Notalgia paresthetica (NP) is a sensory neuropathic syndrome of the mid back skin, classically described as the unilateral infrascapular area. Notalgia paresthetica is primarily a localized pruritus and dysesthesia syndrome, and it may present with episodic itching or pain on a small patch of the skin around T2-T6, usually an area of skin just past easy reach. Notalgia paresthetica is very common; however, it remains heavily underrecognized and largely underdiagnosed. [1, 2]

Atypical presentations of notalgia paresthetica have been described, including localized pruritus of the upper back, scalp, and shoulder. [1, 3] Also described are atypical presentations of an itchy back consistent with notalgia paresthetica accompanied by concurrent or serial presentation of itchy forearms, arms, and/or lower extremities, including the soles. Most recently, notalgia paresthetica has also been described in association with brachioradial pruritus (BRP) in a large number of patients. [4] Often, BRP may involve one or both forearms and may be episodic in nature, similar to notalgia paresthetica.

Accordingly, in 2020 Alai introduced a new term skin-itch-spine-syndrome (SISS), which encompasses notalgia paresthetica and its related spinal paresthesias. Spinal paresthesias, or spinal paresthetica, are neurocutaneous disorders that embody the SISS, including notalgia paresthetica, BRP, meralgia paresthetica, and burning scrotum syndrome. [5]

Additional features of notalgia paresthetica may include localized burning, pain, tenderness, hyperalgesia, or dysesthesias. [6] Notalgia paresthetica may be associated with a poorly circumscribed tan or hyperpigmented patch in the symptomatic area. Notalgia paresthetica tends to be a chronic condition with periodic remissions and exacerbations. While not life threatening and not generally associated with other comorbidities, notalgia paresthetica frequently decreases quality of life, causing much discomfort and nuisance to the affected patients.

Generally speaking, notalgia paresthetica is described in relatively high association with cervical musculoskeletal disease, particularly at the C5-C6 level. Although radiographically documented cervical spinal disease is not uncommon, it is not a requirement to make the diagnosis of notalgia paresthetica.

Even in the absence of radiographic findings, a significant number of notalgia paresthetica patients have a history of neck pain at some time in their life, painful neck muscle spasm, asymptomatic neck spasm, interscapular pain, arthritis, and neck injuries. Treatment of the underlying neck pathology through nondermatologic modalities often results in temporary improvement of the notalgia paresthetica symptoms. Therapies, including transcutaneous electrical nerve stimulation (TENS) and electrical muscle stimulation (EMS) of the neck, have proved to be some of the most effective and promising treatments for this otherwise refractory condition.

Conversely, topical treatments aimed primarily at the affected back skin are essentially unsatisfactory and ineffective. Traditionally, therapies such as capsaicin have been described as prior mainstays in treatment of notalgia paresthetica; however, therapies aimed at treating the underlying musculoskeletal pathology are likely much more effective than using topical therapies aimed at essentially masking the cutaneous symptoms. [7]

Notalgia paresthetica is not seen commonly, if at all, in the pediatric population and is most commonly seen in adults aged 40-80 years. There is a described female predominance for notalgia paresthetica.

Often, these pruritic conditions are observed in the absence of any other skin pathology and the presence of a history of cervical pain or trauma. It is therefore important to consider atypical variants of notalgia paresthetica in patients presenting with refractory, recurrent bouts of localized pruritus in essentially healthy skin and of otherwise undetermined etiology. A review of systems evaluation for relevant cervical disease and a contributory physical examination for palpable cervical muscle spasm and tenderness may be diagnostic for notalgia paresthetica.