Botanical Briefs: Contact Dermatitis Induced by Western Poison Ivy (Toxicodendron rydbergii).

"Leaves of three, leave it be" serves as an apt caution for avoiding poison ivy (Toxicodendron species) and its dermatitis-inducing sap. Toxicodendron contact dermatitis (TCD) poses a notable burden to the American health care system by accounting for half a million reported cases of allergic contact dermatitis (ACD) annually. Identifying and avoiding physical contact with the western poison ivy (Toxicodendron rydbergii) plant prevails as the chief method of preventing TCD. This article discusses common features of T rydbergii as well as clinical manifestations and treatment options following exposure to this allergenic plant.

Vortex-blending matrix solid-phase dispersion and UPLC-Q-TOF/MS were proposed to extract and examine the urushiols from Toxicodendron vernicifluum bark.

Toxicodendron vernicifluum bark has been used for many years as a component in foods and as a traditional herbal medication. Unfortunately, the presence of urushiols, which induce allergies, limits its application. This study used a vortex-blending matrix solid-phase dispersion microextraction technique to extract urushiols from Toxicodendron vernicifluum bark. HPLC was used to evaluate the amounts of the extracted urushiols (15:0, 15:1, 15:2, and 15:3). The modified magnetic adsorbent was prepared through an in situ coprecipitation method and characterized using a variety of techniques. The optimized extraction conditions are as follows: using magnetic Zeolite Socony Mobil-Five as an adsorbent, a 1:2 sample/adsorbent ratio, 2.5 min of vortex-blending time, 4 mL of 0.1% (V/V) trifluoroacetic acid-methanol as the elution solvent and 8 min of ultrasound time. There was good linearity and high repeatability in the method. Furthermore, the limits of detection for the urushiols ranged from 0.20 to 0.50 µg/mL. Under the optimized conditions, 50 compounds were identified by ultra high performance liquid chromatography and quadrupole time-of-flight mass spectrometry. These compounds included 8 phenolic acids, 9 monomeric urushiols, 11 urushiol dimers, 10 other components, and 11 flavonoids. The suggested approach, which has the advantages of few stages and high extraction efficiency over existing extraction procedures, is a potentially useful method for obtaining and evaluating urushiols in raw materials or extracts.

Herbarium specimens reveal century-long trait shifts in poison ivy due to anthropogenic CO2 emissions.

PREMISE: Previous experimental studies have shown that poison ivy (Toxicodendron radicans; Anacardicaceae) responds to elevated CO2 with increased leaf production, water-use efficiency, and toxicity (allergenic urushiol). However, long-term field data suggest no increase in poison ivy abundance over time. Using herbarium specimens, we examined whether poison ivy and other species shifted leaf traits under natural conditions with increasing atmospheric CO2 (pCO2 ) over the past century. METHODS: We measured stomatal density, leaf area, leaf N, leaf C:N, leaf carbon isotope discrimination (Δleaf ), and intrinsic water-use efficiency (iWUE) from 327 specimens collected from 1838 to 2020 across Pennsylvania. We compared poison ivy's responses to two evolutionarily related tree species, Toxicodendron vernix and Rhus typhina (Anacardiacae) and one ecological analog, Parthenocissus quinquefolia (Vitaceae), a common co-occurring liana. RESULTS: Stomatal density significantly decreased (P < 0.05) in poison ivy and the ecologically similar liana P. quinquefolia over the past century, but did not change in the related trees T. vernix and R. typhina. None of these species showed significant trends in changes in leaf N or C:N. Surprisingly, in poison ivy, but not the other species, Δleaf increased with increased pCO2 , corresponding to significant declines in iWUE over time. CONCLUSIONS: In contrast to the results of short-term experimental studies, iWUE decreased in poison ivy over the last century. Trait responses to pCO2 varied by species. Herbarium specimens suggest that realized long-term plant physiological responses to increased CO2 may not be reflected in short-term experimental growth studies, highlighting the value of collections.

Evaluation and Management of Toxicodendron Dermatitis in the Emergency Department: A Review of Current Practices.

Toxicodendron dermatitis is an underappreciated disease seen in the emergency department. Although self-limiting, symptoms can be distressing and can last for weeks if untreated, particularly with re-exposure. Continuing research has improved our understanding of specific inflammatory markers that are associated with exposure to urushiol-the compound responsible for Toxicodendron dermatitis-although consensus for treatment remains varied and poorly supported. Owing to the lack of recent primary literature on the topic, many providers rely on historical precedent, expert opinion, and personal experience when treating this disease. This article provides a narrative review of the literature currently available on the effects of urushiol on key molecular and cellular functions and the prevention and treatment of Toxicodendron dermatitis.

Chloroplast genome sequence of triploid Toxicodendron vernicifluum and comparative analyses with other lacquer chloroplast genomes.

BACKGROUND: Toxicodendron vernicifluum, belonging to the family Anacardiaceae, is an important commercial arbor species, which can provide us with the raw lacquer, an excellent adhesive and painting material used to make lacquer ware. Compared with diploid, triploid lacquer tree has a higher yield of raw lacquer and stronger resistance to stress. Triploid T. vernicifluum was a newly discovered natural triploid lacquer tree. However, the taxonomy of triploid T. vernicifluum has remained uncertain. Here, we sequenced and analyzed the complete chloroplast (cp) genome of triploid T. vernicifluum and compared it with related species of Toxicodendron genus based on chloroplast genome and SSR markers. RESULTS: The plastome of triploid T. vernicifluum is 158,221 bp in length, including a pair of inverted repeats (IRs) of 26,462 bp, separated by a large single-copy region of 86,951 bp and a small single-copy region of 18,346 bp. In total, 132 genes including 87 protein-coding genes, 37 tRNA genes and 8 rRNA genes were identified in the triploid T. vernicifluum. Among these, 16 genes were duplicated in the IR regions, 14 genes contain one intron, while three genes contain two introns. After nucleotide substitutions, seven small inversions were analyzed in the chloroplast genomes, eight hotspot regions were found, which could be useful molecular genetic markers for future population genetics. Phylogenetic analyses showed that triploid T. vernicifluum was a sister to T. vernicifluum cv. Dahongpao and T. vernicifluum cv. Hongpigaobachi. Moreover, phylogenetic clustering based on the SSR markers showed that all the samples of triploid T. vernicifluum, T. vernicifluum cv. Dahongpao and T. vernicifluum cv. Hongpigaobachi in one group, while the samples of T. vernicifluum and T. succedaneum in another group, which is consistent with the cp genome and morphological analysis. CONCLUSIONS: The current genomic datasets provide pivotal genetic resources to determine the phylogenetic relationships, variety identification, breeding and resource exploitation, and future genetic diversity-related studies of T. vernicifluum.

Relative quantification of phenolic compounds in exocarp-mesocarp and endocarp of sumac (Toxicodendron vernicifluum) combined with transcriptome analysis provides insights into glycosylation of flavonoids and biflavonoid biosynthesis.

The pericarp of fruit can be differentiated into endocarp, mesocarp, and exocarp. To explore the differences in gene expression and metabolites in different tissues of the pericarp, the fruits of sumac (Toxicodendron vernicifluum) were separated into endocarp and mesocarp-exocarp. The metabolites and transcriptome of exocarp-mesocarp and endocarp of Toxicodendron vernicifluum were analyzed by HPLC-QTOF-MS/MS and RNA sequencing, respectively. A total of 52 phenolic compounds were identified, including 3 phenylpropane derivatives, 10 urushiol compounds and 39 flavonoids. The exocarp-mesocarp contained more urushiol compounds and flavonoid glycosides while the endocarp contained more biflavonoids, such as rhusflavone and dihydromorelloflavone. The characteristic component of endocarp was rhusflavone and the characteristic component of exocarp-mesocarp was urushiol (triene). Most of the genes involved in flavonoid synthesis pathway were upregulated in endocarp compared with exocarp-mesocarp and positively correlated with the content of flavonoids. The candidate genes related to the synthesis of components of flavonoid glycosides and biflavonoids were screened. Metabolomic and transcriptomic analyses provide new insights into the synthesis and distribution of flavonoid glycosides and biflavonoids in the fruits of Toxicodendron vernicifluum.

Raw Lacquer Extract from Toxicodendron vernicifluum in Combination with ONC201 Enhances the Inhibitory Effects on Colorectal Cancer Cell Activity.

BACKGROUND: The purpose of the present research was to explore the therapeutic impact of raw lacquer extract from Toxicodendron vernicifluum on colorectal cancer cells and to investigate the outcome of raw lacquer extract and ONC201 co-treatment on the activity of colorectal cancer cells. METHODS: The cells of HCT116 were treated with raw lacquer extract, ONC201, or co-treatment. Subsequently, MTT, trypan blue staining, colony formation, annexin V/propidium iodide staining, wound healing, and transwell assays were performed to assess the effects of raw lacquer extract, ONC201 and the synthesis effect of co-treatment on cell activity, survival, proliferation, apoptosis, migration, and invasion in HCT116 cells. Western blotting and immunostaining assay were also performed to detect the expressions of tumor necrosis factor-related apoptosis-inducing ligand, death receptor-5, cleaved caspase-8, p-mTOR/mTOR, and p-S6K/S6K in cells. RESULTS: The results showed that ONC201 and raw lacquer extract had effective anti-cancer effects on HCT116 cells. ONC201 and raw lacquer extract treatment on colorectal cancer cells inhibited cell viability and growth, as well as induced cell apoptosis and cell death of HCT116. The migration and invasion of HCT116 cells were also inhibited. Significantly, raw lacquer extract and ONC201 cotreatment further enhanced the anti-colorectal cancer cell activity in HCT116 cells. Western blotting and immunostaining assay showed that raw lacquer extract in combination with ONC201 induced tumor necrosis factor-related apoptosis-inducing ligand/death receptor-5 expression activation, inhibited the expression of cleaved caspase-8/procaspase-8, and reduced the expression of p-mTOR/mTOR and p-S6K/S6K. CONCLUSION: These results indicated that raw lacquer extract in combination with ONC201 enhanced the inhibitory effects on colorectal cancer cell activity.

Safety assessment of oil extracted from lacquer (Toxicodendron vernicifluum (Stokes) F.A. Barkley) seed: acute and subchronic toxicity studies in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Toxicodendron vernicifluum (Stokes) F.A. Barkley (RVS) is an economic tree species and widely distributed in East Asia. Wood parts and raw lacquers of RVS have been used in coatings, herbal medicines or food supplements, and the leaves, flowers, roots, and fruits of RVS are also widely used in medicine traditionally. Lacquer seed oil (LSO) has potential health benefits and has not previously been evaluated for safety. AIM OF THE STUDY: The aim of the present study was to investigate the toxicological potential of LSO by acute and subchronic toxicity tests. MATERIALS AND METHODS: The characterization of fatty acids of the LSO was carried out by gas chromatography. In the acute toxicity study, LSO was administered at single doses of 5000 or 10000 mg/kg by oral gavage. The subchronic toxicity study was conducted by daily oral administration of LSO at doses of 1250, 2500 and 5000 mg/kg/day for 30 consecutive days. The animals were evaluated for clinical observations, body weight, organ weight, feed consumption, biochemical and hematological parameters, and liver, lung, and kidney histology. RESULTS: There were no mortality and toxic changes were observed in acute toxicity study. The results of subchronic toxicity showed no toxicologically significant changes in clinical observations, body weight, organ weight, biochemical or hematological parameters. Histopathologic results indicated slight hepatic steatosis and inflammatory infiltration in the rats of 5000 mg/kg/day LSO treated group. However, the histopathologic observation was not confirmed by hepatic biochemical analysis. CONCLUSIONS: These results suggested that the LD50 of LSO is over 10000 mg/kg and LSO is non-toxic for SD rats in acute toxicity study. The no observed adverse effect level (NOAEL) of LSO in rats is considered to be 5000 mg/kg/day, and liver is the potential target organ of LSO for 30-day subchronic toxicity study.

Verniciflavanol A, a profisetinidin-type-4-arylflavan-3-ol from toxicodendron vernicifluum protects SH-SY5Y cells against H2O2-Induced oxidative stress.

Eleven undescribed derivatives of flavan, including flavan-3,4-diols vernicinosides A-H and profisetinidin-type-4-arylflavan-3-ols verniciflavanols A-C, together with eight known compounds were purified from the heartwood of Toxicodendron vernicifluum. The chemical structures of the undescribed compounds were characterized by spectroscopic data interpretation, including NMR (1H and 13C NMR HSQC and HMBC) and HRESIMS analysis. CD data analysis was conducted to assign the absolute configurations of the undescribed compounds and the active compound verniciflavanol A was also confirmed by ECD experiment. The absolute configuration of the sugar moiety was identified by GC analysis of chiral derivatives in the hydrolysate. MTT assay was applied to test these compounds against H2O2-induced oxidative stress in human neuroblastoma SH-SY5Y cells. Results found that verniciflavanol A demonstrated the best potential in protecting SH-SY5Y cells against H2O2-induced oxidative stress by inhibiting cell apoptosis and attenuate reactive oxygen species (ROS) level and mitochondrial dysfunction. And the underlying mechanism was confirmed to be associated with Nrf2-antioxidant response element signaling and IL-6 cell survival pathways.

Identification of Reliable Reference Genes under Different Stresses and in Different Tissues of Toxicodendron succedaneum.

Toxicodendron succedaneum (L.) Kuntze (T. succedaneum) is an economic tree species that produces urushiol and urushi wax, and it is of great value in industry and medicine. However, the stability of reference genes (RGs) has not been systematically reported in T. succedaneum to date. In this study, the expression of 10 candidate RGs was analyzed by RT-qPCR in different tissues (roots, stems, leaves), stress treatments (high/low temperature, drought), and hormone stimulation (jasmonic acid, JA). Then, the stability ranking of 10 candidate genes was evaluated by ∆Ct analysis and three software programs: geNorm, NormFinder, and BestKeeper. Finally, RefFinder was used to comprehensively analyze the expression stability of 10 candidate genes. The comprehensive analysis showed that TsRG05/06, TsRG01/06, and TsRG03/ACT were stable under high/low-temperature stress, drought stress, and JA treatment, respectively. TsRG03 and ACT had stable expression in different tissues. While the TsRG03 and ACT were recommended as the suitable RGs for T. succedaneum in all samples. Meanwhile, UBQ was the least suitable as a reference gene for T. succedaneum. In addition, the results of geNorm showed that the combination of two stable RGs could make the results of gene expression more accurate. These results provide alternative RGs for the study of gene function, correction, and normalization of target gene expression and directed molecular breeding in T. succedaneum.

Bioactive abietane diterpenes and benzofuran neolignans from the resins of Toxicodendron vernicifluum.

Six new compounds (1-6), including two abietane diterpenes (1,2) and four benzofuran neolignans (3-6), along with five known compounds (7-11) were isolated and identified through phytochemical investigation on the resins of Toxicodendron vernicifluum (Toxicodendri Resina). The structures of the new compounds were fully elucidated by their 1D and 2D NMR, HRESIMS, UV, and IR spectroscopic data analyses. The absolute configurations of 1-4 were deduced by comparison of the experimental and calculated electronic circular dichroism (ECD) data. The inhibitory effects of the isolates on myocardial fibrosis induced by TGF-ß were examined, and compounds 1, 5, and 7-10 showed the anti-proliferation of myocardial fibroblasts at the concentrations of 10-40 µM in a dose-dependent manner.

Poison Ivy Dermatitis Treatment Patterns and Utilization: A Retrospective Claims-based Analysis.

INTRODUCTION: Poison ivy (toxicodendron) dermatitis (TD) resulting from contact with poison ivy, oak, or sumac is a common form of allergic contact dermatitis that impacts millions of people in the United State every year and results in an estimated 43,000 emergency department (ED) visits annually. Our objective in this study was to evaluate whether healthcare utilization outcomes are impacted by prescription practices of systemic corticosteroids. METHODS: We used a health claims database from 2017-2018 of those treated for TD. Descriptive statistics and logistics regression models were used to characterize trends. RESULTS: We included in this analysis 115,885 claims from 108,111 unique individuals (93.29%) with 7,774 (6.71%) return claims within 28 days. Of the return claims, 470 (6.05%) were to the ED. Emergency clinicians offered no oral corticosteroid prescription 5.27% (n = 3,194) of the time; 3276 (86.26%) prescriptions were for a duration of 1-13 days, 410 (10.80%) were for 14-20 days, and 112 (2.95%) were for >21 days. Further, we found that shorter duration oral corticosteroids (odds ratio [OR] 1.30; 95% confidence interval 1.17-1.44; P <0.001) and initial treatment for TD at the ED compared to primary care clinicians (OR 0.87 [0.80, 0.96]; P <0.001) and other non-dermatologists (OR 0.89 [0.80, 0.98]; P = 0.01) places patients at an increased risk for return visits with healthcare clinicians when controlling for drug group, duration of treatment, and initial treatment location. CONCLUSION: Despite recommendations to treat TD with oral steroids for at least 14 days, most emergency clinicians offered this treatment for shorter durations and was associated with return visits. Emergency clinicians should consider treatment of two to three weeks when providing systemic steroid coverage when there are no limiting contraindications, especially as patients who present to the ED may do so with more severe disease. Additional education may be needed on appropriate treatment pathways for TD to reduce healthcare utilization associated with undertreatment.

Methods to promote seed germination in the lacquer tree, Toxicodendron vernicifluum (Stokes) F.A. Barkley.

The lacquer tree, Toxicodendron vernicifluum, is a common industrial crop in East Asia. However, T. vernicifluum seeds are extremely difficult to germinate, which poses a major obstacle to establishing seedlings for sap production. In this study, we examined the germination properties of T. vernicifluum seeds in order to establish an inexpensive and effective method to promote seed germination. The seeds are covered with a hard endocarp, which we degrade using conventional sulfuric acid-based methods. Although sulfuric acid was effective in promoting seed germination, the germination rate was less than 5%. In addition to treatment with sulfuric acid, co-treatment with cold temperatures or the phytohormone gibberellic acid increased the germination rate to 22-35%. Seed viability analysis combined with specific gravity-based seed selection revealed that more than half of the seeds housed embryos that were incapable of germination. In additions, specific gravity-based seed selection aided in the selection of seeds capable of germination and improved the germination rate to approximately 47%. Taken together, our results suggest that the low germination rate of T. vernicifluum seeds is due to deep seed dormancy-which is controlled by physical and physiological mechanisms-and low embryo viability. To improve the germination rate of T. vernicifluum seeds, we propose an effective method whereby seeds with good germination capacity are selected based on specific gravity, following which their physiological dormancy is inactivated through cold pretreatment.

Isolation and Identification of Fisetin: An Antioxidative Compound Obtained from Rhus verniciflua Seeds.

The goal of this study was to provide basic data for the development of functional food and health materials for Rhus verniciflua (R. verniciflua) seeds. We investigated an antioxidative compound obtained from these seeds. Solvent fractionation was carried out on a 50%-ethanol extract of the seeds. The DPPH and ABTS radical-scavenging activity and superoxide dismutase (SOD) activity were measured, and high antioxidant activity was seen in the ethyl acetate fraction. The antioxidant compounds in the ethyl acetate fraction were isolated using silica-gel column chromatography by adjusting the solvent between chloroform and methanol. Fraction numbers 2-7 showed activity of more than 50%. Next, primary column chromatography was used to mix and concentrate the fractions that demonstrated antioxidant activity. The fractions were then subjected to secondary column chromatography to obtain subfraction 4, which showed high antioxidant activity. The separation of subfraction 4 was then performed using high-performance liquid chromatography (HPLC). Three peaks were identified and peak number 2 was judged to be the primary antioxidative compound, which was then isolated by pure separation. Finally, the purified subfraction peak number 2 was identified as a fisetin compound by liquid chromatography-mass spectrometry (LC-MS), nuclear magnetic resonance (NMR), and HPLC.

Death After Poison Ivy Smoke Inhalation.

ABSTRACT: Urushiol, the active antigen in poison ivy ( Toxicodendron radicans ), is frequently associated with type I and type III hypersensitivity reactions. These reactions most often result in cutaneous symptoms that vary in severity and may at times require medical interventions. Injuries involving other body systems associated with urushiol exposure are far less common. Here, we present 2 unrelated cases of urushiol respiratory exposure status after burning of poison ivy that resulted in cardiopulmonary arrest and ultimately death. In both cases, the history, circumstances, and autopsy findings are consistent with urushiol smoke inhalation having either caused or contributed to death. The cases are unique in that they represent the first cases of death related to poison ivy smoke exposure. Clinicians and forensic pathologists should be aware of the fact that urushiol smoke exposure may lead to morbidity and mortality.

Black-Spot Toxicodendron Dermatitis With Varied Presentation.

This article describes the clinical presentation, differential diagnosis, and treatment of 2 unrelated cases with different presentations of black-spot Toxicodendron dermatitis. In the first case, a healthy 7-y-old male presented with a rash consisting of black dots with localized surrounding erythema on the left arm. The rash then progressed to a vesicular, pinpoint, raised rash spreading to the face, arms, and neck. In the second case, a 4-y-old male presented with non-pruritic, black, flat, non-erythematous lesions that did not progress. This patient's older sibling had been diagnosed with poison ivy 1 wk prior, and they attended the same child care where the poison ivy was thought to be acquired. In both cases, diagnosis of black-spot Toxicodendron dermatitis was made. The black spot of Toxicodendron dermatitis is caused by urushiol oxidation on exposure to air. The subject may or may not go on to develop allergic contact dermatitis after the exposure. Diagnosis of this dermatitis is made on clinical presentation, with careful consideration of history, distribution, and lesion morphology. When allergic dermatitis does develop as in the first case, systemic treatment with oral steroids is recommended. In both of these cases the black dots completely resolved in 2 to 3 wk. Dermatologic referral for dermoscopy and biopsy may be necessary if the dermatosis does not resolve as anticipated.

Novel Flavan-3,4-diol vernicidin B from Toxicodendron Vernicifluum (Anacardiaceae) as potent antioxidant via IL-6/Nrf2 cross-talks pathways.

BACKGROUND: Oxidative stress is considered to be a pathological factor of various neurodegenerative diseases. Studies have confirmed the antioxidant activity of T. vernicifluum. However, the main active components responsible for antioxidant activity remain unknown. OBJECTIVE: The aim of this study is to explore the activities of vernicidin B on oxidative stress injury induced by H2O2 in SH-SY5Y cells, and the underlying mechanism of vernicidin B in oxidative stress-related neurological diseases is further discussed. METHODS: Various separation methods were used to isolate and identify the compounds in an EtOAc extract of T. vernicifluum. The structures of the isolates were clarified by HR-TOF-MS and 1D/2D NMR data and compared with findings in previous literature. The MTT assay was used to evaluate the potential antioxidant activity of the isolated flavonoids. The apoptosis rate, mitochondrial reactive oxygen species (ROS) level and mitochondrial potential were measured by flow cytometry and fluorescence microscope. The levels of related proteins were detected by Western blotting. RESULTS: Four new flavan-3,4-diols (1-4, vernicidins A-D) and 11 known flavonoids (5-15) were purified from the EtOAc extract of T. vernicifluum. Among these compounds, vernicidin B showed the most promising potential for protecting SH-SY5Y cells from H2O2-induced oxidative stress. Moreover, pretreatment with vernicidin B decreased ROS production and mitochondrial membrane potential and significantly attenuated H2O2-induced apoptosis in a dose-dependent manner. Mechanistically, the antioxidant stress activities of vernicidin B were confirmed to be related to the IL-6/Nrf2 cross-talks pathway and its downstream pathways, including PI3K/Akt/mToR-Gsk3ß, JAK2/STAT3 and MAPKs. CONCLUSIONS: Our findings suggested that vernicidin B can improve the oxidative stress injury induced by H2O2 through IL-6/Nrf2 cross-talks pathway, indicating that it may be a potential candidate drug for the treatment of oxidative stress-related neurodegenerative diseases.

Botanical Briefs: Toxicodendron Dermatitis.

Toxicodendron dermatitis is a type IV hypersensitivity reaction resulting from exposure to urushiol found in poison ivy, poison oak, and poison sumac. The dermatitis presents as a pruritic erythematous rash with vesicles and bullae in areas that were in contact with the plant. Symptoms present after 24 to 48 hours and can be managed with a variety of treatments, depending on severity. Avoidance is the principal way to prevent Toxicodendron dermatitis, highlighting the importance of educating patients on identification of plants.

Contact Allergy Induced by Mango (Mangifera indica): A Relevant Topic?

INTRODUCTION: The most common clinical manifestation of mango allergy is contact dermatitis, which can be localized or systemic. The sensitising substances that have long been suspected are alk(en)yl catechols and/or alk(en)yl resorcinols. METHODS: We reviewed the original articles published on Pubmed, Embase and Cochrane Library before 15 September 2021, on the topic of contact allergy induced by mango and we synthesized the key data. RESULTS: We found 12 case reports and four case series, with a total of 37 patients. Only seven of these cases were reported in patients from mango-cultivating countries, the other 30 were from countries where mango cultivation does not occur, and 26 were also from countries where poison ivy/oak are commonly found. We found that contact dermatitis may occur on the first exposure to mango due to previous sensitisation to urushiol-containing plants. The diagnosis was confirmed by patch testing in some of the cases. There was great heterogeneity between the reagents used. CONCLUSION: Mango fruit is frequently consumed, but mango induced contact dermatitis, the main hypersensitivity reaction induced by mango, is rare. Further data is necessary for a better understanding of sensitising substances and, consecutively, standardization of patch test reagents.