Comparing Devices to Assess Facial Pigmentary and Inflammatory Conditions

Many dermatological conditions are assessed with the naked eye, including dermatoses that prominently feature erythema or pigmentary alteration. Disturbances of pigmentation include skin diseases such as melasma and dermatoheliosis as well as postinflammatory hyperpigmentation from inflammatory skin diseases such as atopic dermatitis and acne. Hypopigmented conditions of the skin include pityriasis alba, vitiligo, and postinflammatory hypopigmentation from conditions such as seborrheic dermatitis. When assessing these conditions, dermatologists may be unable to appreciate subtle changes in color or have difficulty assessing severity in patients with skin of color. Adjunctive tools such as polarized light, photography, Wood lamp, reflectance spectroscopy, and dermoscopy can help clinicians evaluate subtle pigmentary changes, but these techniques have some disadvantages.¹

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Limitations of Evaluation Methods

Validated outcome measures have been developed for pigmentary disorders (such as the Melasma Area Severity Index [MASI] for melasma), but they are sometimes difficult to perform quickly in a busy dermatology practice, and the subjective visual assessment may result in variability from different clinicians.² Despite these issues, dermatologists may still often use measures such as the MASI to evaluate pigmentary disorders such as melasma because there are not many other options to evaluate response to treatment or severity of disease.³ The main disadvantages of these traditional assessment methods include variability in interpretation and scoring between different clinicians.⁴

Precise measurements are not only critical for clinical practice but are even more important when developing and studying new medications and therapies for pigmentary disorders. Precision measurements, detecting even subtle changes or improvement in pigmentation, are necessary to improve on the current therapeutic armamentarium in pigmentary disorders. Many noninvasive instruments have been developed for this purpose, including the Dermacatch and VISIA devices. Huang et al sought to assess a new and advanced skin imaging system (OBSERV 520x) in assessing pigmentation and erythema and compare it with other similar devices (Dermacatch and VISIA) currently available to clinicians and researchers.⁵

Comparing Skin Imaging Systems

The OBSERV 520x is a newly developed advanced skin imaging system that can synthesize daylight, cross-polarized light, parallel-polarized light, Wood lamp light, and true UV light with the goal of analyzing diverse facial skin features including texture, pigmentation, vascularity, rhytids, volume, and contour. The novel device also features a patented face positioning system, using visual feedback technology to improve overall positioning. Images are captured from 5 angles and analyzed holistically and in specific areas through parameters that assess pigmentation (B1, B2) and erythema (R1, R2).

The authors in this study recruited 60 participants who had been previously diagnosed with facial pigmentary or inflammatory conditions, which were evaluated and confirmed by 2 different certified dermatologists from the Chang Gung Memorial Hospital in Taiwan. Pigmentary diseases included melasma, freckles, lentigo, postinflammatory hyperpigmentation, and vitiligo; inflammatory/erythematous conditions included were rosacea, acne, and telangiectasias. Study participants were then evaluated by the OBSERV 520x, Dermacatch, and VISIA devices under controlled dark conditions in the same room. For regional analysis, 2 dermatologists were tasked with identifying the most severe spot within the lesional area. Two certified dermatologists also evaluated the skin of each study participant who presented with pigmentary alteration by using the MASI score, which was calculated by averaging the scores.

Key Findings

The authors found that the OBSERV 520x demonstrated consistency with the Dermacatch and VISIA devices when assessing pigmentation and erythema through the calculation of correlation coefficients. Correlations of visual grading and pigmentation-related parameters were also calculated. Furthermore, the OBSERV 520x demonstrated a significant correlation with the MASI score and showed a stronger aptitude for hyperpigmentation assessment vs the VISIA device. This is supported by the fact that the OBSERV 520x showed a stronger correlation for B2 (compared with B1) when compared with the 2 other devices, even when significance was not observed. The OBSERV 520x device was also able to use the B1 and R1 parameters in measurements of ratios of diseased to normal skin. Given this capability, the MASI score can be quantitatively interpreted based on the analysis of the B1 and B2 parameters of the severity and involvement ratio of pigmentation on the entire face.

Other advantages of the OBSERV 520x that the authors demonstrated in their research included the fact that this new system can perform a comprehensive analysis that encompasses both full face and selected areas within the same image set, obviating the need for 2 separate images. The OBSERV 520x was also able to evaluate depigmentation through the incorporation of a Wood lamp source, which the 2 other systems do not have. The OBSERV 520x is also faster in that it can record 8 high-resolution pictures through 5 set angles in 10 seconds, which is an improvement compared with the other 2 devices. This could be an advantage when conducting large-scale population studies in clinical research and clinical trials.

Future Research Opportunities

Although further studies on this novel device for assessing erythema and facial pigmentation are needed, the authors of this study were able to validate the accuracy of the new OBSERV 520x device. Compared with the 2 previous systems (Dermacatch and VISIA), this new device demonstrated a higher correlation with visual scores, which were evaluated by dermatologists, and demonstrated improvements in analysis. Devices such as the OBSERV 520x device are important when conducting research on medications that seek to improve pigmentary issues or erythema, as subtle changes or improvements may not be appreciated by human observers.

Evaluation by a trained dermatologist remains one of the gold standards for assessing treatment response for certain medications, but objective measurements by devices such as the OBSERV 520x are increasingly being recognized as critical to the development and success of medications used to treat pigmentary and inflammatory disorders. Clinicians studying and researching pigmentary conditions such as melasma may find this novel device beneficial in their clinical and research endeavors, and this device may become the standard of care as the technology becomes cheaper and more readily available in the future.

Nicholas Brownstone, MD, is the chief dermatology resident at Temple University Hospital in Philadelphia, Pennsylvania.

References

1. Yoo J. Differential diagnosis and management of hyperpigmentation. Clin Exp Dermatol. 2022;47(2):251-258. doi:10.1111/ced.14747.
2. The scoring aid: MASI and modified MASI. Plastic Surgery Key. August 20, 2017. Accessed August 6, 2024. https://plasticsurgerykey.com/the-scoring-aid-masi-and-modified-masi/
3. Pandya AG, Hynan LS, Bhore R, et al. Reliability assessment and validation of the Melasma Area and Severity Index (MASI) and a new modified MASI scoring method. J Am Acad Dermatol. 2011;64(1):78-83.e2. doi:10.1016/j.jaad.2009.10.051
4. Prendergast PM, Shiffman MA. Aesthetic Medicine: Art and Techniques. Springer; 2012. Accessed August 8, 2024. https://www.researchgate.net/publication/297369903_Aesthetic_Medicine_Art_and_Techniques
5. Huang YW, Arkesteijn W, Lai YJ, Ng CY. A comparative study of an advanced skin imaging system in diagnosing facial pigmentary and inflammatory conditions. Sci Rep. 2024;14(1):14673. doi:10.1038/s41598-024-63274-7