Scaling--Grade 8.
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271
Figure 7. Scaling--Grade 10.
231 Figure 8. Cracking--Grade 0.
PHOTOGRAPHIC
STANDARDS
FOR DRY SKIN
OLZ' Figure 9. Cracking--Grade 2.
/47 Figure 10. Cracking--Grade 4.
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252 Figure 11. Cracking--Grade 6.
137 Figure 12. Cracking--Grade8.
PHOTOGRAPHIC
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FOR DRY SKIN
431
282 Figure 13. Cracking--Grade 10.
65
Figure 14. Erythema--Grade0.
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35
Figure 15. Erythema--Grade 1.
Figure 16. Erythema--Grade2
PHOTOGRAPHIC
STANDARDS
FOR DRY SKIN
Figure 17. Erythema--Grade 3.
•8
I
it
172 Figure 18. Erythema--Grade 4.
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taken from the Tucsonand ChicagoHeights studies.These test slideswere viewed side-by-sidewith the photographicstandards on Kodak 5600 projectorswith 102-mm Ektanar C lenses. The identical slides were resorted and rescored between one and three
dayslater. The replicatescoresfor eachjudgewereevaluatedby pairedcomparison. READER
UNIFORMITY
Multiple readeruniformity with the photographicreferencescalewas testedby an analysisof variancecomparingthe samethreejudges'scoringof an identicalsetof 46 slides(23 subjects).
RESULTS
A pairedcomparisonof scoresfor eachof the 3 readersshowedno significantdifferences betweenreadingpasses for Reader1, who wasthe mostfamiliarwith the photoscales. Isolatedsignificantdifferences wereobserved for Reader2, whohadminimalexperience scoringslideswith the scale(pass1 vs pass2 for crackingon slidesof the right hands), and Reader3, with no previousexperience(pass1 vs pass2 for scalingon slidesof the left hands) (Table I).
No significantdifferences werefoundbetweenReaders1 and 2, who weremostfamiliar with the scales.The newand inexperienced Reader,number3, showeda widervariance on all scales.Figures19-21 showthe meanscoresfor eachreaderplotted againstthe total numberof subjects.A wide rangeof dry skin conditionswererepresented in the slide set as shownby the wide fluctuationsin the curves.
DISCUSSION
The clinicalevaluationof dry skinrequiresquantitative,objectivetechniques to describe the visualassessments of the investigator.Until recently,however,investigators have offeredno explicit definitionof dry skin which will improvethe validity and reproducibilityof bioefficacytesting.The photographic reference standards help to visually
Table
I
Photographic Scores? of Dry Skin for ThreeIndependent Readers Reader
Scaling Pass 1
1 2
3
Pass 2
Cracking Pass 1
Pass 2
Erythema Pass 1
2.7
Right 3.3ñ 1.6 3.6ñ 1.6 2.5ñ 1.9 2.8ñ 2.0* 2.9 - 1.1
2.9 2.9
ñ ñ
1.2 1.3
Right3.7 + 2.5 3.7 ñ 2.6 2.2 3.0ñ 3.0 2.7 + 2.4 2.8 4. 1.1 3.1 4. 2.0 3.7 4. 2.1' ___2.6 2.0 ñ 1.7 3.0 ñ 1.3
2.9 ñ 3.1ñ
1.0 1.0
Left Left
3.4 ñ 1.2 3.1 ñ 1.5
3.4 ñ 1.2
3.4 ñ 1.7
2.9 -
1.2
2.1 ñ 1.5
2.9 ñ 1.2
2.2 ñ 1.4
2.9 4- 1.2
2.9 ñ 1.2
Left
? = Mean ___standard deviation.
* = Significantdifferenceby pairedcomparison betweenreadingpasses (c• < 0.05). n = 46.
Pass 2
Right 3.6- 1.8 3.6- 1.8 3.3- 1.7 3.3- 1.8 2.7ñ 1.2
4. 1.2
2.9ñ
1.1
PHOTOGRAPHIC
STANDARDS FOR DRY SKIN
435
5-
t
2
2
•
5
6
7
8
9
t0
tt
SUBJECT
AVERAGE
READER
t2
t2
t•
t5
t6
t7
t8
NUMBER
SCORES
t9
20
2t
22
22
•READER 1 0 READER 2 --&-READER 3
Figure 19. Parallelismof readerscoringof scaling.
5-
SUBJECT AVERAGE
READEP
NUMBER
SCORES
Figure 20. Parallelismof readerscoringof cracking.
• 0 --&--
READER READER 2 READER 3
2•
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0 ..• t
2
3
•• 5
6
7
8
9
•0
tt
t2
t3
•' •
•5
t8
t7
•8
t9
SUBaECT NUMBER
AVERAGEREADER SCORES
20
U 0
--&--
2t
22
23
2•
READER • READER 2
READER3
Figure 21. Parallelismof readerscoringof erythema.
quantitate changes in scaling, cracking, anderythema, thesymptoms ofdry,chapped skin.
The gradingsystem, anchored to photographic reference standards, wasconsistent within and betweenreaders.Reader 1, who was thoroughlyfamiliar with the photo
reference standards, demonstrated the bestreproducibility onsuccessive readingpasses. Readers 2 and3, with minimalor no previous experience, wereableto achieve good
reproducibility on repeated reading passes usingthephotographic scales. Although Reader 3 exhibited thehighest variation between readers, thescores weredirectionally correct overall subjects compared to Readers 1 and2. Theresults fromReaders 2 and 3 suggest thatsometrainingandfamiliarization withthescales arerequired. In summary, photographic reference standards provide a visualdefinition of scaling, cracking, anderythema. These standards permittheuseof clinical slides forboth documentation andquantification of a subject's dryskinstatus throughout thecourse of treatment. Moreover, photoreference standards permitblinded,independent evaluations of dry skinby independent readers with lesssubjective bias.Finally,these
photographic reference standards should provide a valuable teaching aidforclinicians andinvestigators whostudythesymptomatology ofvarious levels ofdryskin.
ACKNOWLEDGEMENT
The authorsthankDr. HarrySmith,Jr. for statistical advice.
PHOTOGRAPHIC
STANDARDS FOR DRY SKIN
437
REFERENCES
(1) C. H. Cook, R. L. Centher,and S. E. Michaels,An achegradingmethodusingphotographic standards,Arch. Dermatol.,115, 571-575 (May 1979). (2) I. Kantor, W. G. Ballinger,and R. C. Savin,Severelydry skin: Clinicalevaluationof a highly effectivetherapeutic lotion, Cutis,30, 410-424 (September 1982). (3) J. W. Stanfield, J. Levy,A. A. Kyriakopoulos, andP.M. Waldman,A newtechnique forevaluating bath oil in the treatmentof dry skin, Cutis,28, 458-460 (October1981).
(4) M. E. Chernosky, Clinicalaspects of dryskin,J. Soc.Cosmet. Chem.,27, 365-376 (August1976). (5) F. DanielsandJ. C. van der Leun, Problemsin quantifyingskin reactions, Arch.Derre.,97, 553565 (May 1968). (6) A.M. Kligman,Regression methodforassaying theefficacy of moisturizers, Cosmet. andTodet.,93, 27-35 (April 1978).
(7) T. B. Fitzpatrick,"Fundamentals of Dermatologic Diagnosis,"in Dermatology in General Medicine, 2nd ed., T. B. Fitzpatrick,A. Z. Eisen, K. Wolff, I. M. Freedberg,and K. F. Austin, Eds. (McGraw-Hill, New York, 1979), Part Two, pp 10-37.
(8) ClinicalPhotography, PublicationNumberN-3, (EastmanKodakCo., Rochester, New York, 1972), pp 21-64.
Editor'sNote:The authorswishto notethat colorreproduction of standards mightbe affected by mechanical reproduction andby the paperusedin printing.