Notalgia paresthetica is a condition of the skin of the upper back that manifests as extreme pruritus in a localized area just below or medial to the scapula. Notalgia paresthetica is felt to be secondary to spinal nerve impingement, causing a sensory neuropathy and persistent itch. Pain, paresthesias, and hyperesthesias may coincide with the itch. Hyperpigmented or lichenified skin changes, if present, are due to chronic rubbing and scratching of the affected area.

Notalgia paresthetica is relatively common but perhaps underdiagnosed. It can affect people of any age, any race, and either sex. However, it is thought to be most common in middle-aged to older adults. Women seem to develop notalgia paresthetica more frequently than men. A higher body mass index has been associated with longer disease duration.

A related entity is macular amyloidosis, which can also be caused by chronic rubbing. Both notalgia paresthetica and macular amyloidosis can be cutaneous markers of multiple endocrine neoplasia (MEN) type 2, or Sipple syndrome (MEN2A), especially if onset is during childhood or adolescence. Fibromyalgia with generalized or regional pain may be a concomitant condition.

Although the etiology of notalgia paresthetica is not entirely certain, some studies have demonstrated, radiographically, degenerative changes of the spine corresponding to the level of the nerve root affecting the pruritic skin, typically T2-T6. The posterior rami of T2-T6 have a perpendicular anatomical course through the multifidus spinae muscle, which may predispose them to entrapment and injury.