evaluation of a novel skin type meter and the correlation between fitzpatrick skin type and skin...
DESCRIPTION
Background and Objective: To evaluate a novel skin tone meter to categorise skin types into one of the six genres of the Fitzpatrick Skin Classification System, thus optimising safety in light-based dermatological procedures. The numerical classification schema measures several components; principally the reaction of human skin to exposure of ultraviolet light, which is used to help predict skin response in laser and intense pulsed light (IPL) treatments.Materials and Methods: 220 volunteers of mixed ethnic origin, age and gender were enrolled in this study. The subjects’ Fitzpatrick skin type was determined by a standardised questionnaire on their reaction to first significant sunlight exposure of the year. A calibrated prototype device consisting of an optical head (460 nm) and detector, microprocessor and an LCD display was used to measure the subjects’ inner arm skin, which typically has little UV exposure and minimal hair and compared with measurements using a skin colour chart and digital photographs. To evaluate device performance across different skin states using the same subject, a section of inner arm skin on a sub-group of eight subjects was marked into test areas using a template and the skin in each area prepared (i) with a control area (ii) by degreasing with acetone for 1 minute to represent dry skin, (iii) with a fine layer of coupling gel to represent hydrated skin, (iv) with a thin layer of petrolatum (Vaseline) to represent oily skin, (v) with saline solution applied and dried to represent dried perspiration. Results: Conclusion: This study demonstrated in vivo the potential for miscorrelation of the Fitzpatrick Skin Classification System to skin colour using assessed digital images of the measurement area against a skin tone chart. The novel device detects skin colour on simulated dry, hydrated, oily, and perspired skin. Through accurate detection of skin melanin, this novel device may significantly decrease the risk of potential side effects through overtreatment and extend treatment to wider patient populations with light based dermatological procedures.TRANSCRIPT
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Evaluation of a Novel Skin Type
Meter and the Correlation
between Fitzpatrick Skin Type
and Skin Colour
1. School of Medicine, Swansea University, UK
2. CyDen Ltd, Swansea, UK
3. Independent Laser Protection Advisor, Haywards Heath, UK
4. Molholm Hospital, Vejle, Denmark
Caerwyn Ash PhD1, Stuart Jones2, Godfrey Town3,
Marc Clement PhD1, Peter Bjerring MD PhD4,
Sam Webster PhD1, Richard Hugtenburg PhD1
Mike Kiernan PhD2
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Why is Skin Tone Important to Understand
Understanding and measuring epidermal melanin concentration
limits the output parameters of IPL/Lasers to prevent or severely
reduce the risk of adverse reactions
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Human Skin Optics
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Type 1 White: Always burns, never tans very pale
Type 2 White: Usually burns, tans eventually
known as Celtic skin, often has freckles.
Type 3 White: Sometimes burns tans quite well in
sunlight
Type 4 Moderate Brown: Hispanic/Mediterranean
skin, naturally darker olive skin tans well
Type 5 Dark Brown: cultural background is Asian Middle Eastern very sensitive to sunlight
Type 6 Black: Cultural background is Afro-
Caribbean and is very sensitive to sunlight
Skin Tone
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The Zebrafish Device
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The Study
Questionnaire
Swansea University Ethics Approved Study
120 Anonymised Subjects
Exclusion criteria = psoriasis, dermatitis
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The Study
Measurement Data
Zebrafish Measurement
Cortex RGB Measurement
Photo of treatment area
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Results
The results show no/limited correlation between the questionnaire
derived Fitzpatrick skin type and the self assessed skin tone.
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Results
Graph shows the correlation of the zebrafish prototype to the estimated skin type derived from the photographs of the Boots colour chart against measurement area.
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Results
Graph shows the correlation between the prototype zebrafish prototype and the RGB values of the Cortex DSM II ColorMeter.
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Results
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Results
Graph showing the variation of skin states on the Zebrafish prototype 4.5% Std Dev
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Results show that the zebrafish pigmentation index shows good correlation to a subjects skin colour.
Further, the results show that Pigmentation index is an improved method of determining IPL/laser parameters for cosmetic
IPL/laser treatments as it directly relates to the subjects melanin
concentration, intra-body melanin distribution.
The Fitzpatrick skin type was incorrect of 71.4% subjects using a Boots colour chart and genetic deposition key when compared to
a questionnaire derived Fitzpatrick value.
Fitzpatrick skin typing is not a good indication of the probability of adverse reactions using IPL/laser hair removal treatments.
Further testing is currently being undertaken
Discussion
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Summary Summary
1. Fitzpatrick skin typing is not optimal as a tool to determine
IPL treatment parameters.
2. Pigmentary Index is a better indication of the level of risk to
adverse reactions, we propose to use this index before
treatment even of different body locations
3. The Zebrafish system is proven to correlate with estimate
skin tone based on 120 subjects of various ethnicity, but
more work is required
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Consumer Diagnostic Devices
Consumer are familiar with diagnostic equipment
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Thank You