ABSTRACT

There are a vast number of systemic disorders potentially causing or being associated with nail changes. They are cardiovascular disorders, respiratory diseases, gastrointestinal diseases, hepatic diseases, renal and genitourinary diseases, reproductive system diseases, endocrine diseases, musculoskeletal diseases, connective tissue diseases and immunological diseases. Drug-induced nail alterations are very varied and may be classified according to the drug classes, their indications, or the particular nail lesions they cause. Clubbing usually occurs in stages, beginning with a periungual erythema and a softening of the nail bed. Osler's nodes are small tender red nodules around the nail developing within hours or days. In the early phase of obstructive arterial disease, the nail becomes dystrophic, thin, brittle, and fragile. Nail dystrophy occurs in several deficiency states. Nail clippings from the distal part reveal irregular nail substance without any diagnostic features. Intestinal polyps and pigmented macules of the lips, periorificially, on fingers, toes, and nails are the diagnostic criteria for Peutz–Jeghers syndrome.