%0 Journal Article
%T Protoporphyrin IX-induced phototoxicity: Mechanisms and therapeutics.
%A Hussain Z
%A Qi Q
%A Zhu J
%A Anderson KE
%A Ma X
%J Pharmacol Ther
%V 248
%N 0
%D 2023 08 29
%M 37392940
%F 13.4
%R 10.1016/j.pharmthera.2023.108487
%X Protoporphyrin IX (PPIX) is an intermediate in the heme biosynthesis pathway. Abnormal accumulation of PPIX due to certain pathological conditions such as erythropoietic protoporphyria and X-linked protoporphyria causes painful phototoxic reactions of the skin, which can significantly impact daily life. Endothelial cells in the skin have been proposed as the primary target for PPIX-induced phototoxicity through light-triggered generation of reactive oxygen species. Current approaches for the management of PPIX-induced phototoxicity include opaque clothing, sunscreens, phototherapy, blood therapy, antioxidants, bone marrow transplantation, and drugs that increase skin pigmentation. In this review, we discuss the present understanding of PPIX-induced phototoxicity including PPIX production and disposition, conditions that lead to PPIX accumulation, symptoms and individual differences, mechanisms, and therapeutics.