The Fitzpatrick Scale describes skin partly by how it reacts to sun exposure: how readily it burns, how readily it tans. It is a shorthand clinicians use when talking about energy-based treatment, because more melanin in the skin means more competition for the light being delivered. That affects which technology makes sense and how it is set.
It is only a starting point, though. Two people with the same Fitzpatrick type can have very different pigmentation, very different histories with the sun, and very different concerns. Kerri looks at the skin in front of her before she looks at the device.
She treats a wide range of complexions, including Asian, Black/African-American, and other patients with melanin-rich skin. In practice that means adjusting the technology and the settings to the person, and occasionally saying that a particular laser is not the right tool for a particular skin. When that happens, she will explain why and talk through the alternatives.