Sap and Sun: A Case of Phytophotodermatitis.

We report a case of phytophotodermatitis caused by cow parsnip (Heracleum maximum) exposure affecting a hiker in Colorado. Phytophotodermatitis is a phototoxic skin reaction to UV-A rays after contact with photosensitizing plant substances that presents as a burning, painful rash, often with blisters. Treatment is supportive, including wound hygiene, analgesia, and anti-inflammatories. Avoiding offending plants, protecting the skin from sun, and immediate washing with soap and water after plant contact are the primary means of prevention. We have included a table and photos of plants found in the United States that can cause phytophotodermatitis. Medical providers should include phytophotodermatitis in the differential diagnosis of blistering rashes in patients who have been outdoors with possible exposure to offending plants.

[Current problems of polypharmacy in geriatric patients when taking drugs with a risk of photosensitivity.]

The article presents an overview of the current problems of polypharmacy in geriatric patients when taking drugs with a risk of photosensitivity. The article contains information about emerging adverse drug reactions, as well as methods for diagnosing, correcting and preventing phototoxic and photoallergic reactions in patients of older age groups. The main aspects of dermatological support in the system of long-term care for geriatric patients when taking drugs with a risk of photosensitivity are outlined. Clinical signs of senile xerosis and skin manifestations of adverse drug reactions were studied when taking drugs with the risk of photosensitization before and after the use of a photoprotector in elderly patients.

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.

Anticancer treatments and photosensitivity.

Drug-induced photosensitivity is associated with a wide range of anticancer treatments, including conventional chemotherapeutic agents, targeted anticancer therapies, and immune checkpoint inhibitors. These dermatologic adverse events can have a major impact on the well-being and quality of life of cancer patients, leading to dose modifications and interruption or discontinuation of anticancer treatments in severe cases. However, the heterogeneous nature of the photosensitive reactions induced by these agents, as well as the common concomitant use of other potentially photosensitizing drugs (antibiotics, voriconazole, nonsteroidal anti-inflammatory drugs, etc.), can make the diagnosis and, therefore the prevention, of these adverse events particularly challenging. The aim of this review is to describe the most characteristic forms of photosensitivity observed in patients being treated with anticancer treatments, including phototoxicity and photoallergy, and other potentially photo-induced manifestations such as UV recall, exaggerated sunburn reactions associated with treatment-related vitiligo, drug-induced cutaneous lupus erythematosus, and UV-induced hyperpigmentation. We also discuss the photosensitive reactions recently reported with new-generation targeted anticancer therapies and immune checkpoint inhibitors and highlight the importance of continued surveillance to identify photosensitizing agents, and of educating patients on the need for preventive UVA/UVB photoprotective measures.

Photosensitizing drug reactions.

Photosensitizing drug reactions are cutaneous eruptions that occur after exposure to ultraviolet radiation in patients using photosensitizing medications. The reactions can be broadly classified into phototoxic and photoallergic, with the former being much more common and well documented. There is an extensive list of photosensitizing medications, especially in the case of phototoxicity. The most common are amiodarone, chlorpromazine, doxycycline, hydrochlorothiazide, nalidixic acid, naproxen, piroxicam, tetracycline, thioridazine, vemurafenib, and voriconazole. Most of the medications implicated in photosensitivity share an action spectrum within the ultraviolet A range. Distinguishing between phototoxicity and photoallergy can be difficult, because some clinical overlap exists between the two disorders. It is often done based on pathogenesis, clinical presentation, and diagnosis. Management is similar for both types of reactions, with the gold standard being prevention. This review provides an overview of the photosensitizing drug reactions and highlights the similarities and differences between phototoxicity and photoallergy, as well as other photosensitizing drug reactions in the phototoxicity family including lichenoid reactions and pseudoporphyria.

[Establishment and International Harmonization of Photosafety Testing Strategy].

Considerable attention has been drawn to predict a photosafety hazard on new chemicals. A number of phototoxins tend to generate reactive oxygen species (ROS) via energy transfer mechanisms following UV/VIS excitation, including superoxide and singlet oxygen. Then, ROS assay has been designed to assess photoreactivity of pharmaceuticals, of which the principle is to monitor types I and II photochemical reactions of the test chemicals when exposed to simulated sunlight. This simple analytical test could be used to screen potential chemical scaffolds, leads, and candidate drugs to identify and/or select away from those having phototoxic potential. The validation study for the ROS assay has been being carried out by the Japan Pharmaceutical Manufacturers Association (JPMA), supervised by the Japanese Center for the Validation of Alternative Methods (JaCVAM). Although several false positives appeared, the ROS assay on 42 coded chemicals has provided no false negative predictions. The validation study tentatively indicates satisfactory outcomes in terms of transferability, intra- and inter-laboratory variability, and predictive capacity. Thus, a negative result in this ROS assay would indicate a very low probability of phototoxicity, whereas a positive result would be a flag for follow-up assessment. Upon international harmonization activities supported by several agencies and industrial groups, ROS assay was successfully adopted as International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) S10 guideline (2014) and Organisation for Economic Co-operation and Development (OECD) test guideline 495 (2019).

Margarita Burn: Recognition and Treatment of Phytophotodermatitis.

Phytophotodermatitis is a cutaneous reaction caused by direct contact with phototoxic agents and subsequent sunlight exposure. Furocoumarins and psoralens are 2 phototoxic agents that can cause this reaction, and these organic chemical compounds are found in many plant species consumed by humans. Following contact exposure to such foods and ultraviolet radiation exposure via direct sunlight, phytophotodermatitis can occur. Due to the etiology of these rashes relating closely to the outdoor consumption of margaritas, the rash may be known by patients as "margarita burn." There is a classically described sequence of rash progression: erythematous macules or patches, which later become vesicles and seem similar to second-degree burns, followed by an asymptomatic hyperpigmentation. This case presents a 26-year-old female diagnosed with phytophotodermatitis following use of citrus fruits for margaritas while outdoors in direct sunlight. The diagnosis of phytophotodermatitis is often made clinically but can be complicated due to its similarity in appearance to many other common cutaneous reactions. In this patient, the differential diagnosis included solar erythema, contact dermatitis (type IV hypersensitivity reaction), polymorphic light eruption, or drug-related photosensitivity. Careful history taking is essential in not only narrowing down the differential diagnosis but also in avoiding unnecessary tests or ineffective treatments.

Integrated approaches to testing and assessment as a tool for the hazard assessment and risk characterization of cosmetic preservatives.

The safety assessment of cosmetic products is based on the safety of the ingredients, which requires information on chemical structures, toxicological profiles, and exposure data. Approximately 6% of the population is sensitized to cosmetic ingredients, especially preservatives and fragrances. In this context, the aim of this study was to perform a hazard assessment and risk characterization of benzalkonium chloride (BAC), benzyl alcohol (BA), caprylyl glycol (CG), ethylhexylglycerin (EG), chlorphenesin (CP), dehydroacetic acid (DHA), sodium dehydroacetate (SDH), iodopropynyl butylcarbamate (IPBC), methylchloroisothiazolinone and methylisothiazolinone (MCI/MIT), methylisothiazolinone (MIT), phenoxyethanol (PE), potassium sorbate (PS), and sodium benzoate (SB). Considering the integrated approaches to testing and assessment (IATA) and weight of evidence (WoE) as a decision tree, based on published safety reports. The hazard assessment was composed of a toxicological matrix correlating the toxicity level, defined as low (L), moderate (M), or high (H) and local or systemic exposure, considering the endpoints of skin sensitization, skin irritation, eye irritation, phototoxicity, acute oral toxicity, carcinogenicity, mutagenicity/genotoxicity, and endocrine activity. In a risk assessment approach, most preservatives had a margin of safety (MoS) above 100, except for DHA, SDH, and EG, considering the worst-case scenario (100% dermal absorption). However, isolated data do not set up a safety assessment. It is necessary to carry out a rational risk characterization considering hazard and exposure assessment to estimate the level of risk of an adverse health outcome, based on the concentration in a product, frequency of use, type of product, route of exposure, body surface location, and target population.