Ficus carica L photodermatitis: a report of five cases with histopathologic study and review of the literature.

Phytophotodermatitis is a condition caused by contamination of the skin with phototoxic plant substances, followed by exposure to ultraviolet rays. Ficus carica L 1753, belonging to the Moraceae family, can be responsible for acute photodermatitis. We present five cases of photodermatitis caused by contact with Ficus carica L and subsequent exposure to sunlight. A histopathologic study and review of the literature are included.

Use of alternative test methods in a tiered testing approach to address photoirritation potential of fragrance materials.

The safety assessment of fragrance materials for photoirritation utilized by The Research Institute for Fragrance Materials has recently been modified and is described in detail. Materials demonstrating significant absorbance in the ultraviolet and visible light (UV/VIS) range (290-700 nm) may present a concern for photoirritation and require further investigation. If there are no photoirritation data or data are insufficient, then data on read-across materials are considered before a tiered approach for testing begins. The hazard-based 3T3-Neutral Red Uptake (NRU) Phototoxicity Test (OECD TG 432) is used as a first-tier assay; if it predicts photoirritation, it is followed by the reconstructed human epidermis (RhE) phototoxicity assay (OECD TG 498). The RhE phototoxicity assay is used to determine a No Observed Effect Level (NOEL) for photoirritation that is used in a confirmatory human photoirritation test. Data are presented on 108 fragrance materials exhibiting significant UV/VIS absorbance and evaluated in the 3T3-NRU Phototoxicity Assay. Twenty-one materials were predicted to be phototoxic; twenty were evaluated in the RhE Phototoxicity Assay to establish a NOEL. Fourteen materials were then evaluated in a confirmatory human phototoxicity test. The tiered testing approach presented represents a scientifically pragmatic method to minimize the likelihood of photoirritation from fragrance materials.

A cross-industry survey on photosafety evaluation of pharmaceuticals after implementation of ICH S10.

A cross-industry survey was conducted by EFPIA/IQ DruSafe in 2018 to provide information on photosafety evaluation of pharmaceuticals after implementation of ICH S10. This survey focused on the strategy utilized for photosafety risk assessment, the design of nonclinical (in vitro and in vivo) and clinical evaluations, the use of exposure margins in risk assessment, and regulatory interactions. The survey results indicated that a staged approach for phototoxicity assessment has been widely accepted by regulatory authorities globally. The OECD-based 3T3 NRU Phototoxicity Test is the most frequently used in vitro approach. Modifications to this assay suggested by ICH S10 are commonly applied. For in-vitro-positives, substantial margins from in vitro IC50 values under irradiation to Cmax (clinical) have enabled further development without the need for additional photosafety data. In vivo phototoxicity studies typically involve dosing rodents and exposing skin and eyes to simulated sunlight, and subsequently evaluating at least the skin for erythema and edema. However, no formal guidelines exist and protocols are less standardized across companies. A margin-of-safety approach (based on Cmax at NOAEL) has been successfully applied to support clinical development. Experience with dedicated clinical phototoxicity studies was limited, perhaps due to effective de-risking approaches employed based on ICH S10.

Phototoxic versus photoprotective effects of tattoo pigments in reconstructed human skin models: In vitro phototoxicity testing of tattoo pigments: 3D versus 2D.

The increasing number of tattooed persons urges the development of reliable test systems to assess tattoo associated risks. The alarming prevalence of 60 % phototoxic reactions in tattoos ask for a more comprehensive investigation of phototoxic reactions in tattooed skin. Here, we aimed to compare the cellular responses of human skin cells to ultraviolet (UV)A and UVB irradiation in doses of short to intermitted sun exposure (3-48 J/cm² and 0.05-5 J/cm², respectively) in the presence of tattoo pigments. Therefore, we used fibroblast monolayer culture (2D), our recently developed three dimensional full-thickness skin model with dermal-located tattoo pigments (TatSFT) and its dermal equivalents (TatSDE) that lack keratinocytes. We tested the most frequently used tattoo pigments carbon black, titanium dioxide (TiO2) anatase and rutile as well as Pigment Orange (P.O.)13 in ranges from 0.067 to 2.7 ng/cell in 2D. For TatSDE and TatSFT, concentrations were 1.3 ng/cell for TiO2, 0.67 ng/cell for P.O.13 and 0.067 ng/cell for carbon black. We assessed cell viability and cytokine release in all systems, and cyclobutane pyrimidine dimer (CPD) formation in TatSFT. Phototoxicity of tattoo pigments was exclusively observed in 2D, where especially TiO2 anatase induced phototoxic effects in all concentrations (0.067-2.7 ng/cell). In contrast, fibroblasts were protected from UV irradiation in TatSDE by TiO2 and carbon black. Neither toxic nor protective effects were recorded in TatSFT. P.O.13 showed altered cytokine secretion in 2D (0.067-1.3 ng/cell) and TatSDE, despite the absence of significant effects on viability in all systems. All pigments reduced the number of CPDs in TatSFT compared to the pigment-free controls. In conclusion, our study shows that within a 3D arrangement, intradermal tattoo pigments may act photoprotective despite intrinsic phototoxic properties in 2D. Thus, dermal 3D equivalents should be considered to evaluate acute tattoo pigment toxicology.

Inflammatory involvement into phototoxic reaction in erythropoietic protoporphyria (EPP) patients.

Phototoxic reaction is a known feature of EPP at least in part triggered by the oxidative status, complement system activation, and mast cell response. The aim of this study was to verify some aspects involved in phototoxic reaction during a season. The complement system was evaluated by C3 assay, alternative pathway by factor-B, and classical pathway by C1q; oxidative status was tested with malondialdehyde (MDA) and mast cell by IL-10 assay. The serum samples were collected in winter and summer from 19 EPP patients and 13 controls. The reaction to sun exposure within each group was monitored without any invasive treatment. In summer, C3 and factor B were higher in patients than in controls (p = 0.002 and < 0.0001 respectively), while no change was detected for C1q. The oxidative stress was increased in summer in comparison with the control group (p = 0.04), and IL-10 an assay was normal in both seasons. The correlation between the C3 and factor-B in summer was significant. This study shows that the phototoxic reaction is not limited to the dermis but can also exert a systemic response, which could affect the general health of a patient. The knowledge of the pathophysiology of phototoxic reaction is essential for identifying new disease markers useful for improving clinical studies of known and future drugs.

Photochemical and Pharmacokinetic Characterization of Orally Administered Chemicals to Evaluate Phototoxic Risk.

This study aimed to verify the applicability of a proposed photosafety screening system based on a reactive oxygen species (ROS) assay and a cassette-dosing pharmacokinetic (PK) study to chemicals with wide structural diversity. The orally taken chemicals, erythromycin, gatifloxacin, 8-methoxypsoralen (MOP), pirfenidone (PFD), trifluoperazine (TFP), and voriconazole (VRZ), were selected as test compounds. The ROS assay was conducted to evaluate their photoreactivity, and all test compounds excluding erythromycin generated significant ROS under simulated sunlight exposure. According to the ROS data, TFP had potent photoreactivity, and the photoreactivity of 4 other compounds was judged to be moderate. Regarding the oral cassette-dosing PK test in rats, the skin deposition of MOP, PFD, and VRZ was relatively high, and gatifloxacin and TFP exhibited moderate skin deposition properties. Based on the ROS and PK data of test compounds, PFD and TFP were judged to be potent phototoxic compounds, and MOP and VRZ were deduced to have phototoxic risk. The predicted phototoxic risk of test compounds by proposed screening was mostly in agreement with observed in vivo phototoxicity in the rat skin. The proposed screening system could provide reliable photosafety information on orally administered compounds with wide structural diversity.

Photodermatoses in skin of colour.

Photodermatoses represent a heterogeneous collection of disorders unified by the characteristic of being provoked through exposure to ultraviolet radiation. Generally, these conditions are classified into the following categories: immunologically mediated photodermatoses, chemical- and drug-induced photosensitivity, photoaggravated dermatoses and photosensitivity associated with defective DNA repair mechanisms or chromosomal instabilities. The list of photodermatoses is extensive, and each individual photodermatosis is understood to a different extent. Regardless, there exists a paucity of information with regards to the clinical presentation among those with skin of colour. With ever-changing global demographics, recognition of photosensitive disorders in a diverse population is essential for accurate diagnoses and therapeutic guidance. The scope of this article seeks to review the epidemiology and clinical variability in presentation of such photodermatoses in patients with skin of colour.

The abdominal skin of female Sprague-Dawley rats is more sensitive than the back skin to drug-induced phototoxicity.

In vivo phototoxicity studies are important to predict drug-induced phototoxicity in humans; however, a standard methodology has not established. To determine differences in sensitivity to drug-induced phototoxicity among various skin sites, we evaluated phototoxic reactions in the back and abdominal skin of female Sprague-Dawley rats orally dosed with phototoxic drugs (pirfenidone, 8-methoxysoraren, doxycycline, and lomefloxacin) or a non-phototoxic drug (gatifloxacin) followed by solar-simulated light irradiation comprising 18J/cm2 ultraviolet A. Tissue reactions were evaluated by macroscopic and microscopic examination and immunohistochemistry for γ-H2AX, and tissue concentrations of pirfenidone, doxycycline, and lomefloxacin were measured by tandem mass spectrometry. In addition, the thicknesses of the skin layers at both sites were measured in drug-naïve rats. The abdominal skin showed more severe reactions to all phototoxic drugs than the back skin, whereas the minimal erythema dose in drug-naïve rats and skin concentrations of each drug were comparable between the sites. Furthermore, histopathological lesions and γ-H2AX-positive cells in the abdominal skin were detected in deeper layers than in the back skin. The stratum corneum and dermis in the abdominal skin were significantly thinner than in the back skin, indicating a difference in the depth of light penetration and potentially contributing to the site differences observed in sensitivity to phototoxicity. Gatifloxacin did not induce any phototoxic reactions at either site. In conclusion, the abdominal skin is more sensitive to drug-induced phototoxicity than the back skin and may represent a preferable site for irradiation in this rat phototoxicity model.

Assessing phototoxicity in live fluorescence imaging.

Are the answers to biological questions obtained via live fluorescence microscopy substantially affected by phototoxicity? Although a single set of standards for assessing phototoxicity cannot exist owing to the breadth of samples and experimental questions associated with biological imaging, we need quantitative, practical assessments and reporting standards to ensure that imaging has a minimal impact on observed biological processes and sample health. Here we discuss the problem of phototoxicity in biology and suggest guidelines to improve its reporting and assessment.

In vitro assessment of skin sensitization, photosensitization and phototoxicity potential of commercial glyphosate-containing formulations.

This study evaluated the applicability of a modified Direct Peptide Reactivity Assay (DPRA) (OECD N° 442C, 2015) through the 10-fold reduction of reaction volume (micro-DPRA, mDPRA) for skin sensitization evaluation of six commercial glyphosate-containing formulations. In addition, another modification of DPRA was proposed by adding a UVA (5J/cm2) irradiation step, namely photo-mDPRA, to better characterize (photo)sensitizer materials. The phototoxicity profile of pesticides was also evaluated using the 3T3 Neutral Red Uptake Phototoxicity Test (3T3-NRU-PT) (OECD N° 432, 2004). The mDPRA could represent an environmentally acceptable test approach, since it reduces costs and organic waste. Peptide depletion was greater in photo-mDPRA and changed the reactivity class of each test material, in comparison to mDPRA. Thus, the association of mDPRA with photo-mDPRA was better for correctly characterizing human (photo)sensitizer substances and pesticides. In general, cysteine depletion was greater than that of lysine for all materials tested in both mDPRA and photo-mDPRA. Furthermore, while 3T3-NRU-PT is unable to predict (photo)sensitizers, it was capable of correctly identifying the phototoxic potential of the tested agrochemical formulations. In conclusion, mDPRA plus photo-mDPRA and 3T3-NRU-PT seem to be preliminary non-animal test batteries for skin (photo)sensitization/phototoxicity assessment of chemicals, agrochemical formulations and their ingredients.

Histological Features of Methylene Blue-Induced Phototoxicity Administered in the Context of Parathyroid Surgery.

Methylene blue is a chromophore dye known for its photosensitizing properties. It is also administered intravenously as a tracer in parathyroid surgery to identify abnormal glands. We describe 2 cases of acute methylene blue-induced phototoxicity in patients who underwent parathyroidectomy. Both patients developed an acute vesiculopustular inflammatory rash on the anterior neck corresponding to the site exposed intraoperatively to overhanging surgical lights. One of the patients also developed a bulla on her finger at the site of attachment of the oxygen probe. Biopsies were taken from both patients at different time points. The histological findings included destruction of sebaceous glands and deposition of diastase-periodic acid-Schiff-positive hyaline material around dermal blood vessels. These features are similar to those seen in skin treated with photodynamic therapy and systemic photosensitivity disorders such as the porphyrias. The wavelengths of light emitted by the surgical lights and oxygen probe overlap with the absorption spectrum of methylene blue. This resulted in excitation of the systemically administered methylene blue at exposed sites, with resultant local tissue damage and a phototoxic reaction.

Lemons in the Arizona Sunshine: The Effects of Furocoumarins Leading to Phytophotodermatitis and Burn-like Injuries.

INTRODUCTION: Phytophototoxic dermatitis is a strong phototoxic reaction to ultraviolet A (UV-A) radiation exposure after cutaneous contact with citrus fruit containing furocoumarins, leading to skin injury. At the Arizona Burn Center (Phoenix, AZ), the majority of these injuries are managed in the outpatient setting. CASE REPORT: The authors present a pediatric admission for burn-like injuries following prolonged cutaneous exposure to lemons while playing in the Arizona sunshine. A 7-year-old girl playing in her backyard squeezed lemon juice onto her skin while in the hot Arizona sunshine; within 24 hours, the child experienced pain, erythema, and blistering to multiple areas of her skin. She was admitted to the authors' burn center for wound care and pain control. She had scattered first-degree and second-degree burn-like lesions to her face, neck, and chest as well as bilateral forearms, hands, lower extremities, and feet. After blister debridement, appropriate dressing care, and pain medication, the patient was discharged home after 4 days of hospitalization with appropriate clinical follow-up. CONCLUSIONS: Burn-like lesions caused by furocoumarins after cutaneous absorption and UV-A exposure are known clinical entities in Arizona. The sequential progression from erythema to blisters equivalent to second-degree burn-like lesions to cutaneous hyperpigmentation is a well-described clinical triad. Meticulous wound care and pain control for the treatment of these burn-like lesions are essential as is the need for the wound care specialist to be well versed on this topic to quickly identify the etiology of the injury, thereby avoiding misdiagnosing the patient with nonaccidental traumatic injuries.

Interplay Between Membrane Lipid Peroxidation and Photoproduct Formation in the Ultraviolet A-Induced Phototoxicity of Vemurafenib in Skin Keratinocytes.

According to some authors, the phototoxic response to ultraviolet A (UVA) of patients treated with vemurafenib (VB) may involve VB metabolites. However, the production of singlet oxygen and free radicals and photoproduct formation upon UVA light absorption by the lipophilic VB have been demonstrated. This work is aimed at determining the contribution of reactive oxygen species (ROS), lipid photoperoxidation, and VB photochemistry in the UVA-induced photocytotoxicity in NCTC 2544 keratinocytes. The potent membrane lipid peroxidation effectiveness of VB-photosensitization has been proved by the observation of an effective photohemolysis accompanied by thiobarbituric reactive substances (TBARS) formation in 2% red blood cell (RBC) suspensions. Photohemolysis is inhibited by human serum albumin (HSA) that binds VB and by the antioxidants 2,6-di-tert-butyl-4-methylphenol and Trolox. These data on RBC suggest that VB is readily incorporated in cell membranes and provide clues for understanding the UVA-induced VB-photosensitization of keratinocytes. In keratinocytes, ROS and TBARS formation with 10 µM VB is inhibited by approximately 40% and 50% by 30 µM Trolox and 50 µM vitamin E, respectively, but the light dose-dependent cell survival is unaffected. Whereas cell photokilling depends on the VB concentration, much smaller changes in the lethal doses (LD) than theoretically expected are observed for 25% or 50% cell photokilling when changing absorbed UVA doses and irradiation wavelengths. The lack of antioxidant effect on cell survival and the unexpectedly small LD dependence on absorbed UVA light doses and on irradiation wavelengths strongly suggest that, instead of metabolites, membrane photosensitization and photoproduct formation contribute to the cell photocytotoxicity.

Cutaneous Phototoxicity: Clinical Observations versus Histopathological Findings.

Determination of test material-induced cutaneous phototoxicity for risk assessment has traditionally been based on visually observed skin reactions such as erythema, edema, and flaking. Because of its role in determining a toxic effect, the use of histopathological evaluation in this determination arises from time to time. However, there is little published information regarding the time course and types of histopathologic changes in the skin after test material-induced phototoxic insult nor any regulatory requirement or precedent for its use. This work evaluated both the visual and histopathological time course of the phototoxic response of the skin of the Long-Evans rat after oral administration of the phototoxins sparfloxacin and 8-methoxypsoralen (MOP) followed by a single exposure to solar-simulated ultraviolet radiation. Both sparfloxacin and 8-MOP elicited visual cutaneous reactions and microscopic changes consistent with a phototoxic response. The visually observed cutaneous time course and elicited histopathologic changes differed in response and extent for each phototoxin, but in both instances, microscopic evaluation did not alter the determination of a phototoxic response based on visual observations. These results indicate that, though histopathologic evaluations may have value for investigating mechanisms of phototoxicity, histopathologic evaluation of the skin is not warranted for determination of phototoxic potential in safety assessment intended for regulatory submission.

Pirfenidone-induced photoleukomelanoderma in a patient with idiopathic pulmonary fibrosis.

This is believed to be the first report of pirfenidone-induced photoleukomelanoderma. We discuss the male predominance of photosensitivity induced by pirfenidone. Both ultraviolet (UV)-A and UV-B seemed to be included within the action spectrum of this disorder. Although pirfenidone is a key drug for the treatment of idiopathic pulmonary fibrosis, clinicians should be aware of the high prevalence of photosensitivity and perform sufficient patient education for comprehensive photoprotection before prescription.

An unusual rash for Royal: a case series.

Eight patients, whilst on exercise in Albania, presented with a blistering, erythematous and itchy rash, consistent with caustic burns, after living in dense vegetation for a few days. All patients were found to have been living and operating under fig trees and had come into contact with the sap of Ficus carica, which on exposure to ultraviolet A (UVA) radiation, can cause a process of phytophotodermatitis leading to a blistering rash.