Onycholysis refers to the detachment of the nail from the nail bed

Nail bed

Nail bed can refer to:* Bed of nails, a device sometimes used in meditation and physics demonstrations* Bed of nails tester, a device used to test printed circuit boards* Fingernail region also known as the "quick"...

, 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

Psoriasis

Psoriasis is an autoimmune disease that appears on the skin. It occurs when the immune system mistakes the skin cells as a pathogen, and sends out faulty signals that speed up the growth cycle of skin cells. Psoriasis is not contagious. However, psoriasis has been linked to an increased risk of...

. It can also occur in thyrotoxicosis and is thought to be due to sympathetic

Sympathetic nervous system

The sympathetic nervous system is one of the three parts of the autonomic nervous system, along with the enteric and parasympathetic systems. Its general action is to mobilize the body's nervous system fight-or-flight response...

 overactivity. It may also be seen in infections or trauma.

Causes

• Idiopathic
• Trauma e.g. excessive manicuring
• Infection: especially fungal
• Skin disease: psoriasis, dermatitis
• Impaired peripheral circulation e.g. Raynaud's
• Systemic disease: hyper- and hypothyroidism, reactive arthritis, porphyria cutanea tarda

Or can sometimes be because of hands in detergents