What factor does the Fitzpatrick skin typing system NOT consider?

The Fitzpatrick skin typing system is primarily designed to assess an individual's skin type based on their response to UV light exposure and their skin pigmentation. It classifies skin into six different types, taking into account how skin reacts to sun exposure in terms of tanning and burning.

The system evaluates skin pigmentation, which includes characteristics such as the natural color of the skin, and the type of response to UV light—whether a person burns easily, tans moderately, or has a higher ability to tan without burning.

However, the Fitzpatrick system does not consider the type of hair—such as whether it is dark, light, straight, or curly—since hair type does not directly impact the skin's reaction to UV light or its overall pigmentation classification. Altitude effects on skin are also not part of this classification system, as it focuses on inherent characteristics of the skin rather than external environmental factors. This focus on response to UV light and pigmentation makes the system a valuable tool in dermatology and aesthetic medicine for determining skin care and treatment plans.