ARTICLE
Auteur(s) : Jean KANITAKIS
Dept. of Dermatology Ed. Herriot Hospital (Pav. R)
69437 Lyon cx 03, France
<jean.kanitakis@chu-lyon.fr>
Brachioradial pruritus (BRP) is an enigmatic dermatosis
characterized by persistent burning or stinging itch of the skin
over the brachioradialis muscles. It was first reported in 1968
under the term «solar pruritus». Whereas chronic sun exposure has
been considered to be the main cause of this disease [1,2], several
recent reports suggest that BRP may be a manifestation of
neuropathic pruritus, linked to spinal cord disease causing
impingement of spinal nerves [3, 4]. The treatment of BRP is not
well established. A new patient with BRP successfully treated with
gabapentin is reported herein.
A 54-year-old white man complained of severe, burning pruritus of
two years’ duration localized to the neck, shoulders and the
posterior-external aspect of both arms, spreading down to the
elbows and the upper part of the forearms. Pruritus was intractable
and worsened at night, waking the patient. Before visiting our
department, the patient had consulted a dermatologist and tried
various treatments, including oral antihistamines and creams, but
these proved ineffective. Significant sun exposure was denied;
moreover, the symptoms had no obvious relation with the summer
season. Two skin biopsies taken from the arm had shown nonspecific
findings consistent with a lesion induced by scratching. Routine
laboratory workup (including CRP, transaminases, creatinin, IgE
dosage) was within normal limits (except for slightly raised
gamma-GT values). The patient’s past medical history was
unremarkable (with the exception of surgery for biliary lithiasis).
Traumatism to the spine or neck was not recalled. Clinically, the
skin was unremarkable, save for the presence of sparse minute
papular-follicular lesions due to scratching. On the basis of these
findings, the diagnosis of BRP was made. X-ray examination showed
sagittal rectitude of the spine with protrusive codiscarthrosis at
the C5C6 and C6C7 levels.
Because of the inefficacy of previous treartments, the patient was
given, after informed consent, treatment with oral gabapentin,
starting with 300 mg/d, increased to 3 ×
400 mg/d over two months. This resulted in improvement of the
pruritus, namely over the neck. Gabapentin was further increased to
3 × 600 mg/d; after two months, no further
improvement was achieved, and the patient complained of diarrhea
and sleepiness. After an additional two-month treatment, associated
with an antipruritic cream containing 8% calamine and essential
fatty acids, the patient reported significant (90%) improvement of
pruritus; he could lead a normal life and sleep comfortably at
night. Over the next two months he voluntarily decreased the
treatment to 1200 and 600 mg/d before discontinuing it
completely; pruritus developed again on the shoulders within a few
days, although it was less severe. Gabapentin was increased to
1800 mg\d and the symptoms improved again. The patient was
lost to further follow-up.
BRP is rarely reported in the literature, but is probably
under-recognized. Its pathogenesis remains unclear. Both solar
radiation and cervical neuropathy have been incriminated. Very
recently, familial cases have been reported, inherited probably in
an X-linked, recessive pattern [5]. Treatment of BRP is difficult
and not standardized. Capsaicin cream has reportedly given good
results in some patients, but a controlled study failed to confirm
this [1]. Sun protection, amitryptiline, acupuncture, cervical
spine manipulation and application of ice packs or cold towels may
produce relief. Gabapentin (C9H17NO2) is a novel agent that has
been used successfully in the treatment of neuralgias (including
postherpetic neuralgia and allodynia), neuropathies and various
itching conditions, including uremic pruritus and BRP [6]. Its
mechanism of action is unknown, although potentiation of inhibitory
GABAergic transmission may be relevant. The effect of gabapentin on
our patient’s pruritus was obvious, since its intensity wasclearly
related to treatment. This observation further highlights BRP as an
expression of neuropathic pruritus, and upholds the usefulness of
gabapentin for its treatment. n
1. Wallengren J. Brachioradial pruritus: a recurrent
solar dermopathy. J Am Acad Dermatol 1998; 39: 803-6.
2. Wallengren J, Sundler F. Brachioradial pruritus
is associated with a reduction in cutaneous innervation that
normalizes during the symptom-free remissions. J Am Acad
Dermatol 2005; 52: 142 -5.
3. Cohen AD, Masalha R, Medvedovsky E, Vardy DA.
Brachioradial pruritus: a symptom of neuropathy. J Am Acad
Dermatol 2003; 48: 825-8.
4. Goodkin R, Wingard E, Bernhard JD. Brachioradial
pruritus: cervical spine disease and neurogenic\neuropathic
pruritus. J Am Acad Dermatol 2003; 48: 521-4.
5. Wallengren J, Dahlenbeck K. Familial
brachioradial pruritus. Br J Dermatol 2005; 153: 1016-8.
6. Winhoven S, Coulson I, Bottomley W. Brachioradial
pruritus: response to treatment with gabapentin. Br J
Dermatol 2004; 150: 786-7.
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