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Published in Ken Addley, MCQs, MEQs and OSPEs in Occupational Medicine, 2023
Confirmation of photoallergy is by photo patch testing. The pathophysiology is similar to allergic contact dermatitis. Photoallergic skin reactions are less common than phototoxic reactions and their appearance is usually sudden. They may appear in non–sun-exposed areas.
Acyclovir
Published in Anton C. de Groot, Monographs in Contact Allergy, 2021
A patient with suspected photosensitivity to acyclovir cream had a positive photopatch test to the cream, but not to any of its ingredients. A diagnosis of compound photoallergy was made (10). Possibly, a similar case has been observed in France (11).
Cutaneous Photosensitization
Published in David W. Hobson, Dermal and Ocular Toxicology, 2020
Photoallergy is an acquired immunologically mediated reaction to a chemical initiated by the formation of photoproducts. The occurrence of a photoallergic response to a chemical is sporadic and highly dependent upon the specific immune reactivity of the host. Photoallergic responses are thought to be cell-mediated hypersensitivity reactions involving two distinct mechanisms. In the first reaction type, light initiates the conversion of the hapten (synonymous with photosensitizer) to a complete allergen. Animal studies suggest that the photoreactive chemical in the skin absorbs light and is converted to a photoproduct that subsequently binds to tissue proteins producing a complete antigen.12–14
Photocatalytic activity of nanoparticles: the development of the standardized measurement for physiological conditions
Published in Nanotoxicology, 2022
Vytas Reipa, Nam Wong Song, Minjeong Kwak, Min Beom Heo, Tae Geol Lee, Paul Westerhoff, Yuqiang Bi, Blaza Toman, Vincent A. Hackley, Haruhisa Kato, Yosuke Tabei, Kanokwan Nontapot, Yonghyun Choi, Jonghoon Choi
A broad range of nanomaterials, currently used as photocatalysts, UV light blockers in sunscreens, display materials as well as in nanotherapeutics are produced in large quantities (TiO2, ZnO, WO3, CeO2, quantum dots, etc.) and can produce reactive oxygen species (ROS) under light exposure. Phototoxicity can be further categorized as photo-irritation, photo-allergy and photo-genotoxicity. Assessment of these effects require dedicated in vitro and in vivo assays developed for soluble chemicals (Ceridono et al., 2012, Maurer 1987), and photocatalytic activity (PCA) has been identified by the Organization for Economic Cooperation and Development (OECD) as one of the seventeen physicochemical parameters of MNMs relevant to environmental safety and human health (Yin et al. 2014).
Evaluating FMX-101 as a promising therapeutic for the treatment of acne
Published in Expert Opinion on Pharmacotherapy, 2020
Isabel Cristina Valente Duarte de Sousa
Results of four separate, single-center, randomized, vehicle-controlled phase I trials that evaluated the potential of FMX-101 4% foam for phototoxicity, photoallergy, skin sensitization and cumulative skin irritation in healthy individuals were published earlier this year. A total of 363 subjects were included across the four studies (32 in the phototoxicity study, 56 in the photoallergy study, 233 in the skin sensitization study and 42 in the cumulative skin irritation study). The studies found no evidence of phototoxicity, photoallergy, skin sensitization or cumulative skin irritation with FMX-101 4% foam [58].
Prospects of topical protection from ultraviolet radiation exposure: a critical review on the juxtaposition of the benefits and risks involved with the use of chemoprotective agents
Published in Journal of Dermatological Treatment, 2018
Nilutpal Sharma Bora, Bhaskar Mazumder, Pronobesh Chattopadhyay
Stinging and burning sensations are some of the common complaints associated with the application of sunscreens although rare but evident cases of allergic contact dermatitis are also observed (81,82). PABA and oxybenzone are the few ingredients used today which are considered as photoallergens. Other ingredients which have fewer reported skin hypersensitivity reactions are octinoxate, avobenzone, padimate O, and sulisobenzone (81). Individuals already associated with eczema and photodermatoses may be predisposed to developing photoallergy and should be properly consulted with prior to prescription (64,83).