Photocontact dermatitis

Essential oil from Citrus depressa peel exhibits antimicrobial, antioxidant and cancer chemopreventive effects

BACKGROUND

Many diseases may be caused by pathogens and oxidative stress resulting from carcinogens. Earlier studies have highlighted the antimicrobial and antioxidant effects of plant essential oils (EO). It is crucial to effectively utilize agricultural waste to achieve a sustainable agricultural economy and protect the environment. The present study aimed to evaluate the potential benefits of EO extracted from the discarded peels of Citrus depressa Hayata (CD) and Citrus microcarpa Bunge (CM), synonyms of Citrus deliciosa Ten and Citrus japonica Thunb, respectively.

RESULTS

Gas chromatography-mass spectrometry analysis revealed that the main compounds in CD-EO were (R)-(+)-limonene (38.97%), γ-terpinene (24.39%) and linalool (6.22%), whereas, in CM-EO, the main compounds were (R)-(+)-limonene (48.00%), β-pinene (13.60%) and γ-terpinene (12.07%). CD-EO exhibited inhibitory effects on the growth of common microorganisms, including Candida albicans, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. However, CM-EO showed only inhibitory effects on E. coli. Furthermore, CD-EO exhibited superior antioxidant potential, as demonstrated by its ability to eliminate 1,1-diphenyl-2-picrylhydrazyl and 2,2'-azinobis-3-ethylbenzthiazoline-6-sulfonate free radicals. Furthermore, CD-EO at a concentration of 100 μg mL-1 significantly inhibited 12-O-tetradecanoylphorbol-13-acetate-induced cancer transformation in mouse epidermal JB6 P+ cells (P < 0.05), possibly by up-regulating protein expression of nuclear factor erythroid 2-related factor 2 and its downstream antioxidant enzymes, such as NAD(P)H:quinone oxidoreductase 1, heme oxygenase-1 and UGT1A.

CONCLUSION

These findings suggest that CD-EO exhibits inhibitory effects on pathogenic microorganisms, possesses antioxidant properties and has cancer chemopreventive potential. © 2024 Society of Chemical Industry.

Overcoming False-Negative Patch Tests: A Systematic Literature Review

Exogenous allergens, found in cosmetic products, jewelry items, antiseptics and antibacterials, plants, and solvents, can cause clinical allergic contact dermatitis (ACD). To help identify and discern which allergen is causing ACD, clinicians use patch tests, but they can yield false-negative results at times. Examining potential reasoning for false negatives is particularly helpful when a patient's history and physical examination strongly suggest ACD, and the patch test is negative. A strong history and physical presentation suggestive of ACD warrants additional patch testing or other methods to verify a false-negative patch test result. We conducted a literature review to compile various reasonings and solutions for false-negative patch tests in suspected ACD patients. Utilizing EMBASE, Scopus, PubMed, and Google Scholars, 49 articles were included by using search terms such as "False negative patch test" or "False-negative patch test" and "allergic contact dermatitis," or "ACD." Common factors that led to false-negative patch test results include low allergen concentration, inadequate percutaneous penetration, technique error, immunosuppressive therapy, and ultraviolet exposure. Potential solutions include using different vehicles, concentration, increasing reading time, repeating the patch test, intradermal testing, and repeat open application testing. If a false-negative patch test is suspected, then intradermal testing can be administered to ensure the specificity of the patch test result. Considering the main contributing factors and solutions to false-negative patch tests, clinicians can accurately diagnose ACD and administer proper treatment plans.

Review on photoprotection: a clinician’s guide to the ingredients, characteristics, adverse effects, and disease-specific benefits of chemical and physical sunscreen compounds

Photoprotection is a critical health prevention strategy to reduce the deleterious effects of ultraviolet radiation (UVR) and visible light (VL). Methods of photoprotection are reviewed in this paper, with an emphasis on sunscreen. The most appropriate sunscreen formulation for personal use depends on several factors. Active sunscreen ingredients vary in their protective effect over the UVR and VL spectrum. There are dermatologic diseases that cause photosensitivity or that are aggravated by a particular action spectrum. In these situations, sunscreen suggestions can address the specific concern. Sunscreen does not represent a single entity. Appropriate personalized sunscreen selection is critical to improve compliance and clinical outcomes. Health care providers can facilitate informed product selection with awareness of evolving sunscreen formulations and counseling patients on appropriate use. This review aims to summarize different forms of photoprotection, discuss absorption of sunscreen ingredients, possible adverse effects, and disease-specific preferences for chemical, physical or oral agents that may decrease UVR and VL harmful effects.

Occupational photoallergic contact dermatitis to thiourea in a firefighter

Thioureas are a relatively uncommon cause of allergic contact dermatitis and a rare cause of photoallergic contact dermatitis. They are primarily used as vulcanization accelerators in the production of neoprene, and common sources of exposure include gloves, shoe insoles, wet suits, and orthopedic braces. We report a multifactorial case of severe episodic photoallergic contact dermatitis to thiourea in a 29-year-old firefighter. Multiple sources of neoprene exposure were identified, including a firefighting mask, continuous positive airway pressure strap, and hockey helmet.

Contact Dermatitis: Classifications and Management

Contact dermatitis (CD) is a common inflammatory skin disease caused by exposure to contact allergens and irritants. It is also the most common reason of occupational dermatitis and contributes greatly to hand dermatitis and facial dermatitis. Besides the two major forms of contact dermatitis: allergic contact dermatitis and irritant contact dermatitis, other subtypes of CD have been recognized including immediate skin reactions, photoinduced contact dermatitis, systemic contact dermatitis, and non-eczematous contact dermatitis. CD is a great imitator which can mimic many kinds of skin diseases, such as atopic dermatitis, lichen planus, and angioedema. For the diagnosis of CD, a complete medical history, including occupational history, is very important. It can give a clue of CD and provide a list of suspected substances. Besides the well-known diagnostic test, patch testing, there are many other diagnostic tests can be used to help diagnosis of CD and identify the causative allergens, including photopatch test, skin tests for detecting of immediate contact reactions, serum allergen-specific IgE test, and qualitative and quantitative testing of allergen in the suspected materials patients exposed to and challenge test. Before the treatment, the suspected irritants or allergens should be avoided completely. This includes both the removal of the patient from the environment that contains those substances and the promotion of the metabolism and expulsion of the allergens that have been absorbed by the body. In addition, it is also important to restore the skin barrier and reduce skin inflammation through multiple treatments, such as emollients, topical corticosteroids, and antihistamines, as well as systemic corticosteroids and immunosuppressants. Early and appropriate treatments are important to prevent further deterioration and persistence of the skin condition.

Latest Evidence Regarding the Effects of Photosensitive Drugs on the Skin: Pathogenetic Mechanisms and Clinical Manifestations

Photosensitivity induced by drugs is a widely experienced problem, concerning both molecule design and clinical practice. Indeed, photo-induced cutaneous eruptions represent one of the most common drug adverse events and are frequently an important issue to consider in the therapeutic management of patients. Phototoxicity and photoallergy are the two different pathogenic mechanisms involved in photosensitization. Related cutaneous manifestations are heterogeneous, depending on the culprit drug and subject susceptibility. Here we report an updated review of the literature with respect to pathogenic mechanisms of photosensitivity, clinical manifestations, patient management, and prediction and evaluation of drug-induced photosensitivity. We present and discuss principal groups of photosensitizing drugs (antimicrobials, nonsteroidal anti-inflammatory drugs, anti-hypertensives, anti-arrhythmics, cholesterol, and glycemia-lowering agents, psychotropic drugs, chemotherapeutics, etc.) and their main damage mechanisms according to recent evidence. The link between the drug and the cutaneous manifestation is not always clear; more investigations would be helpful to better predict drug photosensitizing potential, prevent and manage cutaneous adverse events and find the most appropriate alternative therapeutic strategy.

Feeling the Burn: Phototoxicity and Photoallergy

An interaction between light's radiation and certain exogenous and endogenous substances can lead to the development of photoallergic and/or phototoxic dermatoses. Clinically, reactions may range from acute and self-limited to chronic and recurrent. Delays in diagnosis are not uncommon due to complex clinical presentations, broad differentials, and limited number of specialists who perform phototesting. Therefore, a critical understanding of these dermatoses is essential for accurate diagnosis and appropriate management. The epidemiology, light sources, mechanisms, clinical presentations, evaluation protocols, common culprits, treatments, key challenges, and future directions related to photoallergy and phototoxicity are reviewed herein.

Photobinding of Triflusal to Human Serum Albumin Investigated by Fluorescence, Proteomic Analysis, and Computational Studies

Triflusal is a platelet antiaggregant employed for the treatment and prevention of thromboembolic diseases. After administration, it is biotransformed into its active metabolite, the 2-hydroxy-4-trifluoromethylbenzoic acid (HTB). We present here an investigation on HTB photobinding to human serum albumin (HSA), the most abundant protein in plasma, using an approach that combines fluorescence, MS/MS, and peptide fingerprint analysis as well as theoretical calculations (docking and molecular dynamics simulation studies). The proteomic analysis of HTB/HSA photolysates shows that HTB addition takes place at the ε-amino groups of the Lys137, Lys199, Lys205, Lys351, Lys432, Lys525, Lys541 and Lys545 residues and involves replacement of the trifluoromethyl moiety of HTB with a new amide function. Only Lys199 is located in an internal pocket of the protein, and the remaining modified residues are placed in the external part. Docking and molecular dynamic simulation studies reveal that HTB supramolecular binding to HSA occurs in the "V-cleft" region and that the process is assisted by the presence of Glu/Asp residues in the neighborhood of the external Lys, in agreement with the experimentally observed modifications. In principle, photobinding can occur with other trifluoroaromatic compounds and may be responsible for the appearance of undesired photoallergic side effects.

Comparative assessment of local tolerance of alcohols commonly used in alcohol-based hand rubs for hand hygiene

Hand hygiene plays a key role in nosocomial infection prevention. To achieve users' adherence, products' dermal tolerance is essential. We aimed at making a comparative assessment of skin irritation and phototoxicity of the 3 alcohols commonly used in alcohol-based hand rubs (Ethanol, Propan-2-ol, Propan-1-ol) at 60, 70, 80 or 85% w/w in water or with co-formulates (hydrating, emollient and skin protective agents). In vitro validated OECD methods 439 and 432 were used. For irritation, EpiSkin™ Small Model was the chosen Reconstructed Human Epidermis (RhE). For phototoxicity, co-formulates alone or in mixture with and without alcohol were tested using BALB/c 3T3 cell cultures. Whilst Ethanol and Propan-2-ol could not be differentiated and displayed good skin tolerance profiles, Propan-1-ol based products lead to significant viability impairments of RhE at 60, 70 or 80% and at 60% in the presence of co-formulates. However, these results could not be reproduced in another RhE model. Taking also into account bibliographic data on Propan-1-ol, this suggests that our results are probably related to a lack of specificity of the used RhE. Therefore, it can be relevant in case of significant results to use two different RhE models before performing any classification and/or performing any complementary tests.

Photosensitivity to Exogenous Agents

Objective:

To better understand cutaneous photosensitivity reactions, a review of its etiologic factors, clinical characteristics, pathogenesis, and treatment modalities was undertaken.

Methods:

Articles discussing the above aspects of phototoxic and photoallergic reactions were used to demonstrate what is currently known about photoinduced reactions and how to treat them.

Results:

Upon interaction of solar UV radiation with the chemical that is present in significant levels on the skin, one of two known reactions may occur in susceptible patients: a phototoxicity and/or photoallergy. Phototoxic and photoallergic reactions can be diagnosed separately on the basis of pathogenesis, clinical characteristics, and histology. Examples of drugs capable of inducing a phototoxic reaction include amiodarone, retinoids, nonsteroidal antiinflammatory agents, diuretics, and antibiotics. Substances known to cause a photoallergic response are fragrances, sunscreens, topical antimicrobials, NSAID, and psychiatric medications, such as chlorpromezine.

Conclusion:

Photoinduced reactions produced by exogenous chemicals are common skin disorders. Definitive therapy requires identifying and removing the offending agent, either the photosensitizing chemical or light. The use of fully protective clothing and a sunscreen of high SPF are important measures when light exposure is inevitable.

Contact dermatitis: a practice parameter-update 2015

This parameter was developed by the Joint Task Force on Practice Parameters, which represents the American Academy of Allergy, Asthma & Immunology (AAAAI); the American College of Allergy, Asthma & Immunology (ACAAI); and the Joint Council of Allergy, Asthma & Immunology. The AAAAI and the ACAAI have jointly accepted responsibility for establishing "Contact Dermatitis: A Practice Parameter-Update 2015." This is a complete and comprehensive document at the current time. The medical environment is changing and not all recommendations will be appropriate or applicable to all patients. Because this document incorporated the efforts of many participants, no single individual, including members serving on the Joint Task Force, are authorized to provide an official AAAAI or ACAAI interpretation of these practice parameters. Any request for information or interpretation of this practice parameter by the AAAAI or ACAAI should be directed to the Executive Offices of the AAAAI, the ACAAI, and the Joint Council of Allergy, Asthma & Immunology. These parameters are not designed for use by the pharmaceutical industry in drug development or promotion. Previously published practice parameters of the Joint Task Force on Practice Parameters for Allergy & Immunology are available at http://www.JCAAI.org or http://www.allergyparameters.org.

Photopatch testing in Bogota (Colombia): 2011-2013

BACKGROUND

Photopatch tests are used to diagnose photoallergic contact dermatitis and identify the causal agents. The frequencies of positive results and associated allergens vary by country; therefore, it is necessary to know the information specific to each country.

OBJECTIVE

To establish the frequency of positive photopatch test results, and their relevance, in patients with suspected photoallergic contact dermatitis in a national dermatology centre located in Bogota, Colombia.

MATERIALS AND METHODS

One hundred patients investigated for possible photoallergic contact dermatitis were enrolled in the study. They were photopatch tested with a selected group of allergens, and occluded for 48 hours; the duplicate right-hand panel was irradiated with 5 J/cm(2) ultraviolet (UV)A. The readings were performed on day (D)2, D4, and D6, in accordance with the guidelines of the ICDRG, and the relevance was evaluated with the COADEX system.

RESULTS

There were a total of 20 photopatch reactions in 15 patients, 95% of which were caused by UV filters, most frequently benzophenone-3 (55%). Eight of the positive reactions (53.3%) appeared on D6.

CONCLUSIONS

UV filters continue to be the most common causes of photoallergic contact dermatitis in our patients. Readings up to D6 (96 h after irradiation) are important to identify delayed positive reactions.

Development of a clinical score system for the diagnosis of photoallergic contact dermatitis using a consensus process: item selection and reliability

BACKGROUND

Photoallergic contact dermatitis (PACD) is an uncommon condition, and there is a lack of validated criteria for its diagnosis.

OBJECTIVE

To identify a set of relevant criteria to be considered when suspecting a diagnosis of PACD and to assess the reproducibility of these criteria.

METHODS

This was a diagnostic item selection and reliability study performed between July 2012 and October 2012. A panel of seven recognized experts was invited to consecutive rounds of a Delphi survey and to a conclusive face-to-face meeting with the aim of obtaining an agreement on criteria for the diagnosis of PACD. The panel was also provided with a series of 16 reports of suspected PACDs to be classified according to a five-point likelihood scale. Identified criteria with the weights attributed by experts were used to develop a score system for the diagnosis of PACD. Consensus was measured by calculating the Intraclass Correlation Coefficient (ICC). The performance of the score system was evaluated in terms of overall classification accuracy.

RESULTS

Seven criteria were identified by experts as relevant for the diagnosis of PACD. The criteria were related to the type of skin lesions, accompanying symptoms, skin area involved, general medical history, modality of exposure to the culprit substance, history of exposure to the sun or other light sources and photopatch test results. Experts reached a moderate agreement on PACD cases classification, with ICC = 0.69 (95% Confidence Interval, CI, 0.50-0.86). The score system enabled discrimination of probable and definite PACD cases from possible and unlikely or excluded ones, with a nearly perfect agreement being observed between the score system classification and judgment by experts.

CONCLUSION

A diagnostic score was proposed. The score should receive a comprehensive validation on a larger series of cases and with multiple evaluators.

Vandetanib-induced phototoxicity in human keratinocytes NCTC-2544

The phototoxicity of the new anticancer drug vandetanib was evaluated using human keratinocyte cell line, NCTC-2544. This study was started since many clinical cases of vandetanib photosensitizing reactions were recently reported in literature. Vandetanib induces a clear drop in human keratinocytes viability after cell irradiation in concentration and UV-A dose dependent mode. Since vandetanib can photolyze with the formation of two main photoproducts after UV-A exposure, the contribution of these new species was also evaluated. These two photoproducts did not have a main role in the phototoxicity of their parent drug. In our opinion, the main hypothesis for the vandetanib phototoxic potential is the formation of a very reactive specie, such as an aryl radical, which can react promptly with different targets inside the cells. In fact, a massive DNA photodamage was detected both in the in vitro DNA photocleavage experiments, and in cells. Moreover, vandetanib was able to photoinduce lipid peroxidation and protein oxidations. Vandetanib photoinduced cell death by apoptosis with the involvement of mitochondria and lysosomes.

Current sunscreen controversies: a critical review

BACKGROUND/PURPOSE

Sunscreens are believed to be a valuable tool in providing photoprotection against the detrimental effects of UV radiation, a known carcinogen. However, a number of controversies have developed regarding their safety and efficacy. This review summarizes the relevant studies surrounding these controversies.

METHODS

Evidence of the prevention of skin cancer, an oft-cited reason for sunscreen use, was examined as it pertains to squamous cell carcinoma, basal cell carcinoma and melanoma. We also reviewed studies examining the effects of sunscreen on the synthesis of vitamin D, an essential nutrient whose role in health and disease continues to grow. Lastly, we analyzed studies surrounding the safety and toxicity of oxybenzone, retinyl palmitate and nanoparticles of zinc oxide (ZnO) and titanium dioxide (TiO2 ).

RESULTS

The overwhelming majority of available data is drawn from studies conducted using antiquated sunscreen formulations. Nonetheless, our research revealed that topical use of sunscreen protects against squamous cell carcinoma, does not cause vitamin D deficiency/insufficiency in practice and has not been demonstrated to adversely affect the health of humans.

CONCLUSION

Given the established benefits of UV protection, the use of sunscreens remains an important part of an overall photoprotective strategy. Future sunscreens with improved formulation should ideally offer superior protection. With increased usage of sunscreen by the public, continuous and vigilant monitoring of the overall safety of future products is also needed.

Chronic Actinic Dermatitis: Clinical Cases, Diagnostic Workup, and Therapeutic Management

Background:

We report four cases of chronic actinic dermatitis (CAD) occurring in middle-aged men with significant outdoor exposure.

Objective:

The aim of this report is to show the spectrum of presentations of patients with CAD and to outline the proper diagnostic workup of these individuals.

Methods:

Phototesting was performed to determine the minimal erythema doses to ultraviolet (UV)A (315–400 nm) and UVB (280–315 nm) and photopatch testing and patch testing for each individual with the North American Contact Dermatitis Group Standard series and the Chemotechnique Plant series, supplemented by the Hausen Plant series and the patients' own products.

Results:

All patients were men, over 45 years, who worked outdoors or had outdoor hobbies. Two had a past known history of allergic contact dermatitis. Two had atopic dermatitis. Three had positive reactions to Compositae plants and sesquiterpene lactone; one had a reaction to lichen acid mix. All had photocontact dermatitis or contact dermatitis to sunscreen chemicals, including benzophenone 3 (oxybenzone), butyl methoxydibenzoylmethane (avobenzone), and ethylhexyl methoxycinnamate (octinoxate). All reacted to fragrance mix; two reacted to balsam of Peru and two to colophony. All had biopsies showing an eczematous pattern.

Conclusion:

CAD is persistent, with a classic presentation, and requires a specific diagnostic workup. Effective therapeutic options exist for patients with CAD.

Nichthereditäre Photodermatosen im Kindesalter

Non-hereditary photodermatoses with well-known trigger factors and idiopathic light eruptions occur quite frequently during childhood and are at least temporarily associated with a marked impairment of quality of life in affected patients and their parents. Thus, it is crucial that the involved specialties are familiar with acquired UV-associated disorders in order to guarantee a quick diagnosis and effective therapy. Additionally, the recurrence of photodermatoses associated with potentially severe long-term complications has to be prevented. This requires a stringent prophylaxis that can only succeed after age-adapted instruction of the patient and parents.

Causal agents of photoallergic contact dermatitis diagnosed in the national institute of dermatology of Colombia

OBJECTIVE

To describe and identify the photoallergens causing photoallergic contact dermatitis in the population attending the outpatient clinic of the Centro Dermatologico Federico Lleras Acosta (CDFLLA), the National Institute of Dermatology of Colombia.

MATERIALS AND METHODS

Eighty-two patients with clinical diagnosis of photoallergic contact dermatitis enter the study. These patients attended the CDFLLA between August 2001 and May 2003. Photopatch tests were performed using the standard series of sunscreens (Chemotechnique Diagnostics) and 6-methylcoumarin. Cetyl alcohol, phenoxyethanol, methylparabene, propylene glycol, triethanolamine, propylparabene, trichlorocarbanilide and dichromate were also included. The allergens were applied in duplicate on the healthy skin of the back and covered with opaque tape withdrawn 24 h later, the panel on the right was irradiated with an ultraviolet A dose of 5 J/cm(2). The tests were read 24 h after the application of the allergens, 24 and 72 h post-irradiation. The readings were assessed according to the visual scoring system recommended by the International Contact Dermatitis Research Group.

RESULTS

Twenty-six patients (31.7%) showed positive photopatch test responses to one or several allergens. Four of them showed positive results to three components of the series and four patients to two components. Thirty-eight photoallergic and 18 allergic reactions were observed. Ultraviolet filters were the substances which more frequently produced positive photopatch test responses (30.5%). The most common ultraviolet filter photoallergen was benzophenone-3 with 22/82 positive results (26.8%), followed by octyl methoxycinnamate (8/82), benzophenone-4 and mexenone (2/82), phenylbenzimidazole sulphonic acid, methylbenziliden camphor and octyl dimethyl PABA (1/82). One patient showed a photoallergic response to 6-methylcoumarin. There was a concordance between the allergen which elicited the positive response and the use of different substances which contained that molecule among its compounds in 17 patients (65.3%). 19.5% of the patients (16/82) showed positive results to one or several allergens in the irradiated panel as well as in the unirradiated control site. These cases were diagnosed as contact allergy, probably caused by aeroallergens, presenting a natural history and a clinical picture similar to photocontact allergy. The most common allergen was dichromate with 10 positive results.

CONCLUSIONS

The results of this study confirm that sunscreens are the more frequently involved substances in photoallergic contact dermatitis in our population. Identification of the photoallergen is the key element for adequate disease control and patient education.

Sunscreen Allergy: A Review of Epidemiology, Clinical Characteristics, and Responsible Allergens

Although allergy to sunscreen represents a small proportion (< 1%) of allergic contact dermatitis reactions in North America, it is one of the most common causes of photoallergy. The epidemiology and clinical characteristics of sunscreen allergy are summarized in this review. In addition, a detailed discussion of specific chemical sunscreen allergens is provided.

Photosensitivity to Exogenous Agents

OBJECTIVE

To better understand cutaneous photosensitivity reactions, a review of its etiologic factors, clinical characteristics, pathogenesis, and treatment modalities was undertaken.

METHODS

Articles discussing the above aspects of phototoxic and photoallergic reactions were used to demonstrate what is currently known about photoinduced reactions and how to treat them.

RESULTS

Upon interaction of solar UV radiation with the chemical that is present in significant levels on the skin, one of two known reactions may occur in susceptible patients: a phototoxicity and/or photoallergy. Phototoxic and photoallergic reactions can be diagnosed separately on the basis of pathogenesis, clinical characteristics, and histology. Examples of drugs capable of inducing a phototoxic reaction include amiodarone, retinoids, nonsteroidal antiinflammatory agents, diuretics, and antibiotics. Substances known to cause a photoallergic response are fragrances, sunscreens, topical antimicrobials, NSAID, and psychiatric medications, such as chlorpromezine.

CONCLUSION

Photoinduced reactions produced by exogenous chemicals are common skin disorders. Definitive therapy requires identifying and removing the offending agent, either the photosensitizing chemical or light. The use of fully protective clothing and a sunscreen of high SPF are important measures when light exposure is inevitable.