Anonychia

Anonychia is the complete absence of one or more nails, typically referring to the absence of the nail plate on the fingers or toes. It can be present at birth (congenital anonychia) or develop later in life (acquired anonychia) when the nail matrix is damaged or fails to function. The term is most often used to describe a total lack of nails rather than partial nail absence.

Congenital anonychia can occur as an isolated finding or as part of a broader ectodermal dysplasia syndrome, in which other ectodermal structures such as hair, teeth, or sweat glands may be affected. Acquired anonychia results from destruction or irreversible impairment of the nail matrix, and possible causes include severe trauma, chemical or thermal injury, chronic inflammatory or infectious conditions affecting the nail apparatus, and certain medications or systemic diseases.

Clinically, the main feature is the absence of nail plates over affected digits. The nail bed skin may appear normal or there may be underlying structural abnormalities. In congenital cases, other ectodermal features may be present; radiographs can help exclude associated skeletal anomalies. Diagnosis is primarily clinical, supported by history and examination; genetic testing may be offered if a hereditary syndrome is suspected.

Management focuses on function and cosmetics, as there is no established cure for congenital anonychia. Protective nail bed care is advised, and patients may use nail prostheses or artificial nails for appearance and protection. In acquired cases, treatment targets the underlying cause and may include wound care, medical therapy for inflammatory or infectious diseases, or surgical options if appropriate. Prognosis depends on extent and underlying etiology, with emphasis on preventing injury and optimizing hand function.