Exposome Impact on Nail Health

Abstract

Background: The nail unit is a complex system with various components, each serving distinct functions. The exposome, encompassing external and internal factors such as UV radiation, air pollution, dietary habits, and cosmetic product usage, substantially influences nail health and can lead to premature nail aging.

Summary: Internal and external exposomal factors can impact differently on nail health, inducing a variety of different clinical conditions. Effective therapeutic strategies exist, but a comprehensive understanding of how the exposome affects nails is lacking. This article aims to bridge this knowledge gap by exploring the relationship between the exposome and nail health, emphasizing it as a central focus of our analysis.

Key messages: (1) The exposome, comprising various external and internal factors, may significantly influence nail health negatively, leading to premature nail aging. (2) Different nail conditions may arise due to the exposomal influence on nails. (3) Understanding the exposome's impact on nail health is crucial for developing solutions to mitigate negative effects and improve overall nail well-being.

Keywords: Brittle nails; Drug-induced nail disorders; Exposome; Manicure; Nail aging; Nail disorders; Nail straightening solution.

Fig. 1.

Global photography of nail condition due to aging. Koilonychia (a), a condition causing nails to become abnormally thin and concave, often associated with iron deficiency; pincer nails (b), where the edges of the nails curve inward, causing discomfort and potential nail damage; onychogryphosis (c), a condition involving nail overgrowth, often leading to thick, curved, and misshapen nails; and an ingrown nail (d), classically associated with erythema, swelling, and a pyogenic granuloma in the affected area.

Fig. 2.

Global photography of nail affections due to internal exposomal factors. Splinter hemorrhage in nails (a), with dermoscopic close-up look (b), characterized by small red or brown streaks under the nails, often associated with trauma. c Muehrcke’s lines, transient horizontal white bands that appear in the nail bed and are often associated with various health conditions. d Nail clubbing, a condition where the nails thicken and curve around the fingertips, is often indicative of underlying lung issues or malnutrition. e Beau’s lines, which are transverse depressions in the nail plate, are often caused by severe illness or trauma that disrupts nail growth. f Onychomadesis, a condition where the nails detach from the nail bed and shed, is usually caused due to a temporary interruption in nail growth. g Paronychia, an inflammation around the nail fold, can be acute or chronic and may lead to pain and swelling. h Nail pyogenic granuloma, a benign vascular tumor occurring near the nail bed.

Fig. 3.

Global photography of nails abnormalities due to external exposomal factors. a Trachyonychia, a condition characterized by roughening and surface abnormalities of the nail plate. b True leukonychia, a condition characterized by white discoloration or spots on the nail plate, often due to nail matrix or nail plate damage. c Pseudoleukonychia, associated with whiteness of the nail plate, typically due to exogenous compounds, trauma, or skin diseases. dPseudomonas infection, a bacterial nail issue often characterized by green and black coloration of the nail plate.