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Updated: Aug 14, 2026

Studying Chronic Exposure of Mice to Ultraviolet B Radiation
Published on: August 19, 2025
[Clinical aspects and pathogenesis of UV-induced pigmentary disorders]
Jean-Paul Ortonne1, Thomas Schwarz
1Hautklinik, Hôpital L'Archet 2, Nizza, Frankreich.
Abstract:
Solar and ultraviolet (UV) radiation, respectively, are the strongest stimuli for the induction of pigmentation in human skin. UV radiation induces pigmentation by exerting direct and indirect effects on melanocytes. Melanogenesis is a very complex process whose molecular mechanisms are not yet completely understood. Acute UV exposure induces the non-protective immediate pigment darkening as well as delayed tanning which exerts photoprotective effects. Chronic UV exposure causes permanent pigmentary changes by inducing solar lentigines and pigmented actinic keratoses as well hypopigmentated areas. Artificial UV irradiation (UVA, PUVA) can also induce pigmentary disorders, including lentigines. Since the therapeutic options for UV-induced pigmentary changes are limited consequent protection as a prophylactic measure is recommended.
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