Measurement Guide

1. What is skin impurities/skin porphyrin?

Porphyrins are essential for the function of hemoglobin - a protein in your red blood cells that carries oxygen. However, buildup of porphyrins can affect nerve system and/or skin. In skin, the buildup of porphyrin mostly appear in hair follicles (pores) where large amounts of porphyrin-producing skin bacterium reside. Due to increased sensitivity to sunlight and inflammations caused by bacteria porphyrins, a person with excessive skin porphyrin may experience:

  • Sensitivity to the sun and sometimes artificial light, causing burning pain
  • Itching, or sudden painful redness and swelling
  • Fragile thin scalp skin with changes in skin color
  • Blisters on exposed scalp skin
  • Acnes and other inflammatory skin diseases

To assist diagnosis of impurities caused by skin porphyrin, a skin image needs to be taken under the UVL light using the Chowis Mobile Analyzer for Skin. Under the UVL light, impurities can be revealed as bright white, orange, and red spots. Our algorithm then evaluates the impurities in the image and provides the grading.

2. Chowis skin impurities grade

The following Chowis impurities grade has been co-developed by Chowis and dermatology experts. For each image, we detect impurities to provide a quantified score. Based on the scale shown in Table 1, we grade skin impurities into clear, almost clear, mild, moderate and severe.

Table 1. Skin impurities grade
GradeScaleDescription
Clear0 ~ 5Clear skin with little to no impurities
Almost Clear6 ~ 15Mild impurities resides in some pores
Mild16 ~ 48Moderate amount of impurities building up in many pores
Moderate49 ~ 80Severe buildup of impurities in large amount of pores
Severe81 ~ 99Very severe buildup of impurities in almost all pores
Table 2. Representative images of skin impurities grade
ClearImageImage
Almost ClearImageImage
MildImageImage
ModerateImageImage
SevereImageImage