Onycholysis refers to the detachment of the nail from the nail bed, starting at its distal and/or lateral attachment. It is said to occur particularly on the ring finger but can occur on any of the fingernails. The most common cause of onycholysis is psoriasis. It can also occur in thyrotoxicosis and is thought to be due to sympathetic overactivity. It may also be seen in infections or trauma.
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