Pathogenesis and treatment strategies for chronic paronychia and ingrown nails: a narrative review

Purpose: Chronic paronychia and ingrown nails (onychocryptosis) are common nail disorders that cause pain, functional impairment, and reduced quality of life. They occur frequently in both dermatology and primary care settings. Effective management requires an understanding of the underlying mechanisms and available treatment approaches. This review summarizes the etiopathogenesis, clinical features, and evidence-based management of chronic paronychia and ingrown nails, providing practical guidance for physicians. Current Concepts: Chronic paronychia is a multifactorial inflammation of the nail folds persisting for more than 6 weeks, typically initiated by disruption of the cuticle barrier. This disruption allows moisture, irritants, and microbes to penetrate the periungual area, resulting in chronic inflammation, fibrosis, and retraction. Candida species are often isolated but function predominantly as secondary colonizers. Environmental triggers such as frequent wet work, artificial nails, and anticancer therapies (including epidermal growth factor inhibitors and taxanes) can further compromise the periungual barrier. Ingrown nails arise from penetration of the nail plate into, or overgrowth of, hypertrophic folds. These changes are promoted by improper trimming, tight footwear, anatomical predisposition, systemic disease, or trauma. Discussion and Conclusion: Management primarily aims to remove triggers, control inflammation, and restore the periungual barrier. Early stages usually respond to conservative measures, including topical corticosteroids, calcineurin inhibitors, antifungal agents, footwear modification, nail splinting, and patient education. Severe or refractory cases may require surgical intervention, such as square flap excision for chronic paronychia or partial nail avulsion with phenol matricectomy and soft tissue resection for ingrown nails. Individualized therapy can improve outcomes, minimize recurrence, and enhance quality of life.