Measurement Guide

1. What is skin sensitivity/redness?

For an average adult, skin covers about 22 square feet (2 square meters) of the body. Unlike other internal organs, skin is directly exposed to various irritants constantly, making it prone to sensitive reactions such as redness, itching, and pain. Although some people are born with sensitive skin, most people would not even know they have sensitive skin until they are exposed to certain irritants or allergens. Common causes of skin sensitivity includes:

• Sun exposure, extreme temperatures
• Irritants, such as chemicals, cosmetics, and certain clothing
• Allergens, i.e. substances the skin is allergic to
• Emotional stress
• Other underlying skin conditions or diseases, for example rosacea and kidney diseases

When skin is irritated, most likely it shows symptoms of redness, itching, and swelling, but there are also other signs such as skin scaling, flaky skin, crack and bleeding.

2. Chowis skin sensitivity grade

The following Chowis skin sensitivity grade has been co-developed by Chowis and dermatology experts. For each image, we detect skin sensitivity and provide a quantified score. An expert approved questionnaire is also included, as an option, in order to understand a customer's past diagnosis and treatment records and obtain a fuller profile of the customer's skin. Taking into account the questionnaire results, the final score for skin sensitivity is computed as the weighted average of the image score and questionnaire score. In case that questionnaire is skipped, only image detection result will be used. Based on the scale shown in Table 1, we grade skin sensitivity into clear, almost clear, mild, moderate and severe.