The Aryl Hydrocarbon Receptor in Skin Exposome Biology: An Integrative Review

The physical exposome represents a major determinant of skin homeostasis, integrating environmental stimuli that influence cutaneous biological responses. Among the molecular mediators of these interactions, the Aryl hydrocarbon Receptor (AhR) has emerged as an important environmental sensor linking external physical factors to transcriptional and metabolic responses in the skin. This review examines how the physical exposome shapes skin biology through AhR-dependent pathways. Particular attention is given to ultraviolet (UV) and visible light, which provide a direct mechanistic connection between environmental radiation and AhR activation in cutaneous cells. The concept of photo-pollution, whereby UV radiation and chemical pollutants synergistically amplify damaging biological effects, is also discussed as a paradigm of combined exposome stressors. In addition, emerging but relatively understudied physical stimuli, including mechanical forces and electromagnetic radiation, are considered for their potential interactions with AhR signaling pathways. Together, these perspectives highlight the AhR as a central integrative node in the skin’s response to the physical exposome.