Irritant Contact Research Articles

Efficacy of botanical repellents on major pests - A review

One of the most common strategies in managing insect pests is repellence. This technology comes from early farming practices. The worldwide evaluation aims to evaluate the current state of research and development on the repellent properties of various botanical products to incorporate them reliably into pest management systems. As a result, many countries are returning to plant-based repellants to combat pest insects and vertebrates. Olfaction and gustatory action are the two mechanisms used by plant-derived repellents. It can be classified by their modes of action, including genuine repellents, attraction inhibitors, contact irritants, antifeedants or deterrents and visual barriers. Ecologists are concerned about the potential harm contemporary pest control methods may pose to vertebrate wildlife. Therefore, caution is needed in agricultural settings when treating major pest groups, such as beetles, whiteflies, fruit flies, honey bees and vertebrate pests. Botanicals have significant advantages, being eco-friendly, non-phytotoxic and safe for both the agroecosystem and the environment. In modern agriculture, synthetic pesticides or repellents are crucial in helping farmers control pests. However, it may harm non-target insects, cause significant environmental contamination and affect human health. The current review revisits the urgent and comprehensive needs that must be met to conduct additional research on both known and unknown plants that contain compounds that repel pestiferous taxa throughout agroecosystems. These plants have the potential to be widely utilized as botanical biopesticides, but current research is increasingly focused on their bio-repellent properties, both globally and in India.

An investigation on the use of topical antibiotics for treating eczema and dermatitis in China

Introduction: Bacterial infection secondary to eczema and dermatitis occurs frequently. However, due to the inconvenience of clinical bacterial culture procedure, clinical diagnosis of bacterial infection following eczema is typically based on the appearance of skin lesions. To date, no surveys on the use of topical antibiotics for treating eczema and dermatitis in China have been carried out. Methods: The present study investigated the factors influencing the use of topical antibiotics to treat eczema and dermatitis in China. Logistic regression model and chi-square test were employed to examine whether topical antibiotics cause contact irritation. Results: It was found that the proportion of patients with eczema and dermatitis who were previously treated with topical antibiotics was 72.40%. The patients’ residence regions (southern vs northern territories, p < .001), hospital levels (secondary-level and below vs third-level hospitals, p = .004), itching degrees (no itching, itching does not require scratching, itching requires scratching, and scratching affects sleep and life quality, p < .001), skin infection status (no obvious infection phenomenon, possible infection, and clear infection, p = .001), and skin lesion infection severity (mild, moderate, and severe, p < .001) all showed statistically significant differences in the univariate analysis of antibiotic ointment treatment factors. The percentage of patients experiencing contact irritation reactions resulting from the use of topical antibiotics was 2.60%. The incidence of exposure to irritation was higher in patients who used more than two types of topical antibiotics compared to patients treated with only one type of topical antibiotic (% vs %, chi-square test, p < .001). Conclusion: The number of individuals who used topical antibiotics for eczema and dermatitis was relatively high in China. The degree of itching, infection possibility, and degree of skin lesion infection were positively correlated with the patients’ previous topical antibiotic treatment.

Study of antimicrobial efficacy of garlic oil loaded ethosome against clinical microbial isolates of diverse origin

IntroductionGarlic oil (GO), a steam-distilled product of Garlic (Allium sativum) has been successfully used as an antiseptic, antimicrobial, antioxidant and anti-inflammatory agent for decades. However, the contact irritation and volatility are practical limitations in their use. This study aimed to evaluate the in-vitro antimicrobial efficacy of garlic oil (GO) encapsulated ethosome against the microbial isolates of diverse origins as well as the effect of the storage temperature on antimicrobial efficacy. MethodsThe GO ethosomes were prepared by cold method and characterised for particle size distribution, morphology by Scanning Electron Microscopy (SEM) and molecular fingerprinting by Fourier-transform infrared spectroscopy (FT-IR) and release kinetics. ResultsThe GO ethosomes at a concentration of 25 µg/ml was found effective against all tested isolates, whereas at a concentration of 12.5 µg/ml and 6.25 µg/ml it was found effective against 146/147 and 139/147 isolates respectively. The average zone of inhibition (ZI) was 33.5 mm (25 µg/ml), 30.1 mm (12.5 µg/ml) and 24.0 mm (6.25 µg/ml). The minimum inhibitory concentration (MIC) values remain relatively constant against reference strain S. aureus (ATCC 29312 and ATCC 43300) and E. coli (NDM) at 0 days to 265 days. The minimum bactericidal concentration (MBC) values against the majority of isolates were in the range of 125–250 µg/ml. The in-vitro release data showed zero order kinetics, and best-fit release model was Korsmeyer-peppas and Weibull. ConclusionThe study demonstrated that the encapsulation of GO preserves the antimicrobial efficacy and storage for 265 days at room temperature did not alter the efficacy, suggesting wider applications in therapeutics to food preservation.

Behavioral responses of field-collected German cockroaches to pyrethroids and pyrethroid-formulated insecticides.

Pyrethroids are synthetic insecticides with low mammalian toxicity and broad-spectrum activity across insects. One major challenge with pyrethroids is their perceived repellency. This perception can influence decisions made by pest control operators, especially when insecticides are used to reduce insect entry into or movement within structures. One major indoor pest that has been repeatedly shown to be repelled by some pyrethroids is the German cockroach, Blattella germanica. However, most experiments evaluating pyrethroid repellency in the German cockroach have used end-point assays, which do not provide information on the movement that led to the final position. Therefore, we evaluated the kinetic behavioral response of field-collected German cockroaches to five pyrethroid-based products and their active ingredients (A.I.) in open behavioral arenas using advanced video tracking software. In addition, in an effort to compare our free-moving experiments with end-point assays, we evaluated sheltering behavior using two-choice harborage arrestment assays where German cockroaches were provided a choice between pyrethroid-treated and untreated shelters. All pyrethroid-formulated products and their respective A.I.'s failed to affect field-collected German cockroach movement behavior in free-moving assays, while positive controls (DEET, corn mint oil) resulted in reduced time spent by German cockroaches in treated areas. However, despite their willingness to move over pyrethroids-treated surfaces, field-collected German cockroaches displayed a reduced propensity to arrest on pyrethroids treated tents. While most pyrethroids/pyrethroid-formulated products affected German cockroach arrestment, pyrethroids and pyrethroid-formulated products failed to change German cockroach movement behavior in free-moving assays. These results indicate the pyrethroids tested act as contact irritants rather than true-spatial repellents on field-collected German cockroaches. This distinction is critical to refining pest management strategies involving pyrethroids. © 2023 Society of Chemical Industry.

A CLINICO-ETIOLOGICAL STUDY ON BALANOPOSTHITIS

Background: Balanoposthitis is a relatively common condition affecting both pediatric patients and adults. In adults, uncircumcised males with diabetes mellitus are at the highest risk, with higher prevalence. Although majority of patients will respond to changes in hygiene and empiric therapy, about one in ten will show recurrence needing further evaluation and more targeted management. Aims And Objectives: To study the clinical features in patients of Balanoposthitis, and to determine the etiological agents by microbiological spectrum and the risk factors associated with it. Materials And Methods: The present hospital based cross-sectional study was conducted for a period of 18 months on 75 patients with clinically diagnosed balanoposthitis visiting outpatient and inpatient under the Department of Dermatology, Venerology and Leprosy of Basaveshwar teaching and general hospital attached to Mahadevappa Rampure Medical College, Kalaburagi. A pre-designed semi-structured proforma, which was internally validated was used to collect the necessary information on all the needed variables. Demographic details were recorded and a detailed history of symptoms, history of external application, and history of systemic illness was obtained. The systemic and genital examination was done. Subpreputial discharge was collected on swabs and sent for KOH mount, bacterial and fungal culture. Results: In the present study, the mean age was estimated to be 44.60 ± 10.49 years. Majority were married (90.7%), had completed just high school education (90.7%). On enquiring whether any topical agents were applied in the past, only 10.7% had agreed to it. Subpreputial discharge was found to be the most common clinical feature (72.0%), followed by erythema (54.7%). The involvement of preputial skin was observed in about 44.0% cases. Herpes genitalis was evident in 5.3% cases, while syphilis was present in only 1 individual, and 3 other subjects were positive for HIV infection. The only complication was non-retractable prepuce, which was appreciated in about 9.3% cases. About 74.1% of the subjects showed positive for KOH Mount. However, among them, only 35 individuals were found to be positive on fungal culture. Staphylococcus aureus was the most common bacteria (25.9%), followed by staphylococcus epidermis (22.2%). Diabetes mellitus was regarded as commonly associated risk factor (74.7%). The commonest infectious etiology was observed to be bacterial infection (73.3%), followed by fungal infection (46.7%). The commonest non-infectious etiologies were observed to be adverse drug reaction and irritant contact. Conclusion: Subpreputial discharge was found to be the most common clinical feature followed by erythema, fissures over preputial skin and ulcer. Bacterial and fungal infection were common infectious etiologies while adverse drug reaction and irritant contact were non-infectious etiologies causing Balanoposthitis. Co-morbidities such as diabetes mellitus and hypertension were regarded as the risk factors associated with Balanoposthitis.

Topikalne farmaceutske formulacije za negu kože izložene jonizujućem zračenju

Radiotherapy as the application of ionizing radiation is one of the main current therapeutic modalities for cancer. However, one of the most frequent adverse effects of this therapeutic strategy is radiodermatitis, which significantly affects quality of patients' lives. Nowadays, there is no consensus on the appropriate therapy of radiodermatitis, however there are basic recommendations that should be followed. The aim of this study was to make a review of current recommendations during radiotherapy for the prevention of radiodermatitis through application or avoidance of application of certain topical pharmaceutical formulations. Most studies proposed the adequate personal hygiene as a general preventive measure. Basic recommendations also include wearing loose-fitting clothing, using an electric shaver, sunscreens, moisturizers, and avoiding alcohol and cigarettes. According to the Multinational Association of Supportive Care in Cancer (MASCC), the only recommendation for the prevention and treatment of radiodermatitis is gentle washing using mild soap, as well as the use of topical steroids and silver sulfadiazine. Some studies report the possibility of using photobiomodulatory therapy in the prevention of radiodermatitis, as well as non-corticosteroid creams based on aloe, hyaluronic acid, calendula and comfrey. The use of comedogenic topical preparations, those containing alcohol, benzoyl peroxide and/or alpha-hydroxy acids, as well as those containing potential contact allergens and irritants, should be avoided. Adequate guidelines supported by strong evidence and consensus do not exist, and many recommendations were later refuted. Therefore, further research in this field is necessary to find a satisfying solution for an issue of radiation dermatitis.

Lipidomics Profile Change of Skin Surface Lipids in Nummular Eczema

Nummular eczema (NE), first introduced by Devegie in 1857, is chronic dermatitis characterized by oval or coin-shaped lesions with distinct boundaries, usually accompanied by severe pruritus (Leung et al., 2020). Although, its pathophysiological characteristics are still scarcely available, various factors have been reported to be implicated such as nutrition, infection, alcohol intake, dry skin, contact irritation and sensitivity (Bonamonte et al., 2012). Besides controlling inflammation, management is aimed at reducing skin dryness and restoring the skin barrier, which improves xerosis and irritation (Leung et al., 2020).

Allergy Electronic Health Record Documentation: A 2022 Work Group Report of the AAAAI Adverse Reactions to Drugs, Biologicals, and Latex Committee

The allergy section of the electronic health record (EHR) is ideally reviewed and updated by health care workers during routine outpatient visits, emergency room visits, inpatient hospitalizations, and surgical procedures. This EHR section has the potential to help proactively and comprehensively avoid exposures to drugs, contact irritants, foods, and other agents for which, based on an individual's medical history and/or genetics, there is increased risk for adverse outcomes with future exposures. Because clinical decisions are made and clinical decision support is triggered based on allergy details from the EHR, the allergy module needs to provide meaningful, accurate, timely, and comprehensive allergy information. Although the allergy section of the EHR must meet these requirements to guide appropriate clinical decisions and treatment plans, current EHR allergy modules have not achieved this standard. We urge EHR vendors to collaborate with allergists to optimize and modernize allergy documentation. A work group within the Adverse Reactions to Drugs, Biologicals, and Latex Committee of the American Academy of Allergy, Asthma & Immunology was formed to create recommendations for allergy documentation in the EHR. Whereas it is recognized that the term "allergy" is often used incorrectly because most adverse drug reactions (ADRs) are not true immune-mediated hypersensitivity reactions, "allergy" in this article includes allergies and hypersensitivities as well as side effects and intolerances. Our primary objective is to provide guidance for the current state of allergy documentation in the EHR. This guidance includes clarification of the definition of specific ADR types, reconciliation of confirmed ADRs, and removal of disproved or erroneous ADRs. This document includes a proposal for the creation, education, and implementation of a drug allergy labeling system that may allow for more accurate EHR documentation for improved patient safety.

Excito-repellency of Myristica fragrans Houtt. and Curcuma longa L. extracts from Southern Thailand against Aedes aegypti (L.).

The development of local plant extracts as a mosquito repellent is environmentally safe, inexpensive, and easily accessible for residents. In this study, three extracts from two local plants, Myristica fragrans Houtt. (flesh and mace) and Curcuma longa L. (rhizome) from southern Thailand, were investigated for their inherent repellent activity using the excito-repellency (ER) assay system against insectary-colonized Aedes aegypti (L.) (Diptera: Culicidae). The escape responses of mosquitoes exposed to concentrations of 0.5% to 5.0% (w/v) were measured to determine the contact irritant and non-contact repellent properties of each extract. Both the flesh and mace extracts of M. fragrans had relatively limited contact irritants (28.1% and 34.6% escape) and non-contact repellent (16.7% and 18.3% escape) activities against Ae. aegypti, respectively. The C. longa rhizome extract produced higher escape responses in the non-contact (42.6% escape) and contact (41.4% escape) trials at concentrations of 5.0% and 1.0%, respectively. GC-MS analysis found diethyl malate (56.5%) and elemicin (11.7%) to be the main components of the flesh and mace extracts, respectively, while ar-turmerone (24.6%), β-turmerone (15.2%), α-turmerone (10.5%) were the primary constituents of the rhizome extract. Overall, our results indicate that both M. fragrans extracts primarily caused Ae. aegypti escape through contact irritation. For C. longa, lower concentrations (0.5% and 1.0%) exhibited contact irritancy, but higher concentrations (2.5% and 5.0%) exhibited non-contact repellency against Ae. aegypti. Although they had limited efficacy, further experiments (e.g., mixing with other plant-based compounds) could enhance the ER of both local plant extracts. Additional evaluation of these extracts against other mosquito species and the ER of their chemical components, either alone or in combination, would also be beneficial for the development of green repellents. Our findings emphasize the possibility of utilizing plant-based mosquito repellent as an alternative personal protection method for future mosquito control programs.

Gene profiling reveals a contact allergy signature in most positive Amerchol L-101 patch test reactions.

Diagnosis of contact allergy (CA) to Amerchol L-101 (AL-101), a marker for lanolin allergy, is problematic. Positive patch test reactions are frequently doubtful or weakly positive and difficult to associate with clinical relevance. To gain further insight on the allergic or irritant nature of skin reactions induced by AL-101 patch test. We re-tested in a dose-response fashion, 10 subjects with AL-101 CA and performed comprehensive transcriptomic analysis (gene arrays, quantitative real-time polymerase chain reaction [qRT-PCR]) of samples of their skin reactions. Eight of the 10 CA subjects reacted positively upon re-test, whereas two did not react. Most of AL-101 positive patch tests expressed an allergy signature with strong activation of gene modules associated with adaptive immunity and downregulation of cornification pathway genes. In addition, the breadth of gene modulation correlated with the magnitude of patch test reactions and the concentration of AL-101 applied. However, we observed that some of the positive patch test reactions to AL-101 expressed no/few allergy biomarkers, suggesting the induction of an irritant skin inflammation in these samples. This study confirms that AL-101 is an allergen that can cause both contact allergy and contact irritation. Our results also highlight that molecular profiling might help to strengthen clinical diagnosis.

Novel insights into contact dermatitis

Contact dermatitis is a common disease that is caused by repeated skin contact with contact allergens or irritants, resulting in allergic contact dermatitis (ACD) and/or irritant contact dermatitis. Attempts have been made to identify biomarkers to distinguish irritant and allergic patch test reactions, which could aid diagnosis. Some promising candidates have recently been identified, but verification and validation in clinical cases still need to be done. New causes of ACD are constantly being recognized. In this review, 10 new contact allergens from recent years, several relating to anti-aging products, have been identified. Frequent allergens causing considerable morbidity in the population, such as the preservative methylisothiazolinone, have been regulated in the European Union. Asignificant drop in the number of cases has been seen, whereas high rates are still occurring in other areas such as North America. Other frequent causes are fragrance allergens, especially the widely used terpenes and acrylates found in medical devices for control of diabetes. These represent unsolved problems. Recent advances in immunology have opened the way for a better understanding of the complexity of contact dermatitis, especially ACD-a disease that may be more heterogenous that previous understood, with several subtypes. With the rapidly evolving molecular understanding of ACD, the potential for development of new drugs for personalized treatment of contact dermatitis is considerable.

Skin lesions associated with personal protective equipment in medical workers during the COVID-19 pandemic

Aim. Analysis of the incidence of personal protective equipment (PPE)-associated dermatoses among medical workers during the COVID-19 pandemic.Materials and Methods. Screening of the papers indexed by PubMed, EMBASE, Google Scholar, eLibrary, and UpToDate databases, written in English and published from January 1, 2020 to October, 2021. The search keywords were: "medical workers", "skin", "dermatoses", "professional", and "personal protective equipment" in combination with "COVID-19" and "SARS-CoV-2".Results. Occupational contact dermatitis is responsible for 20% of all cases of contact dermatitis which accounts for 90% of all skin disease cases. During the COVID-19 pandemic, from 42.8% to 97.0% of medical workers reported about skin lesions provoked by prolonged wearing of PPE in combination with regular disinfection. About 61.7% of them noted the deterioration of a pre-existing skin disease, and 90.5% reported the appearance of new skin lesion symptoms associated with the PPE usage. The most common symptoms of skin lesions among medical workers were dryness, itching, burning, soreness, and skin rash. Irritant and allergic contact dermatitis, acne, rosacea, and seborrheic dermatitis were the most prevalent skin disorders among the interviewed medical workers. Risk factors for the development of PPE-associated dermatoses were the type and material of PPE, the duration of PPE wearing, and past medical history of skin diseases. Due to the increased incidence of PPE-associated dermatoses among the medical staff, some countries have developed recommendations on the prevention and treatment of undesirable PPE-associated skin reactions in medical professionals. Current research are focused on developing special tools and devices that would serve as a protective barrier between the skin and PPE, ameliorating the damaging effect of the latter.Conclusion. PPE-associated dermatoses are currently widespread among the medical workers, highlighting the need in novel materials for PPE manufacturing to minimise the risk of developing PPE-associated skin lesions.

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.

Unique molecular signatures typify skin inflammation induced by chemical allergens and irritants.

Skin exposure to chemicals may induce an inflammatory disease known as contact dermatitis(CD). Distinguishing the allergic and irritant forms of CD often proves challenging in the clinic. To characterize the molecular signatures of chemical-induced skin inflammation, we conducted a comprehensive transcriptomic analysis on the skin lesions of 47 patients with positive patch tests to reference contact allergens and nonallergenic irritants. A clear segregation was observed between allergen- and irritant-induced gene profiles. Distinct modules pertaining to the epidermal compartment, metabolism, and proliferation were induced by both contact allergens and irritants; whereas only contact allergens prompted strong activation of adaptive immunity, notably of cytotoxic T-cell responses. Our results also confirmed that: (a) unique pathways characterize allergen- and irritant-induced dermatitis; (b) the intensity of the clinical reaction correlates with the magnitude of immune activation. Finally, using a machine-learning approach, we identified and validated several minimal combinations of biomarkers to distinguish contact allergy from irritation. These results highlight the value of molecular profiling of chemical-induced skin inflammation for improving the diagnosis of allergic versus irritant contact dermatitis.

A Case of Contact Irritation Dermatitis Accompanied by Dissolution of Nail Caused by Combination of Povidone Iodine and Dasuqing

A Case of Contact Irritation Dermatitis Accompanied by Dissolution of Nail Caused by Combination of Povidone Iodine and Dasuqing

New Approach Methodology for Assessing Inhalation Risks of a Contact Respiratory Cytotoxicant: Computational Fluid Dynamics-Based Aerosol Dosimetry Modeling for Cross-Species and In Vitro Comparisons.

Regulatory agencies are considering alternative approaches to assessing inhalation toxicity that utilizes in vitro studies with human cells and in silico modeling in lieu of additional animal studies. In support of this goal, computational fluid-particle dynamics models were developed to estimate site-specific deposition of inhaled aerosols containing the fungicide, chlorothalonil, in the rat and human for comparisons to prior rat inhalation studies and new human in vitro studies. Under bioassay conditions, the deposition was predicted to be greatest at the front of the rat nose followed by the anterior transitional epithelium and larynx corresponding to regions most sensitive to local contact irritation and cytotoxicity. For humans, simulations of aerosol deposition covering potential occupational or residential exposures (1–50 µm diameter) were conducted using nasal and oral breathing. Aerosols in the 1–5 µm range readily penetrated the deep region of the human lung following both oral and nasal breathing. Under actual use conditions (aerosol formulations >10 µm), the majority of deposited doses were in the upper conducting airways. Beyond the nose or mouth, the greatest deposition in the pharynx, larynx, trachea, and bronchi was predicted for aerosols in the 10–20 µm size range. Only small amounts of aerosols >20 µm penetrated past the pharyngeal region. Using the ICRP clearance model, local retained tissue dose metrics including maximal concentrations and areas under the curve were calculated for each airway region following repeated occupational exposures. These results are directly comparable with benchmark doses from in vitro toxicity studies in human cells leading to estimated human equivalent concentrations that reduce the reliance on animals for risk assessments.

Pentachlorophenol and nine other chlorophenols in urine of children and adolescents in Germany – Human biomonitoring results of the German Environmental Survey 2014–2017 (GerES V)

Chlorophenols comprise of a large group of chemicals used inter alia for the production of biocides, pharmaceuticals, other industrial products and are used e.g. as antiseptics or wood preservatives due to their biocidal properties. Several of them are classified as toxic to aquatic life and harmful to humans by ingestion, inhalation, or dermal contact, causing skin and eye irritation. Moreover, chlorophenols are possibly carcinogenic to humans. The most prominent chlorophenol – pentachlorophenol – is carcinogenic to humans, was banned in Germany in 1989 and further regulated by the European Commission in 2006 and included in the Stockholm Convention in 2017. Some chlorophenols are persistent in the environment and are also biodegradation products of precursor substances. To evaluate the health-relevance of recent exposure and monitor the effectiveness of regulatory measures, chlorophenols were analysed in the population-representative German Environmental Survey on Children and Adolescents 2014–2017 (GerES V). First-morning void urine samples of 485 3-17-year-old children and adolescents were analysed for ten chlorophenols.Pentachlorophenol was still quantified in 87% of the children and adolescents with a geometric mean (GM) concentration of 0.19 μg/L (0.16 μg/gcrea) and a maximum concentration of 6.7 μg/L (5.4 μg/gcrea). The maximum concentration was well below the health-based guidance value HBM-I of 25 μg/L (20 μg/gcrea). 4-Monochlorophenol was quantified in all samples with a GM concentration of 1.38 μg/L (1.14 μg/gcrea). 2-Monochlorophenol, 2,4-dichlorophenol, and 2,5-dichlorophenol were quantified in 97%, 98%, and 95% of the samples, with GMs of 0.26 μg/L (0.21 μg/gcrea), 0.24 μg/L (0.20 μg/gcrea), and 0.26 μg/L (0.21 μg/gcrea). 2,6-dichlorophenol, 2,3,4-trichlorophenol, and 2,4,5-trichlorophenol were quantified in 17–25% of the samples with GMs below the limit of quantification (LOQ) of 0.1 μg/L 2,4,6-trichlorophenol was quantified in 72% of the samples (GM: 0.13 μg/L, 0.11 μg/gcrea), 2,3,4,6-tetrachlorophenol in 44% of the samples (GM < LOQ). Comparison to previous cycles of GerES revealed substantially lower exposure to most of the chlorophenols in GerES V. Exposure levels found in Germany were comparatively low in contrast to North American results.

Hand dermatitis in adults referred for patch testing: Analysis of North American Contact Dermatitis Group Data, 2000 to 2016

Hand eczema (HE) is a heterogeneous and burdensome disorder. To characterize the clinical characteristics, etiologies and allergen relevance in adults with HE referred for patch testing. Retrospective analysis (2000-2016) of North American Contact Dermatitis Group data (n=37,113). Overall, 10,034 patients had HE, with differences of overlap between allergic contact, irritant contact, and atopic dermatitis. Allergic contact HE fluctuated, whereas atopic HE steadily increased, and irritant HE decreased over time. HE was associated with higher proportions of positive patch tests (67.5% vs 63.8%; χ2, P<.0001). The five most common clinically relevant allergens were methylisothiazolinone, nickel, formaldehyde, quaternium-15, and fragrance mix I. HE was associated with significantly higher odds of positive patch test reactions and clinical relevance in 13 and 16 of the 25 most common allergens, respectively, including preservatives, metals, topical medications, and rubber accelerators. No data on HE phenotype. HE in adults was associated with higher proportions of positive patch tests, with a heterogeneous profile of allergens. Patch testing remains an important tool in the evaluation of patients with HE.

Clinical and trichoscopic evaluation of trichloroacetic acid 35% vs phenol 88% peels in treatment of alopecia areata

Among alopecia areata (AA) treatments, contact irritants (anthralin) and topical immunotherapies (diphenylcyclopropenone) have been successfully used. Chemoexfoliation can potentially be utilized, acting as irritants and consecutively immunomodulators. Peels via therapeutic wounding provoke growth factors and cytokines that may induce hair regrowth. To evaluate and compare trichloroacetic acid (TCA) 35% and phenol 88% peels effectiveness and tolerability in patchy AA. This comparative, randomized, double-blind study included 20 patients with multifocal patchy AA. In each patient, 2 patches were selected and randomized into group I (20 patches: TCA 35%) and group II (20 patches: phenol 88%). A session was performed every 3weeks for 9weeks. Response was assessed by two blinded observers as regards percentage of clinical improvement, severity of alopecia tool (SALT), and trichoscopic scaled scores for dystrophic and terminal hairs, respectively. Patients were scheduled for follow-up visits over 6months past treatment cessation. A total of 19 patients completed the study and showed significant reduction in SALT score. TCA- and phenol-treated patches demonstrated significant improvement in the percentage of clinical improvement, trichoscopic scale of dystrophic and terminal hairs. However, TCA was superior to phenol as it showed significant more reduction in trichoscopic score of dystrophic hairs and significant higher increase in terminal hairs. Phenol yielded significant higher discomfort than TCA. No relapse was detected. Trichloroacetic acid 35% and phenol 88% peels can be considered effective therapeutic modalities for patchy AA. TCA 35% represents a treatment of choice in terms of the efficacy and tolerability.

Las defensas físico-químicas de las plantas y su efecto en la alimentación de los rumiantes

Las plantas son consumidas por diversos organismos, esta situación pone en riesgo su sobrevivencia, por ello han desarrollado mecanismos de defensa que evitan su ingesta. Por ejemplo, adaptaciones anatómicas, defensas químicas o metabolitos secundarios. Estos fitoquímicos inhiben el ataque de patógenos, provocan irritación al contacto, afectan los sistemas cutáneo, gastrointestinal, cardíaco y nervioso de los herbívoros o pueden provocar la muerte. Los rumiantes tienen adaptaciones mecánicas, fisiológicas y etológicas para evadir las defensas vegetales: rechazo, regulación y biotransformación. Desarrollaron adaptaciones anatomo-fisiológicas para albergar simbiontes microbianos para degradar celulosa y toxinas vegetales. Algunos metabolitos secundarios pueden tener efectos benéficos en alimentación o medicina animal, pero se requiere de mayor estudio sobre el tema.