Photosensitivity diseases encompass a variety of conditions characterized by an abnormal skin response to ultraviolet (UV) radiation. Effective photoprotection is crucial in managing these conditions to prevent exacerbations and improve the quality of life for affected individuals.
Photosensitivity diseases, including polymorphous light eruption (PMLE), actinic prurigo, chronic actinic dermatitis, solar urticaria and porphyria, result from heightened sensitivity to sunlight radiation. Other photosensitivity disorders are caused by DNA repair defects, such as xeroderma pigmentosum, or others due to the lack of melanin, such as albinism. The cornerstone of managing these diseases is minimizing light exposure. Photoprotection strategies include the use of broad-spectrum sunscreens, protective clothing, and behavioural modifications to avoid peak sunlight hours. However, it is necessary to take into account the culprit wavelengths in every disease and in every patient to prescribe the most convenient sunscreen. In general, UVA and visible light are the most frequently involved, therefore sunscreens should contain filters and other active ingredients such as antioxidants or photoimmunoprotectors to provide better protection. Infrared radiation A (IRA) could also aggravate some of these photodermatosis. Additionally, systemic photoprotective agents, such as Polypodium leucotomos extract, have shown beneficial effects, especially in polymorphic light eruption.
Patient education is also important to have proper photoprotective behaviour using clothes, hats, sunglasses and using even protective screens and wearing dosimeters.
Regarding treatment, topical corticosteroids and calcineurin inhibitors are commonly prescribed to manage acute flare-ups, while systemic agents like antimalarials and immunosuppressants are reserved for severe cases. Solar urticaria could benefit of the use of omalizumab in recalcitrant cases. Furthermore, advances in phototherapy, including narrowband UVB therapy, have shown efficacy in desensitizing the skin and reducing the frequency of flare-ups in certain photosensitivity disorders. Genetic and molecular research is paving the way for targeted therapies that address the underlying pathophysiological mechanisms of these diseases.