A case of photoallergic dermatitis caused by pirfenidone

Abstract

The most important side effect of pirfenidone is photosensitivity caused by the phototoxic effect. Here, we report a rare case of photosensitive drug eruption due to a photoallergic reaction, which was proven through a photopatch test and DLST.

Pirfenidone-Induced Photosensitive Dermatitis: A Rare Side Effect

“…Reports of photosensitivity with the administration of pirfenidone vs placebo were 12% vs 2% [5]. In another study, photosensitivity reactions were reported in 24% of patients receiving high doses of the drug [4] while according to a study by Kuskabe et al (2018) the incidence of photosensitivity post pirfenidone was 51.7% in its clinical trial stage [6]. Photosensitivity as a reaction to pirfenidone remains one of the major reasons for the discontinuation or decreased dosage of the drug.…”

“…The reported cases with serious photosensitizing drug eruptions caused by pirfenidone are due to its phototoxic effect and its ability to absorb UVA and UVB. The absorption of UV radiation by pirfenidone present in the skin leads to lipid peroxidation and reactive oxygen species causing skin lesions [7], the clinical features of which resemble sunburn [6]. These events show a tendency to occur early in the treatment and settle over time [5].…”

Severe Photosensitivity Reaction After Pirfenidone Use

“…While there have been multiple reported cases of pirfenidone-induced phototoxic effect, the mechanism of phototoxicity remains unclear [6][7][8]. A study by Seto et al discusses in vitro evidence of phototoxicity via generation of reactive oxygen species (ROS) via peroxidation of photodynamic lipids and cleavage of DNA due to exposure to sunlight [9].…”

“…Dose reductions have also been reported to avoid these side effects [ 1 ]. It has been recommended to counsel patients on wearing sun-protective clothing and SPF to prevent photosensitivity reactions [ 1 , 6 ]. In our patient's case, his symptoms started a few months after the initiation of therapy.…”

Pirfenidone‐induced phototoxic reaction

“…Cutaneous AE include photosensitivity and unspecified rash. Recently, it has been described that pirfenidone can induce both phototoxic 2,3 and photoallergic reactions 2,4 . Here we present a patient with a phototoxic reaction induced by pirfenidone and a review of the literature.…”