Search Results (54)

Manchineel dermatitis, caused by the sap of the manchineel tree native to the coastlands of the Caribbean, West Africa, and Central America, has received limited attention in the literature despite significant morbidity. The toxic sap causes a burning, blistering rash and conjunctivitis, while ingestion of the fruit may lead to oropharyngeal pain, hemodynamic instability, and gastrointestinal distress. Tourists unfamiliar with the manchineel tree may be exposed through exposure to the tree’s sap, contaminated rainwater, or ingestion of the apple-like fruit. We herein present a case of a patient who experienced prolonged symptoms of manchineel toxicity after ingestion of the manchineel fruit for several weeks. Antihistamines, corticosteroids, and a PPI were ineffective. The symptoms eventually resolved after discarding clothing and towels that had come in contact with the tree, raising the possibility that toxins may linger on fabrics. Travellers to regions in the Caribbean or Central America are at particular risk for toxicity from the Manchineel tree if unfamiliar with the associated dangers and should be counselled to avoid contact with the tree or ingesting any unfamiliar fruit on the ground. When exposures do occur, it may be reasonable to dispose of potentially contaminated fabrics to avoid recurrent exposures, particularly if recurrent symptoms are observed, as in our patient. We further contextualize manchineel toxicity within a comparative review of select tropical foodborne intoxications of plant origin (ackee, lychee, cassava, papain) and marine origin (ciguatera, scombroid, neurotoxic and diarrhetic shellfish poisonings, tetrodotoxin), distinguishing manchineel’s local irritant mechanism from the systemic toxidromes of these comparators and underscoring the absence of a specific antidote. Full article

Contact dermatitis (CD) is one of the most common occupational skin diseases worldwide, and patch tests are used to identify allergic contact dermatitis (ACD). Half of the cases were negative for patch tests (non-ACD). In our study, we aim to analyze patch test negativity in different occupational groups from the Triveneto (northeast Italy) Patch Test Database and to identify associated demographic and exposure-related factors. Data from 31,948 patients evaluated for suspected ACD between 1997 and 2023 were analyzed. All participants underwent clinical examination, completed a standardized questionnaire, and underwent patch testing. Occupational categories and anatomical sites were aggregated into broader groups and analyzed with multivariable logistic regression models. Among 31,948 patients with CD, 43.4% had negative patch test results. The mean age was 43.8 ± 17.2 years, with a predominance of female patients (66.7%). Hands were the most affected body site (30.9%), with lower prevalence of patch test negativity (OR 0.936; 95% CI 0.892–0.981). Non-ACD was more frequent among non-workers as students (OR 1.380; 95% CI 1.192–1.597) and in occupational groups involved in wet work, detergent use, mechanical friction, and exposure to irritating substances such as mechanics (OR 1.152; 95%CI 1.018–1.204) and cooks with hand dermatitis (OR 1.784; 95%CI 1.936–3.071). These findings highlight the importance of non-ACD, the need for better prevention strategies, improved skin protection practices, and early recognition of irritant exposure in the workplace. Full article

Chronic hand eczema (CHE) is a persistent and relapsing inflammatory dermatosis characterized by substantial functional impairment, psychosocial distress, and occupational disability. Although epidemiologically common and clinically burdensome, CHE has long suffered from nosological ambiguity, frequently interpreted as a localized manifestation of atopic dermatitis, psoriasis, allergic contact dermatitis, or cumulative irritant dermatitis. The recent regulatory approval of topical delgocitinib, a pan-Janus kinase (JAK) inhibitor specifically indicated for moderate-to-severe CHE inadequately controlled by topical corticosteroids, has reshaped both therapeutic strategy and conceptual framing of the disease. The introduction of a targeted therapy dedicated to CHE has reinforced its clinical identity while simultaneously highlighting its internal biological heterogeneity. Beneath the umbrella term “chronic hand eczema” lie distinct phenotypes characterized by variable barrier dysfunction, immune polarization, and environmental interaction. This review integrates current knowledge on epidemiology, pathophysiology, diagnostic stratification, therapeutic algorithms, phase III registrative evidence, emerging real-world data, and the central role of barrier restoration. Particular attention is devoted to the hand as a specialized barrier organ and to the interplay between inflammation and epidermal structural integrity. In the era of targeted therapy, precise diagnostic framing and barrier-oriented management are indispensable to optimize outcomes. Full article

Background: Dermatitis affecting the earlobe is a highly frequent clinical presentation, predominantly attributed to Allergic Contact Dermatitis (ACD) caused by metallic ions like nickel from earrings. However, a significant subset of patients presents with recurrent eczematous lesions highly suggestive of ACD but with inconclusive or negative patch test results, posing a profound diagnostic and therapeutic dilemma. Objective: This comprehensive review critically evaluates the differential diagnosis of earlobe eczema in the context of negative patch tests. Drawing from a representative case of a 30-year-old female with recurrent earlobe eczema and a strong family history of psoriasis, we explore alternative non-immunological and endogenous mechanisms, specifically Irritant Contact Dermatitis (ICD) and the Koebner Phenomenon on a background of Psoriatic Diathesis. Methods: We performed an extensive review of the current literature focusing on the epidemiology and pathogenesis of metal ACD, non-allergic mechanisms of jewelry-induced dermatitis (ICD), the molecular basis of the Koebner phenomenon, and the clinical overlap between eczema and psoriasis (Eczematous Psoriasis). Results: The localized nature of the inflammation, coupled with the absence of generalized nickel sensitivity, strongly suggests that the mechanical and occlusive trauma from earrings can induce a purely irritant reaction. Crucially, the presence of a familial psoriatic diathesis supports the hypothesis that this local irritation acts as a Koebner phenomenon trigger, leading to an eczematous manifestation of an underlying psoriatic tendency. Conclusions: Not all recurrent eczematous lesions at common contact sites are caused by ACD. Clinicians must adopt an integrated diagnostic approach, factoring in personal and family history alongside patch test results, to differentiate true allergy from ICD and the Koebner phenomenon. This nuanced perspective is vital for providing appropriate counseling (strict jewelry avoidance) and targeted, often steroid-sparing, management (e.g., topical calcineurin inhibitors) for a durable therapeutic outcome. Full article

Occupational dermatoses represent a significant challenge across numerous industries. Therefore, occupational skin protection creams are frequently used as a preventative measure, yet their efficacy, particularly against hydrophobic working materials, remains inconclusive. This review provides an overview of the current knowledge concerning the mechanisms by which skin protection creams support skin barrier function, as well as the limitations of available testing methods. Current evaluation methods range from in vitro assays to ex vivo and in vivo models, each possessing distinct advantages and disadvantages. While several clinical studies demonstrate effectiveness against hydrophilic irritants, standardized and ethically viable methods for assessing protection against hydrophobic substances are lacking. Future research should focus on the development and validation of improved in vitro and ex vivo models, coupled with enhanced workplace simulation techniques, to facilitate a more accurate translation of laboratory findings to real-world occupational settings. Consistent and reliable testing is essential to ensure continued efficacy of these products in light of evolving regulatory landscapes. Full article

Background: Contact dermatitis (CD) is a prevalent inflammatory skin condition, with diagnostic challenges in distinguishing allergic (ACD) from irritant contact dermatitis (ICD). This study aimed to explore cholesterol-derived biomarkers as potential diagnostic tools. As cholesterol derivatives play key roles in skin barrier integrity and inflammation, they are promising candidates for assessing skin barrier disruption in CD. Methods: Stratum corneum samples were collected by tape stripping from experimentally induced and chronic lesions, as well as healthy non-lesional skin. Biomarkers Cholesterol Sulfate (Chol-Sulf), Cholesterol Glucosyl (Chol-Glc) and their ratio were quantified. Data were analyzed using ANOVA, Pearson’s correlation, logistic regression and ROC curves. Results: Chol-Glc and the Chol-Glc/Chol-Sulf ratio differed significantly across the diagnostic groups, while Chol-Sulf did not. Logistic regression and ROC analyses revealed a limited standalone diagnostic accuracy for the individual biomarkers (all AUC < 0.6). Conclusions: Chol-Glc and the ratio exhibit disease-specific patterns relevant for subtype discrimination. Although insufficient as independent diagnostic tools, these markers may contribute to future multivariate diagnostic models for CD diagnosis. Full article

Contact dermatitis is a common inflammatory skin disorder characterized by erythematous and pruritic lesions caused by irritant exposure. Ohwia caudata, a traditional medicinal plant, possesses anti-inflammatory and antioxidant properties, but its dermatoprotective potential remains unclear. To investigate the protective effects and mechanisms of Ohwia caudata leaves’ hydroethanolic extract in a murine model of TPA-induced contact dermatitis. Major phytochemicals in Ohwia caudata extract were identified by HPLC–MS. SKH1/J hairless mice were topically treated with Ohwia caudata extract following TPA stimulation. Skin barrier function was assessed by transepidermal water loss and hydration. Inflammatory (IL-6, TNF-α, TGF-β), antioxidant (SIRT1, Nrf2, HO-1), and ERK-related (p-ERK, eIF2α, ATF-4, CHOP) proteins were analyzed by immunoblotting and immunofluorescence. HPLC–MS revealed harmine, swertisin, isoliquiritigenin, eupatilin, 3′,4′-dimethoxyflavone, and nerolidol as key constituents. The extract significantly reduced transepidermal water loss and enhanced hydration, indicating improved barrier integrity. It downregulated IL-6 and TNF-α while restoring TGF-β expression. ERK and downstream eIF2α/ATF-4/CHOP activation were suppressed, whereas SIRT1/Nrf2/HO-1 antioxidant signaling was enhanced. Ohwia caudata leaves hydroethanolic extract protects against TPA-induced dermatitis by improving skin barrier function, suppressing inflammation, and activating antioxidant defense, supporting its potential as a natural therapeutic for inflammatory skin diseases. Full article

Contact dermatitis is a common inflammatory skin disorder triggered by exposure to allergens or irritants and characterized by erythema, swelling, and immune cell infiltration. In this study, we investigated the anti-inflammatory effects of exosome-like nanovesicles derived from Peucedanum japonicum Thunb. (PjELNs) using a 2,4,6-trinitrochlorobenzene (TNCB)-induced mouse model of contact dermatitis. Intraperitoneal administration of PjELNs markedly reduced ear swelling and histopathological damage and decreased infiltration of inflammatory immune cells, particularly neutrophils. Moreover, PjELNs downregulated the expression of key pro-inflammatory cytokines, including CXCL2 and IL-1β, in the affected tissue. These findings indicate that PjELNs alleviate contact dermatitis-associated inflammation and suggest their potential as a novel plant-derived therapeutic modality for inflammatory skin diseases. Full article

Contact dermatitis (CD) is a common inflammatory skin condition with irritant etiology or a delayed-type hypersensitivity called allergic contact dermatitis (ACD). Contact hypersensitivity (CHS) is a widely used rodent model of ACD and similarly consists of two phases: sensitization and elicitation. To trigger CHS, low-molecular-weight haptens, such as DNFB or TNCB, are commonly applied. However, the characterization of the induced immune response remains incomplete. Our aim was to characterize the immune response after first and repeated exposures to model haptens. First exposure to DNFB or TNCB led to significant ear swelling, with DNFB causing a more pronounced effect. DNFB enhanced neutrophil infiltration, whereas TNCB led to macrophage, dendritic cell, and helper T cell accumulation. Repeated DNFB exposure did not aggravate edema significantly, while TNCB re-exposure enhanced edema formation and induced neutrophil granulocyte, dendritic cell, and helper and cytotoxic T cell accumulation. Our results demonstrate that a hapten-specific immune response is induced during both phases of CHS. A detailed understanding of allergen-specific immune responses is crucial for the appropriate selection of the model and for gaining deeper insight into the mechanisms of inflammatory skin diseases. These findings may contribute to the targeted selection of haptens. Full article

The potent sensitizer PPD is considered a key sensitizer in hair dye contact allergy. Modification of its molecular structure to 2-methoxymethyl-p-phenylenediamine (ME-PPD) reduces its skin sensitizing potency. We investigated the usage, behavior, and tolerance profile of ME-PPD-containing professional hair color products in a specifically tailored proactive market surveillance program in hairdresser salons across 5 countries. Hairdressers completed record cards for their clients, which were evaluated at the end of the program. 497 individuals received in total 2461 hair color treatments with ME-PPD-containing hair color. Feedback on compatibility was provided for 194 individuals: 6 individuals reported intolerance reactions, which were assessed as likely allergic contact dermatitis (2), likely irritation (2), or were unassessable (2); none of these reactions were severe or serious. Mild discomfort was reported by 46 individuals, while 142 individuals explicitly reported good tolerance to the ME-PPD-containing hair color. A total of 27 individuals applied ME-PPD-containing hair color more than 15 times (long-term tolerability). The study confirms good tolerability of ME-PPD-containing hair color. This is consistent with the primary prevention benefit of ME-PPD in terms of significantly reduced risk of skin sensitization induction and the reduced severity of elicitation reactions for all hair dye users. Full article

Background/Objectives: Dermatitis is frequently treated with dexamethasone cutaneous application, which causes adverse effects mainly when it is chronically administered. Sesamol is a phytochemical compound known for its anti-inflammatory activity and low toxicity. Therefore, this study reports the optimization of a guar gum hydrogel with enhanced physicochemical and microbiological stability, providing an effective dosage form for topical application of sesamol nanocapsules to treat irritant contact dermatitis. Methods: Nano-based hydrogel containing 1 mg/g sesamol was prepared by adding the nanocapsule suspension to form a 2.5% (w/v) guar gum dispersion. Dynamic rheological analysis indicates that the formulations exhibit a non-Newtonian flow with pseudoplastic behavior. Hydrogels were evaluated by Fourier-transformed infrared (FTIR) spectroscopy, and, following spectrum acquisition, an unsupervised chemometrics model was developed to identify crucial variables. Additionally, the physicochemical and microbiological stability of the hydrogel was evaluated over a 60-day period. Results: ATR-FTIR spectra of all hydrogels evaluated are very similar after preparation and 60 days of storage. However, it showed a slight increase in average diameter and PDI and decreased pH values after 60 days. Microbiological assessment demonstrated that the hydrogel met the requirements for the microbial count over 60 days. The dermatitis model was induced by repeated applications of croton oil in the right ears of mice. The effectiveness of the hydrogels was evaluated by assessing ear edema and migration of polymorphonuclear cells. The nano-based hydrogel exhibited anti-inflammatory properties similar to those of dexamethasone. Conclusions: Therefore, the nano-based hydrogel containing sesamol exhibits therapeutic potential for treating cutaneous inflammatory diseases. Full article

The barrel jellyfish (Rhizostoma pulmo), like other cnidarians, shows cnidocytes containing cnidae, responsible for the jellyfish’s stinging properties. The sting of R. pulmo can cause contact dermatitis or urticaria and even systemic symptoms. Recent studies have identified stinging-cell structures in the mucous secretion released in the water column by Cassiopea xamachana, belonging to the same order as R. pulmo. The present paper verifies the release of stinging-cell structures in the water by R. pulmo and reports the case of two 17-year-old adolescents (one male and one female) who were affected by epidermal rashes consistent with the irritating sensations of stinging water. The reaction happened twice in the Ionian Sea; the patients were in proximity to R. pulmo but, on both occasions, there had been absolutely no direct contact with the jellyfish’s tentacles. To test the hypothesis of stinging water caused by R. pulmo, samples of sea water and mucous harvested in close proximity to a living jellyfish were taken and analyzed under a microscope at different magnifications. The microscopic analysis showed the presence of free and aggregated nematocysts in both the samples of water and mucous. It is likely that the free and aggregated nematocysts observed were discharged in the water by the jellyfish and were dispersed by water currents that led them to come into contact with the patients’ skin. At present, it is not known what predisposes humans to the perception of stinging water, and it is reasonable to affirm that caution should be advised for people with an allergic history when entering the water in the presence of jellyfish. Further investigations are required to better understand both the pathophysiological pathways underlying the stinging water phenomenon and the minimum concentration of urticating elements that is able to trigger the onset of stinging water. Full article

(1): Background: This study aimed to evaluate the concentrations of four proteins for allergic patch testing (APT) in dogs, assessing sensitivity (SE), specificity (SP), negative predictive value (NPV), positive predictive value (PPV), reactions to adhesives/containers, and the safety of APT with food proteins in dogs. (2) Methods: For evaluation, 43 dogs were screened and divided into two groups: Group 1 consisted of 20 healthy dogs, and Group 2 included 23 dogs with canine atopic dermatitis (AD). Group 1 underwent allergic patch testing (APT) with beef, pork, chicken, and soy proteins at four different concentrations (100 mg, 250 mg, 500 mg, 1000 mg/0.2 mL). Of the 23 dogs included in Group 2, four did not undergo the elimination diet and were excluded, leaving 17 dogs in the study. They underwent an elimination diet (ED) and were evaluated using the pruritus visual analog scale (pVAS) and lesion scores (CADESI-4) before and after the ED (days 0 and 45). After the ED, Group 2 was subjected to APT (using the same proteins and concentrations as Group 1) and an oral provocation test (OPT) with the proteins used in the APT. The results of the OPT were used to assess the accuracy of the APT. (3) Results: In Group 1, one dog reacted to the APT. In Group 2, after 45 days of ED, of the 17 dogs included, 13 showed a reduction in pVAS and CADESI-4 scores (p < 0.05) and nine an improvement considered good to excellent. Of these, two showed irritant contact reactions to the APT chambers and were excluded, leaving 11 dogs that were reactive to APT, and the OPT increased pruritus (p < 0.05). Accuracy: Beef and chicken proteins at concentrations of 500 and 1000 mg/0.2 mL, and soy protein at 1000 mg/0.2 mL, achieved 100% SE, SP, PPV, and NPV. Pork protein at 1000 mg/0.2 mL achieved 100% SE, 83% SP, 83% PPV, and 100% NPV. (4) Conclusions: APT with beef and chicken proteins at 500 mg and 1000 mg/0.2 mL and soy protein at 1000 mg/0.2 mL, based on the results of this study, can be recommended for diagnosing adverse food reactions in dogs with AD. Full article

Androgenetic alopecia is the most common cause of hair loss for women and men. Current treatments for androgenetic alopecia, such as those based on drugs like Minoxidil, Finasteride, or Dutasteride, have been associated with a variety of side effects, such as irritation, contact dermatitis, scalp pruritus, burning, etc. In this regard, plant extracts have emerged as promising alternatives to available chemical-based treatments for androgenetic alopecia given their efficacy, customer acceptability, and potentially minimized side effects. In this study, we evaluated the efficacy of Kyoh^®, an extract from rocket leaves, as a treatment to improve the signs of androgenetic alopecia. We found that Kyoh^® contained 2.1% total flavonoids, with kaempferol, quercetin, and isorhamnetin diglucosides being the most abundant. Additionally, Kyoh^® showed a stimulating effect on the growth of human dermal follicle papilla cells in laboratory conditions. Most importantly, Kyoh^® enhanced the gene expression of the hair growth-associated growth factors VEGF (Vascular Endothelial Growth Factor) and FGF7 (Fibroblast Growth Factor 7). Specifically, VEGF expression increased by 60.7% after 4 h and 267.3% after 24 h, while FGF7 expression increased by 50.3% after 4 h and 244.3% after 24 h, indicating both a rapid induction of gene expression and a sustained effect lasting at least one day. Moreover, Kyoh^® increased the gene expression of NRF2 (Nuclear factor erythroid 2-related factor 2) by 71.2%, which encodes for a protein participating in the antioxidant response. Overall, our study shows that flavonol-rich rocket extract (Kyoh^®) is a promising treatment for promoting hair growth, demonstrated by its proliferation-promoting effect, potential antioxidant priming, and induction of the expression of growth factors associated with hair growth and health. Full article

Healthcare workers (HCWs) are frequently exposed to a variety of chemical agents, which can result in the development of allergic or irritant contact dermatitis. The present study aimed to assess the prevalence of skin sensitization among HCWs who presented with symptoms of contact dermatitis, considering both occupational and non-occupational risk factors. The study population comprised 127 HCWs who attended routine occupational health surveillance at the Tor Vergata Teaching Hospital in Rome between November 2023 and May 2024. A structured dermatitis questionnaire and patch testing were administered to the participants. Demographic and lifestyle data, including information on occupation, night shift work, smoking habits, and body mass index (BMI), were collected. Patch test positivity was observed in 31.5% of participants, with the most common clinical presentation being erythematous-desquamative allergic contact dermatitis. A significantly higher likelihood of patch test positivity was observed among nurses (57.1%), particularly for nickel sensitization, compared to other occupational groups. A trend towards an association between night shift work and skin sensitization was observed, although this did not reach statistical significance. No significant associations were found for ages over 35 years, sex, or BMI. These findings highlight the elevated risk of contact sensitization among nurses, emphasizing the need for targeted interventions, including exposure reduction strategies and protective measures, to mitigate occupational skin hazards in healthcare settings. Full article