Nail disorders in children: diagnosis and management.

Nail disorders in children can be divided into seven categories. The first is physiologic alterations, which every physician should be aware of in order to reassure parents. These usually disappear with age and do not require any treatment. Among congenital and inherited conditions, the nail-patella syndrome, with its pathognomonic triangular lunula, should not be missed as recognition of the disease allows early diagnosis of associated pathologies. The most common infection is the periungual wart, whose treatment is delicate. Herpetic whitlow should be distinguished from bacterial whitlow as their therapeutic approaches differ. Dermatologic diseases encompass eczema, psoriasis, lichen planus, lichen striatus, trachyonychia, and parakeratosis pustulosa. Lichen planus, when it presents as in adults, is important to recognize because, if not treated, it may lead to permanent nail loss. Systemic or iatrogenic nail alterations may be severe but are usually not the first clue to the diagnosis. Beau lines on several fingernails are very common in children after temperature crest. Tumors are rare in children. Radiographic examination allows confirmation of the diagnosis of subungual exostosis. Other cases should undergo biopsy. Single-digit longitudinal melanonychia in children is mostly due to nevi. Its management should be tailored on a case-by-case basis. Acute trauma should never be underestimated in children and hand surgeons should be involved if necessary. Onychophagia and onychotillomania are responsible for chronic trauma.