ABSTRACT
Painful nail is a frequent condition. The sensory nerves to the dorsum of the distal phalanges of the second, third, and fourth fingers are derived from fine oblique branches of the volar collateral nerves. Longitudinal branches of the dorsal collateral nerves supply the nails of the thumb and the fifth digit. The dorsal branches usually run to the nail fold and pass under the nail bed at the level of the lunula, although there are minor variations. The distal digit has sensory and autonomic nerves. Autonomic nerves are nonmyelinated and end in fine arborizations. Sensory nerves end in either free nerve endings or special end-organ receptors. Pain and temperature are perceived by a dermal network of unmyelinated free nerve endings. Special receptors include abundant Merkel-Ranvier endings, Meissner's corpuscles, and Vater-Pacini corpuscles. Merkel's endings are touch receptors that associate with basal cells in the deep aspect of intermediate rete ridges, and they also are generally found elsewhere in the skin.
