Notalgia Paresthetica

 

What Is It?

Simply, patients with nostalgia paresthetica experience a frustratingly resistant itch on their back. The dermatologist may not find anything unusual on the surface of the skin, except for a slight increase in pigmentation, but the patient is bothered by continuous itch. Nostalgia paresthetica is not really caused by a skin condition, it is most likely caused by a condition of the nerves supplying the skin in which the nerves are squeezed by tense muscles. Nostalgia paresthetica is probably an isolated sensory neuropathy (a sensory nerve condition) in which itching, burning, pain, tenderness, or hypersensation occurs in one or the other infrascapular areas of the back (below the scapula). Itching is the most common symptom, and is usually the most prominent or only symptom. Decreased touch or temperature sensation in the affected area has also been reported in nostalgia paresthetica. Nostalgia paresthetica is probably far more common than you realize, especially when one understands that nostalgia paresthetica has been described under a variety of names over several decades.

 

What Does It Look Like?

 

In nostalgia paresthetica, the skin appears normal or may show secondary skin changes such as increased pigmentation and lichenification (skin thickening) caused by continuous rubbing and scratching. The scratching may also cause bleeding, but other than this, nostalgia paresthetica will show no abnormalities.

 

 

What Causes It?

 

Interestingly, most patients with nostalgia paresthetica have a stiff upper back and may be under stress. The hypothesis is that the upper back muscles remain tense and tend to squeeze the local peripheral nerves. The nerves respond by causing the itchy sensation. Nostalgia paresthetica may be the result of muscle tension, pressure, or other processes that affect certain nerves of the back (medically, the posterior rami of the second through the sixth dorsal nerves). Many patients have asked Dr. Jacobs to explain the cause of nostalgia paresthetica. It is difficult to understand the cause unless one has studied medical neurophysiology. Dermatologic studies have been done, comparing histochemically processed skin biopsy specimens from patients with nostalgia paresthetica. In one study, nostalgia paresthetica affected skin was compared with contralateral unaffected skin in five patients. Site-matched biopsies were also taken from five control subjects. The researchers detected no differences in distribution of neuropeptide-immunoreactive nerve axons after staining for the following neuro-chemicals: substance P, calcitonin gene-related peptide, vasoactive intestinal peptide, and neuropeptide with tyrosine. Interestingly, the number of immunoreactive nerve fibers reactive for protein gene product 9.5. (PGP 9.5), a general neural marker, was significantly increased in nostalgia paresthetica affected skin compared with control subjects, and with unaffected contralateral skin from the same patient. The researchers concluded that cutaneous nerves are increased in nostalgia paresthetica, as evidenced by an increased number of PGP 9.5 stained fibers.

How Is It Treated?

 

Because nostalgia paresthetica may be the result of muscle tension, pressure, or other processes that affect certain nerves of the back, it is reasonable to seek to relieve this tension. Perhaps a daily deep massage will help. Perhaps relaxation exercises can help. Chiropractors and physical therapists have helped. Osteopaths have also helped. The idea is to relieve muscle tension of the upper back. Nostalgia paresthetica may be a little itch, but it captures our attention with its unique features and lack of physical changes in the skin. Now that we know that the affected skin in nostalgia paresthetica has more than its fair share of nerve fibers, we have only to consider why. Perhaps injury to posterior rami of dorsal nerves leads to distal neural proliferation. This hypothesis is consistent with the neural proliferation seen in other dermatologic conditions such as lichen simplex chronicus and prurigo nodularis. It is evident that cutaneous neural proliferation is the primary event in many of these disorders.

 

How does treatment work? In order to treat nostalgia paresthetica, one must control the process of neural proliferation. There is little doubt that neural proliferation can be a major trigger in the self-perpetuation of the itch-scratch cycle. Whether or not increased nerve endings are the cause, it is obvious that any remedy for nostalgia paresthetica must address their presence. As might be predicted, topical capsaicin, which damages and depletes substance P from cutaneous sensory nerves, is effective in treating nostalgia paresthetica. More recently, a cream containing two local anesthetics, lidocaine and prilocaine, has also been used to treat nostalgia paresthetica successfully in three patients. This cream is now available in the United States under the name of EMLA. Dr. Jacobs usually begins treatment with a topical steroid cream to control the symptoms in nostalgia paresthetica. Certain patients have found relief by using topical capsaicin (Zostrix), an ingredient derived from hot chili peppers.

 

Should patients who present with classic nostalgia paresthetica undergo extensive diagnostic testing for neuropathies or neurologic abnormalities? If the patient does not improve, Dr. Jacobs may refer the patient to orthopedics to evaluate the integrity of the spine. Although localized changes in sensation may be detected in patients with nostalgia paresthetica, there is as yet no indication that any serious underlying disorder is at play. An important reason for diagnosis nostalgia paresthetica in such patients is the availability of relatively effective treatment. Nostalgia paresthetica patients often fail to respond to topical corticosteroids, but many do respond to topical capsaicin cream. Another therapeutic option, is lidocaine-prilocaine cream. A third reason for an accurate diagnosis of nostalgia paresthetica is that patients can be reassured that the problem is probably not serious.

 

Synonyms of Nostalgia Paresthetica

 

- Peculiar persistent pruritus

 

- Peculiar spotty pigmentation

 

- Puzzling posterior pigmented pruritic patch

 

- Hereditary localized pruritus

 

- Recurrent lichen simplex chronicus of the scapular region

 

- Macular amyloidosis of the infrascapular region

 

- Unscratchable itch                                 

 

- Muscular tension of the back