Notalgia Paresthetica

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.

Although the etiology of notalgia paresthetica (NP) is unclear. Multiple possible mechanisms have been proposed, including localized increased sensory innervation of the affected skin areas and neuropathy from degenerative cervicothoracic disk disease or direct nerve impingement.[8, 9, 10]  

Alai et al in 2010 demonstrated a case of notalgia paresthetica with confirmed cervicospinal disease at C4-C6.[1, 11] Savk et al in 2003 showed that more than half of their patients had significant radiographic changes in the vertebrae corresponding to the dermatome of the cutaneous lesion. Further, all study patients demonstrated normal neurological examination findings and standard electrodiagnostic results. All had skin histopathology compatible with postinflammatory hyperpigmentation. No amyloid deposits or other described pathology were noted upon pathologic examination of the skin.[12]  

Alai and Skinner in 2018 reviewed the association of BRP and notalgia paresthetica, and concurrent occurrence in the same patient, with MRI proven C5-C6 disk disease.[4]

Springall et al in 1991 concluded that the symptoms of notalgia paresthetica may, in part, be related to an increase in the sensory epidermal innervation in the affected skin areas.[9] Histological studies have shown cutaneous changes in a few cases, including lichen amyloid, which may be secondary to the localized chronic scratching and rubbing.[9, 13]

Some believe a relationship exists between notalgia paresthetica and brachioradial pruritus (BRP), because both are types of localized pruritus syndromes. The recently described association of many cases of BRP and cervical spine disease and descriptions of the disease as a possible neuropathic/neurogenic condition also support a probable neuropathic association with notalgia paresthetica.[12, 14] In contrast, notalgia paresthetica is generally unilateral, while BRP may involve the unilateral or, less commonly, bilateral upper extremities.

While the exact etiology of the cutaneous findings of notalgia paresthetica (NP) remains unknown, it is largely a dermatologic sign of an underlying systemic disease.

Notalgia paresthetica is not solely a skin disease but a cutaneous sign of an underlying musculoskeletal condition, including degenerative cervical spine disease and muscular spasm. The striking association of notalgia paresthetica with degenerative or traumatic cervicothoracic spine disease suggests that early spinal nerve impingement at the C4-C6 level may contribute to the pathogenesis of the skin symptoms of the disease in some individuals.

Additional studies are needed to further assess the relationship of notalgia paresthetica with cervical musculoskeletal disease. Whether this is a causal or coincidental finding remains to be determined in larger studies. While topical therapies may appear to help decrease the localized symptoms of notalgia paresthetica in a small percentage of patients, systemic or broader-scope cervical examination and a spinal evaluation are warranted to fully evaluate refractory cases. Cervical examination and potential spinal imaging and treatment may be appropriate as primary or first-line therapy in many cases of notalgia paresthetica.[15]

Frequency

Notalgia paresthetica (NP) is a relatively common disorder and remains largely underdiagnosed. Therefore, the true frequency may not be accurately reported. Notalgia paresthetica is described worldwide in persons of all races. National variations have not been described.

Race

Notalgia paresthetica may be seen in persons of any race, without any described racial predilection.

Sex

Notalgia paresthetica (NP) may be seen in both males and females. Sexual predilection may tend to favor females; however, large-scale studies are required to define the incidence.

Age

Notalgia paresthetica (NP) is more common in adulthood, typically in persons aged 40-80 years. The exact incidence is unknown.

Notalgia paresthetica (NP) tends to be a chronic disease with periodic remissions and exacerbations. The prognosis for control of the symptoms is good, although the condition has a natural tendency to wax and wane. Notalgia paresthetica generally is not entirely curable, although it is certainly controllable and complete remissions are possible.

While not life threatening, the cutaneous symptoms of notalgia paresthetica frequently decrease quality of life, causing much discomfort and nuisance to the affected patients. In some cases, notalgia paresthetica may become disabling and result in many secondary manifestations of cutaneous disease such as secondary skin infections, prurigo nodules, and lichen simplex.

Some increased morbidity may occur because of the possible underlying cervical and thoracic spine and disk disease. Notalgia paresthetica tends to be a chronic condition with periodic remissions and exacerbations. No increase in mortality is described for notalgia paresthetica.

Although notalgia paresthetica has not generally been described in association with other nonspine comorbidities, Alai et al have described case reports of notalgia paresthetica occurring in patients with conditions such as atopic dermatitis, elevated IgE, hepatitis C, chronic renal insufficiency, and hypereosinophilia. The exact relationship and causation remains to be elucidated.

Patient education involves discussion of possible underlying causes and associations with cervicothoracic spinal disease. Patients need to be advised of potential disease flares with exacerbations of their spinal disease.

Notalgia paresthetica (NP) patients classically present with the hallmark symptom of localized pruritus of the unilateral infrascapula. However, there are many atypical presentations of notalgia paresthetica, including localized pruritus of the upper back, neck, scalp, and shoulder.[1, 3] Frequently, patients may report a spider-bite sensation, prickly feelings, or a bra or clothing tag allergy. Often, there is an indescribable itch sensation that feels more like a dysesthesia with diffuse mild burning, some surface numbness, and almost an "under the skin" discomfort. Most of the symptoms relate to nerve sensations and may best be classified as a localized neuropathy.

The classic notalgia paresthetica (NP) patient presents with skin findings of a unilateral and ill-defined tan, pink, or hyperpigmented nonindurated patch on the infrascapular back (mid back), as shown in the image below. The affected skin area usually ranges from 3-10 cm.

Refractory notalgia mid-back in female who later developed systemic lymphoma. Courtesy of Dr. Nili Alai, The Skin Center at Laguna.

MRI of the cervical spine demonstrating disc bulges at C5-C6. Courtesy of Dr. Nili Alai, The Skin Center at Laguna.

Mildly hyperpigmented skin of right infrascapular back. Courtesy of Dr. Nili Alai, The Skin Center at Laguna.

Secondary skin changes such as lichenification, lichen amyloid, excoriations, eczema, xerosis, and secondary infection may be noted. Associated mild sensory alternations to light touch, vibration, and pin prick may be noted.

Examination of the neck may yield normal results or may reveal tenderness particularly in the C4-C7 area, minimally decreased range of motion in the neck, and possible associated cervical muscle spasm.

Possible complications of notalgia paresthetica (NP) include skin excoriations, secondary skin infection, prurigo nodules, postinflammatory hyperpigmentation, lichen amyloid, and lichen simplex chronicus.

Laboratory tests are generally not required in the evaluation of notalgia paresthetica (NP).

Although imaging tests have traditionally not been a part of the workup of notalgia paresthetica (NP), basic cervical and possibly thoracic radiographs or MRI may be warranted in the initial management of the disorder. Imaging studies may be particularly helpful in patients with contributory spine symptoms of pain, tenderness, spasm, or decreased range of motion and any history of spinal trauma or injury.[15] Note the MRI in the image below.

Cervical spine MRI demonstrating cervical disk disease and multilevel degenerative changes from C4-C5 through C7-T1. Note multiple osteophyte complexes and small disk bulges. Courtesy of Dr. Nili Alai, The Skin Center at Laguna.

Skin biopsy and tissue histology are usually not indicated for the diagnosis of notalgia paresthetica (NP). Biopsies may be performed to exclude other diagnoses and neoplasms. No criteria for tissue diagnosis of notalgia paresthetica are described, but some believe the macular amyloidosis of the mid back is part of the spectrum of notalgia paresthetica. Published studies have shown various histologic findings, including, postinflammatory hyperpigmentation and localized amyloid.[13]

Notalgia paresthetica (NP) is often refractory to standard dermatological treatments. Previously, no clearly described etiology and no uniformly effective treatment had been reported for notalgia paresthetica. Topical antipruritic compounds containing camphor and menthol traditionally have been used and have been reported as being of some benefit, albeit limited, as may topical capsaicin. Therefore, treatment of notalgia paresthetica with topical modalities, including topical steroids, generally yields partial-to-negligible responses. While topical therapies may, in some cases, seemingly help decrease the localized symptoms of notalgia paresthetica, systemic or broader-scope spinal evaluation and therapy may be warranted to fully evaluate refractory cases.

It is important to note that during the initial assessment of patients with notalgia paresthetica, a thorough history should be obtained and any findings of osteoarthritis, prior neck trauma, motor vehicle accidents, vertebral fracture, cervical neoplasm or malignancy, or cervical disk disease should be noted. Even in the absence of a positive medical history, radiography or MRI of the cervical spine may aid in early diagnosis and treatment of degenerative spine disease.

The first-line treatment for patients with notalgia paresthetica with underlying spinal disease is evaluation and conservative management of their spine and paraspinal muscles by physical therapy, massage, spinal manipulation, acupuncture, orthopedic surgery, pain management, and other musculoskeletal management. Agents such as oral gabapentin used for neuropathic pain have demonstrated some efficacy.[16]

The striking association of notalgia paresthetica with degenerative or traumatic cervicothoracic spine disease suggests that early spinal nerve impingement may contribute to the pathogenesis of the skin symptoms of the disease. While additional large scale studies are likely needed to further assess the relationship of notalgia paresthetica with cervical spine disease, the current literature supports that an association exists.

Currently, first-line therapy for notalgia paresthetica with associated cervical disease may include nondermatologic, noninvasive treatments such as spinal manipulation,[17] physical therapy, cervical soft collars, massage, cervical traction,[18] cervical muscle strengthening and increasing range of motion, transcutaneous electrical nerve stimulation (TENS),[19] cervical diskectomy with fusion, oral nonsteroidal anti-inflammatory medications (eg, ibuprofen, celecoxib, ketorolac), and oral muscle relaxants (eg, carisoprodol, cyclobenzaprine, methocarbamol, metaxalone).

Control studies on the treatment of notalgia paresthetica and related conditions are lacking.[20] A British general practitioner has reported a benefit for deep intramuscular stimulation acupuncture to the paravertebral muscles in the dermatomal segments of the body affected by pruritus in a small retrospective series with no controls.[21] Successful treatment with botulinum toxin A has also been reported.[22] Other medical and surgical measures for degenerative disk cervical disease and nerve impingement may also be considered.

For more generalized and chronic pruritus, laboratory evaluation, including complete blood cell count, chemistry panel (including renal and liver function tests), IgE level, chest radiography, thyrotropin, and in some cases serum protein electrophoresis, may be warranted to exclude underlying physiologic causes of pruritus.

Surgical therapy for notalgia paresthetica (NP) with associated cervical disease may include trigger-point injections and steroid injections, and cervical nerve and/or paravertebral blocks for severe or highly refractory cases. Other treatments include diskectomy with fusion, disk replacement surgery, minimally invasive injectable disk repair techniques, and other surgical measures for degenerative cervical disease and nerve impingement.

Proper evaluation and management of notalgia paresthetica (NP) may involve a multispecialty cooperative effort including dermatologists, radiologists, orthopedic surgeons, neurologists, pain management specialists, acupuncturists, massage therapists, and physical therapists.

Consultations with other specialists may be warranted based on radiologic findings and individual patient history and physical examination results.

No dietary treatments or associated factors are described in notalgia paresthetica (NP).

Certain physical activities may potentially worsen notalgia paresthetica (NP) via exacerbation of the underlying cervicothoracic spine disease.

In particular, physical activities that exacerbate neck spasm and activities that promote excessive forward bending of the head tend to worsen symptoms. Heavy lifting and forward movement of the arms in front of the body also tend to exacerbate symptoms in some patients. Prolonged personal computer work reportedly has caused an increase in neck posture problems and exacerbation of notalgia paresthetica in susceptible individuals.

Treatment of any underlying musculoskeletal cervical pathology may help prevent, reverse, or delay the onset of notalgia paresthetica (NP) in some patients. Proper posture and cervical health may be important in the prevention of notalgia paresthetica in susceptible individuals. Moreover, treatment of underlying conditions predisposing an individual to pruritus and laboratory evaluation of such conditions may be helpful.

Notalgia paresthetica (NP) may be most effectively treated by evaluation and therapy aimed at the cervical musculoskeletal system. Outpatient cervical spine and muscle treatment, including transcutaneous electrical nerve stimulation (TENS)/electrical muscle stimulation (EMS), acupuncture, physical therapy, and cervical traction modalities, may be considered. Physical therapy, chiropractic maneuvers, and massage treatment may all be effective interventions in addressing the underlying cervical disease.

For appropriate candidates with demonstrated cervical disease through orthopedic and/or physical therapy evaluation, home TENS/EMS units as well as cervical traction units are available, including the horizontally based Saunders traction device and many over-the-door hanging types of traction.

While no uniformly effective topical treatment has been reported for the cutaneous symptoms of notalgia paresthetica (NP), common first-line dermatologic medications have previosuly  typically included potent topical steroid creams and topical antipruritics like capsaicin. 

Prior to the new paradigm shift in treatment of the underlying spine as first-line therapy, previously accepted therapeutic options for the localized itch syndromes included capsaicin cream,[23] eutectic mixture of local anesthetic (EMLA) cream, topical steroids, pramoxine cream, topical cooling or ice pack applications, oral steroids, Tiger balm, camphor and menthol creams, flurandrenolide tape (Cordran Tape), intralesional corticosteroid injections, botulinum toxin injections,[22] oral antihistamines, hydroxyzine, doxepin, topiramate (Topamax), anticonvulsant medications, carbamazepine (Tegretol), antidepressant medications, gabapentin (Neurontin), oxcarbazepine,[24] and thalidomide.[25]

Second-line therapy for notalgia paresthetica includes medications such as oral nonsteroidal anti-inflammatory medications (eg, ibuprofen, celecoxib, ketorolac) and oral muscle relaxants (eg, carisoprodol, cyclobenzaprine, methocarbamol, metaxalone).

It is relevant to note that some of the systemic or oral therapies may exert their effect through the spinal nerves and central nervous system, thereby supporting the neuropathic etiology of notalgia paresthetica.[8, 15]

More important is that there is now a new shift in the treatment of notalgia paresthetica with therapies aimed at the spine, not the skin.[4, 5, 15, 17, 18]

Clobetasol propionate (Temovate, Clobex, Cormax)

Clobetasol propionate is a class I superpotent topical steroid; it suppresses mitosis and increases the synthesis of proteins that decrease inflammation and cause vasoconstriction. Clobetasol propionate decreases inflammation by stabilizing lysosomal membranes, inhibiting PMN and mast cell degranulation.

Fluocinonide (Lidex)

Fluocinonide is a high-potency steroid that inhibits cell proliferation. It is immunosuppressive, antiproliferative, and anti-inflammatory. Fluocinonide also has antipruritic and vasoconstrictive properties.

Triamcinolone topical (Aristacort)

Triamcinolone topical is used for inflammatory dermatosis responsive to steroids; it decreases inflammation by suppressing the migration of PMNs and reversing capillary permeability. It is available in ointment (0.1%) and cream (0.025%, 0.1%, 0.5%).

Hydroxyzine hydrochloride (Atarax, Vistaril)

Hydroxyzine hydrochloride antagonizes H1 receptors in the periphery. It may suppress histamine activity in the subcortical region of CNS.

Capsaicin topical (Capzasin-P and Zostrix)

Capsaicin is a natural chemical derived from plants of the Solanaceae family. It penetrates deep for temporary relief of minor aches and pains of muscles and joints associated inflammatory reactions. Capsaicin may render skin and joints insensitive to pain by depleting substance P in peripheral sensory neurons. It has demonstrated effectiveness in several studies of diabetic neuropathic pain and in other types of neuropathic pain.