Randy Jacobs, M.D. Patient Education
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Notalgia Parasthetica
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