Anatomy and physiology of the nail unit -- Abnormalities of the nail contour -- Psoriasis -- Onychomycosis --Future therapies for onychomycosis -- Lichen planus -- Pseudomonas infection -- Herpes simplex (herpetic whitlow, herpetic paronychia) -- Warts -- Acrodermatitis continua of Hallopeau -- Acute paronychia -- Chronic paronychia -- Yellow nail syndrome -- Eczema -- Nail fragility syndrome -- Onycholysis -- Onychotillomania -- Nail abnormalities in oncology practice -- Bowen's disease -- Squamous cell carcinoma -- Melanonychia -- Longitudinal erythronychia -- Exostosis -- Glomus tumor -- Myxoid pseudo cyst (mucous cyst, ganglion) -- Nail cosmetics and real nail prostheses -- Onchocosmeceuticals -- Nail surgery -- Complications in nail surgery -- Biopsy of the nail area -- Matricectomy -- Removal of the proximal nail fold: Why?