Nail dystrophy mimicking psoriatic disease caused by contact allergy to nail varnish allergens including copolymers

The Chemistry of Behind the UV-Curable Nail Polishes

As far as history tells, people have set efforts both to improve the conditions and to change the visual outfit of the skin, nails, and hair. The first information on nail cosmetics is found in ancient China and Egypt, where various nature-derived compositions were used for changing the colour of the nails. Nowadays more mechanically and chemically durable systems for nail polishes are elaborated. This review focuses on the latest achievements in the field of UV-curable nail polishes. Herein, the polymerization mechanisms of various systems (acrylates, as well as epoxides and thiols) occurring in nail polishes are described. Besides plausible side reactions of the polymerization process are characterized. Thus, the main drawbacks for forming a uniform, perfect layer are illuminated. For effective curing, the choice of photoinitiators may be crucial; thus, various types of photoinitiators as well as their main advantages and disadvantages are characterized. Ensuring effective adhesion between the substrate (human nail) and the polymer film is one of the challenges for the nail polish industry-thus the plausible interactions between the adhesion promoters and the keratin are described. Regarding the film-forming agents, a comprehensive overview of the composition of the traditional UV-curing nail polishes is provided, but the main emphasis is devoted to alternative, nature-derived film-forming agents that could introduce renewable resources into nail cosmetics. Additionally, this review gives short insight into the latest innovations in UV-curing nail cosmetics, like (1) nail polishes with improved pealability, (2) covalently polymer-bonded dyes and photoinitiators, thus reducing the release of the low-molecular compounds or their degradation products, and (3) UV-curing nail polishes as delivery systems for nail treatment medicine.

Nail Polishes: A Review on Composition, Presence of Toxic Components, and Inadequate Labeling

Nail polishes were developed in 1920, and since 1940, it has been known that these cosmetics contain toxic and sensitizing components. Over the years, nail polishes have undergone several changes in their formulation to avoid this problem, but new components have also been considered toxic and allergenic. The growing demand for gel nails has also been highlighted in cases of allergy to (meth)acrylates, and the biggest concern that was previously related to the presence of toluene sulfonamide-formaldehyde resin (TSFR) in traditional nail polish formulations is now also part of (meth)acrylate-based cosmetics. The beautification caused by nail polish is the main factor behind its constant use throughout the world, but studies have demonstrated its use for other purposes, such as treating fungal diseases, sun protection factor in cancer patients, and as a possible ally in forensic area. This review brings the beginning of the discovery of nail polish and its trajectory to the present day, including its effects on health and its inadequate labeling. Therefore, it is extremely important that legislation monitors the composition of nail cosmetics and that new formulations are studied to make them safe for health and the environment.

Differential diagnosis of contact dermatitis: A practical-approach review by the EADV Task Force on contact dermatitis

The diagnosis of eczema ('dermatitis') is mostly clinical and depends on the clinical history and exploratory objective findings (primary lesions, patterns). Contact dermatitis remains as an important condition in the group of eczematous disorders, with important socioeconomic and occupational relevance. Although irritant and allergic contact dermatitis have a different pathogenesis, both are characterized by a rather typical morphology, are triggered by external factors and tend to occur primarily in the area of contact with the exogenous agent. In addition, allergic and irritant dermatitis may also co-exist. The importance of diagnosing contact dermatitis, especially when allergic in nature, is both due to the possibility of avoiding the trigger, and due to its role in aggravating other skin conditions. Nevertheless, the heterogeneity of clinical presentations in daily practice may pose an important challenge for the suspicion and correct diagnosis of contact dermatitis. Furthermore, other conditions, with different pathogenesis and treatment, may clinically simulate contact dermatitis. The Task Force aims to conduct a review of the unifying clinical features of contact dermatitis and characterize its main clinical phenotypes, and its simulators, in order to contribute to an early suspicion or recognition of contact dermatitis and enable a correct differential diagnosis.

Allergic Contact Cell-Mediated Hypersensitivity in Psoriasis: A Narrative Minireview

The dysfunctionality of the protective skin barrier in psoriasis allows easier cutaneous penetration of various contact haptens; thus, such patients can develop allergic contact hypersensitivity as a comorbidity. Both skin conditions involve T-cell-mediated mechanisms. Dermatologists and allergists should consider assessing allergic contact cell-mediated hypersensitivity in selected psoriasis patients, especially those with palmoplantar psoriasis and who are refractory to topical treatments, and in patients with psoriasis, with or without arthritis, treated with biologics that present skin lesions clinically suggestive of contact dermatitis.