The Fitzpatrick scale is a numerical classification schema for human skin color developed by American dermatologist Thomas B. Fitzpatrick in 1975. The scale is used to estimate the response of different types of skin to ultraviolet (UV) light and to determine a patient's risk of burning or tanning when exposed to UV light. The Fitzpatrick scale remains a recognized tool for dermatological research into human skin pigmentation.The scale classifies skin into six categories based on skin color and how it responds to the sun. The following are the six categories of the Fitzpatrick scale in relation to the 36 categories of the older von Luschan scale (in parenthesis)  Type I (scores 0–6) always burns, never tans (palest; freckles) Type II (scores 7–13) usually burns, tans minimally Type III (scores 14–20) sometimes mild burn, tans uniformly Type IV (scores 21–27) burns minimally, always tans well (moderate brown) Type V (scores 28–34) very rarely burns, tans very easily (dark brown) Type VI (scores 35–36) never burns (deeply pigmented dark brown to darkest brown) The Fitzpatrick scale has some limitations, including that the original version of the scale did not contain classifications for darker skin tones. In its first version, the scale only included types I to IV and was considered “Anglo-Irish centric.” Types V and VI were added later.