Contact dermatitis from topical auranofin

Peptide-Protected Gold Nanoclusters Efficiently Ameliorate Acute Contact Dermatitis and Psoriasis via Repressing the TNF-α/NF-κB/IL-17A Axis in Keratinocytes

Immune-mediated skin diseases have a high prevalence and seriously affect patients' quality of life. Gold compounds have been considered promising therapeutic agents in dermatology, but the high incidence of adverse reactions have limited their clinical application. There is a great need to develop more effective and less toxic gold-based drugs. Gold nanoclusters fabricated by using peptides (pep-AuNCs) have appeared as potential biomedical nanomaterials because of their excellent biocompatibility, ease of fabrication and unique physicochemical properties. Glutathione (GSH) is an endogenous tripeptide and has been used for lightening the skin color. Therefore, we fabricated a well-defined gold nanocluster with GSH as an example to explore the immunomodulatory effect of AuNCs on a TNF-α-treated human keratinocyte cell line (HaCaT) in vitro, the 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced irritant contact dermatitis (ICD) model and the oxazolone (OXA)-induced psoriatic model in vivo. The results indicated that topically applied AuNCs successfully attenuated the severity of ICD and psoriasis-like lesions. In vitro and in vivo, AuNCs effectively inhibited the abnormal activation of the NF-κB pathway and the consequent overexpression of proinflammatory cytokines in keratinocytes. In particular, the transactivation of IL-17A, the most important cytokine in psoriasis pathology, was effectively inhibited by AuNCs treatment. In addition, AuNCs did not show any obvious cytotoxicity in HaCaT cells at doses even up to 100 µM and did not induce any irritation in the healthy skin and major organs, which indicated their favorable biosafety. These results indicate that biocompatible pep-AuNCs might be a promising gold-based nanomedicine for the treatment of inflammatory skin diseases.

Repurposing Auranofin, an Anti-Rheumatic Gold Compound, to Treat Acne Vulgaris by Targeting the NLRP3 Inflammasome

Activation of the NLRP3 inflammasome is critical for host defense as well as the progression of inflammatory diseases through the production of the proinflammatory cytokine IL-1β, which is cleaved by active caspase-1. It has been reported that overactivation of the NLRP3 inflammasome contributes to the development and pathology of acne vulgaris. Therefore, inhibiting activation of the NLRP3 inflammasome may provide a new therapeutic strategy for acne vulgaris. In this study, we investigated whether auranofin, an anti-rheumatoid arthritis agent, inhibited NLRP3 inflammasome activation, thereby effectively treating acne vulgaris. Auranofin suppressed NLRP3 inflammasome activation induced by Propionibacterium acnes, reducing the production of IL-1β in primary mouse macrophages and human sebocytes. In a P. acnes-induced acne mouse model, injection of P. acnes into the ears of mice induced acne symptoms such as redness, swelling, and neutrophil infiltration. Topical application of auranofin (0.5 or 1%) to mouse ears significantly reduced the inflammatory symptoms of acne vulgaris induced by P. acnes injection. Topical application of auranofin led to the downregulation of the NLRP3 inflammasome activated by P. acnes in mouse ear skin. These results show that auranofin inhibits the NLRP3 inflammasome, the activation of which is associated with acne symptoms. The results further suggest that topical application of auranofin could be a new therapeutic strategy for treating acne vulgaris by targeting the NLRP3 inflammasome.

Gold--a controversial sensitizer. European Environmental and Contact Dermatitis Research Group

Until recently, gold allergy was considered to be extremely rare. Gold has been used and worshipped for thousands of years without any obvious complaints of skin problems, either in those participating in mining and other ways of prospecting, or in those wearing jewellery. When studies on contact allergy to gold sodium thiosulfate were published at the beginning of the 1990s, the allergic nature of the reported positive patch test reactions to gold was questioned. The major argument for such questioning was the lack of demonstrable clinical relevance in most positive reactors. A major reason for the questioning may have been confusion in differentiating between contact allergy and allergic contact dermatitis. To arrive at a diagnosis of allergic contact dermatitis, 3 steps have, in principle, to be fulfilled: (i) establishment of contact allergy; (ii) demonstration of present exposure; (iii) assessment of clinical relevance, i.e., causing or aggravating a contact dermatitis. In this paper, these steps are discussed with regard to gold. With our present knowledge of contact allergy-allergic contact dermatitis, we do not recommend including gold sodium thiosulfate in the standard series. It should be applied for scientific purposes and when allergic contact dermatitis from gold is suspected.

What is new in clinical research in contact dermatitis

The field of cutaneous allergy has enjoyed dynamic research advances in epidemiology and clinical contact dermatitis. Studies regarding outcomes analysis, validity, predictive value, and sensitivity have allowed clinicians to better understand the importance of patch test results. In the clinical arena, new and clinically relevant allergens are being discovered, such as corticosteroids, metals, preservatives, surfactants, and glues. Continued epidemiologic surveillance of new allergens will enable manufacturers to develop safer products for patients to use.