Localized pruritus-notalgia paresthetica

Abstract

Notalgia paresthetica, possibly an isolated sensory neuropathy involving the posterior primary rami of thoracic nerves T2 through T6, and appearing as pruritus of the back, is apt to be encountered by both dermatologists and neurologists. Two cases illustrate this disorder.

Localized hyperpigmentation and pruritus on the upper back

“…Although the etiology of the condition is unknown, some authors con- sider it a toxic neuropathy following the report of a case in which the symptoms were associated with the ingestion of saccharine [4]. Others are of the opinion that genetic factors would be involved [5], with the suggestion of an X-linked dominant pattern.…”

“…However, it appears that the most aecepted pathogenetic theory [3,[5][6][7][8] is that it is a neuropathy due to trapping, since the posterior branches of the T2 to T6 spinal nerves cross the multifid musele (transverse spinal), following a right-angled trajectory, an anatomical disposition that renders them more accessible to small traumatisms. Clinically, NP is reflected in dysesthesias in the upper part of the back, above all in the form of pruritus, although it may also beeome manifest in the form of a burning sensation, a tingling feeling, pain, [1,9] etc.…”

“…The condition may be accompanied by local hyperpigmentation in the form of a plaque (sometimes several [8]) with ill-defined borders and a reticulated aspect. Neurological exploration of the area may reveal alterations in tactile, vibratory and thermal sensitivity and in nociception [1,7] together with anomalous responses in sweat tests [1]. Associated neuropathies are also seen [3].…”

Dermatomal Pruritus of the Upper Limb: A Manifestation of Nerve Root Compression due to Degenerative Spine Disease?

“…Pruritus is rarely observed in association with lesions of the peripheral nervous system. Notalgia-paresthetica, a form of pruritus involving the parascapular region and considered to be sporadic by Massey (5) and hereditary by Comings et al (6), is attributed to a peripheral neuropathy affecting the posterior branch of the dorsal nerve roots. Post-herpetic pruritus is also due to peripheral nerve lesions (7).…”

Notalgia Paresthetica: A Novel Approach to Treatment with Cryolipolysis

“…Usually, the condition is unilateral; rarely it is bilateral. A hyperpigmented patch, with or without accompanying hyperkeratosis or lichenification, may be present at the site of the symptoms [ 1 - 4 , 9 , 10 , 12 - 14 ].…”