Fitzpatrick Skin Phototype Is Independently Associated with Differential Short-Term Cutaneous Reactivity Following Standardized Topical Provocation in Humans

Fitzpatrick skin phototype is independently associated with early and short-term cutaneous reactivity following standardized topical provocation in humans. Lighter phototypes (I-II) demonstrate increased susceptibility to transient inflammatory responses, whereas phototype III shows markedly reduced reactivity. These findings support the role of skin phototype as a constitutional modifier of short-term cutaneous responses and highlight the importance of considering pigmentation-related phenotypes in the design and interpretation of dermatological testing, cosmetic tolerability studies, and safety assessments of topical formulations.