Nalini Kaul

Princeton Consumer Research, Canada

Title: Assessing product efficacy and safety in clinical trial design involving sensitive skin subjects with facial erythema


Sensitive skin is an important growing field in dermatology and is being reported from all over the world with more than 80% of the global adult population self-declaring it ().  Sensitive skin is a result of skin’s hyper-reactivity to environmental, physiological or lifestyle factors which affects all skin types, body locations, especially the face. This syndrome which continues to provoke tremendous interest is defined by the occurrence of unpleasant sensations (stinging, tingling, tightness, burning) primarily erythema, in response to stimuli that should not normally provoke. Skin erythema relates to underlying skin color and relative vascular burden and visibility through the skin. Although facial skin redness is not life threatening, it affects self-esteem and leads to isolation. While pathophysiology of sensitive skin remains to be fully understood, an impaired barrier and inflammatory reactions are thought to play key roles along with thin or dehydrated SC, increased sweating, increased epidermal innervations, and decreased lipids. TRPVI has been identified in playing an important role in sensitive skin.  With abundant availability, affordability, comes the incorporation of various cosmetic and toiletries in today’s lifestyle, triggering sensitive skin, with reporting being at an all-time high.  Our objective was to investigate facial redness associated with sensitive skin and assess efficacy, safety and tolerability of products using multiple approaches including visual expert grading, non-invasive biophysical measurements, digital imaging and self-perception questionnaires.
Test Article and Methods: 35 subjects with facial redness of Fitzpatrick types 1-3 who gave informed consent and met the eligibility criteria were enrolled in the clinical trial. The test article for the study was used once daily. Visual skin grading was carried out by an expert grader. Colorimetric analysis was carried out for a* parameter being the most relevant to assess redness of skin. TEWL was used for studying barrier disruption, and Mexameter determining the erythema index was also used. As these instruments cover only a small area of the face and are not representative of the entire face, it necessitated the use of an imaging technique -VISIA-CR by which the redness of the entire face could be assessed without making skin contact. Non-contact perfusion measurements of skin blood flow a laser doppler was used in the study.
Results: Visual and instrument readings showed statistically significant improvement at various time points in the skin parameters assessed, especially facial redness after test article use when compared to baseline. VISIA-CR images proved to be a useful in objectively capturing skin redness. In addition, the laser doppler measurement of blood flow and the actual erythema gave a more detailed information about the erythema than visuals or biophysical instruments alone.
Conclusion: As more people, especially women, are complaining about skin sensitivity primarily facial redness, to lessen their grief and help them in making the right selection from the plethora of cosmetic and toiletry products being offered, the claim for relief of redness and sensitive skin needs to be scientifically tested, proven and validated. The cosmetic products tested in our clinical trial proved to be efficacious, safe and well tolerated by subjects with sensitive skin. Additionally, our study provides support for the use of various subjective and objective techniques employing non-invasive instruments for evaluating products for facial redness and sensitive skin, thus helping in their development.  


Dr Nalini Kaul completed her PhD. from PGIME&R Chandigarh, India. Post- doctoral training was at St Boniface General Hospital Winnipeg Canada and at the University of Southern California, USA. Soon after she took a Senior Scientist position at the University of Dallas, Texas. Following her return to Canada in 2000 she worked as Technical Director on Clinical trials with a reputed CRO, moved on to hold a joint appointment as Sr. Director of Regulatory Affairs and Director of Clinical trials with another company. At present she is Vice President of Technical services at a well reputed CRO serving North American and the UK. She has published about 40 papers in national and international journals, has several book chapters to her credit and also has presented widely at conferences both nationally and internationally. Her area of expertise involves clinical trials involving all personal care products, OTC products and dietary supplements. Besides providing technical expertise and regulatory to clients for study designs she also serves as Principal Investigator.