Phototherapy reduces the number of epidermal and CGRP-positive dermal nerve fibres

Pruritus in primary biliary cirrhosis: pathogenesis and therapy

Pruritus is a symptom experienced by patients who have primary biliary cirrhosis. It seems to result from pruritogens that (as a result of cholestasis) accumulate in plasma and other tissues, and which lead to altered neurotrasnmission. Administration of medications that change opioid neurotransmission (ie, opiate antagonists) results in relief of pruritus and its behavioral manifestation, scratching. Through unknown mechanisms, other centrally acting medications, including antidepressants, may have ameliorating effects on the pruritus of cholestasis. Stimulating endogenous detoxification pathways in the liver may also lead to the amelioration of pruritus. The removal of pruritogens through administration of nonabsorbable resins, nasobiliary drainage, biliary diversion, plasmapheresis, and various dialysis procedures is reported to decrease pruritus in liver disease, although the substances that are presumably removed are unknown.

Narrow-band ultraviolet B phototherapy in patients with recalcitrant nodular prurigo

Management of nodular prurigo has been less than satisfactory. Conventional therapies such as systemic antihistamines and topical steroids have not been particularly successful. The effects of narrow-band ultraviolet B (NB-UVB) phototherapy in the treatment of various inflammatory dermatoses have been proven, however, no data exist on the efficacy and the duration of remission in NB-UVB monotherapy for nodular prurigo. The aim of this study was to evaluate the effect of NB-UVB phototherapy on recalcitrant nodular prurigo. NB-UVB phototherapy was performed once a week on 10 patients with recalcitrant nodular prurigo. The initial dose was 0.4 J/cm(2), and the dose was increased by 0.1 J/cm(2) for each treatment. The treatment was performed until the eruption was almost clear. In each patient, a mean cumulative dose of 23.88 J/cm(2) was applied over a mean of 24.3 irradiations. The mean maximum daily dose of ultraviolet B was 1.2 +/- 0.4 J/cm(2). NB-UVB phototherapy notably improved the eruption of nodular prurigo in all patients. Follow up at 1 year revealed that only one patient had relapsed. The remaining nine patients continued to derive long-term benefits. NB-UVB phototherapy appears to be an effective treatment for recalcitrant nodular prurigo, offering long-term benefits in the majority of those treated.

Generalized pruritus treated with narrowband UVB

BACKGROUND

Narrowband UVB phototherapy has been increasingly used in a variety of dermatological diseases. We planned to evaluate its efficacy in generalized pruritus in this prospective study.

METHODS

Forty-six patients were included and then divided into two groups: group 1 and group 2 consisted of patients with uremic pruritus and "idiopathic pruritus", respectively. Phototherapy was given three times a week. Efficacy assessments were made by means of visual analog scale (VAS) and pruritus grading score.

RESULTS

Thirty-five patients completed the treatment. Mean VAS decreased from 8.2 +/- 1.5 to 3.6 +/- 3 in group 1 and from 7.1 +/- 2.3 to 2.3 +/- 2.8 in group 2 (P < 0.0001). Mean percentage of change in VAS was 54.2% (95% CI 32.6-75.9) and 67.9% (95% CI 53.8-81.9) in group 1 and group 2, respectively. Mean number of treatments was 22 in both groups. Mean cumulative UVB dose was 24,540 mJ/cm(2) and 20,801 mJ/cm(2) in group 1 and group 2, respectively.

CONCLUSION

Narrowband UVB is an effective and well-tolerated treatment option for patients with generalized pruritus.

Cutaneous innervation before and after one treatment period of acupuncture

BACKGROUND

The effect of acupuncture on nociceptive pain is well documented, but effects on nociceptive itch have been contradictory.

OBJECTIVES

To evaluate possible effects of acupuncture on the occurrence, distribution and function of sensory nerve fibres in human skin.

METHODS

Ten subjects were treated by inserting 10 acupuncture needles subcutaneously at the upper lateral aspect of one buttock. The subjects were recruited from an acupuncture clinic and were undergoing specific acupuncture treatment for their disorders. The needles were stimulated (rotated to and fro) twice during the twice-weekly 25-min sessions over 5 weeks. Skin biopsies, diameter 3 mm, were taken before and 3-6 days after local acupuncture. Antibodies to the pan-neuronal marker protein gene product 9.5 (PGP 9.5), calcitonin gene-related peptide (CGRP), vanilloid receptor 1 (VR1) and mu- and delta-opioid receptors were employed to study sensory unmyelinated nerve fibres that transmit nociceptive pain and itch. A histamine prick test using planimetry was used to record experimental itch after acupuncture on the treated area and on the corresponding control skin, and a visual analogue scale was used to evaluate itch.

RESULTS

The mean +/- SEM number of CGRP-immunoreactive nerve fibres per biopsy section was reduced from 36.0 +/- 3.3 to 21.3 +/- 4.0 (P = 0.05) after the treatment. PGP 9.5-immunoreactive nerve fibres were found both in the epidermis and in the subpapillary dermis. The mean +/- SEM total number of PGP 9.5-immunoreactive nerve fibres decreased from 249.8 +/- 16.7 to 211.8 +/- 12.0 (P = 0.03). The PGP 9.5-immunoreactive nerve fibres occurring in the dermis appeared more fragmented after the acupuncture compared with pretreatment. VR1 immunoreactivity was found both in the free nerve fibres and in kite-like formations, possibly mast cells, throughout the dermis, sometimes occurring around hair follicles. The mean +/- SEM number of VR1-immunoreactive elements was not significantly influenced by acupuncture, at 33.5 +/- 4.6 vs. 43.0 +/- 4.4 (P = 0.09). No immunoreactivity was found in the skin against mu- and delta-opioid receptors with the antibodies used in this study. Neither histamine-induced itch nor cutaneous responses were influenced by acupuncture.

CONCLUSIONS

The present data indicate an effect of acupuncture on neuropathic itch but not histamine-mediated itch. Our findings support the opinion that the pain-relieving effects of acupuncture partly depend on its effect on the peripheral innervation.

Broad-band ultraviolet B phototherapy in zoster patients may reduce the incidence and severity of postherpetic neuralgia

BACKGROUND

Postherpetic neuralgia (PHN) is one of the common complications of herpes zoster infection, particularly in the elderly. Current therapeutic measures are only partially effective in the affected patients. As inflammatory mediators released by different cells play an important role in the pathogenesis of this neuropathic pain and with regard to the immunomodulatory effects of ultraviolet B (UVB) spectrum, we presumed that UVB phototherapy might be effective in the prevention of PHN.

METHOD

This study was performed in two phases. Phase I was a prospective open controlled trial. Twenty-five patients with severe pain in the first 7 days of zoster rash were divided into two groups: the prevention group (n=12) received oral acyclovir (800 mg five times a day for 10 days) plus broad-band UVB to the affected dermatomes, starting with 20 mJ/cm(2) and gradually increasing the dose by 10 mJ/cm(2) each session to a maximum dose of 100 mJ/cm(2). Treatment sessions were repeated three times a week until pain relief or to a maximum of 15 sessions. The control group (n=13), who had disease characteristics similar to the prevention group, received only oral acyclovir with the same dose. All patients reported their severity of pain on a verbal rating scale (VRS, score 0-4) before treatment and at 1 and 3 months' follow-up. In phase II of the study, five patients with established PHN (more than 3 months after rash onset) received UVB with the above-mentioned protocol.

RESULTS

A total of 17 patients older than 40 (10 females, seven males; mean age, 65.5 years; range: 47-82 years) who had intractable pain due to zoster infection received UVB in two phases of the study. In patients who received phototherapy in the first 7 days of rash, 58.33% and 83.33% were completely pain free at 1-and 3-month follow-up, respectively. The corresponding figure in the control group was significantly lower (38.46% at 1 month and 53.85% at 3 months). The severity of pain was also lower in the phototherapy group than the control group (mean VRS 2.50 vs. 3.28 at 3 months). None of the patients who were treated more than 3 months after rash onset (established PHN) experienced significant (more than 50%) pain relief.

CONCLUSION

UVB phototherapy in the acute stage of zoster rash might reduce the incidence and severity of PHN. Treatment after 3 months does not seem to have a significant beneficial effect.

Treatment of uremic pruritus with narrowband ultraviolet B phototherapy: an open pilot study

We report the results of a pilot study of narrowband ultraviolet B phototherapy for the treatment of 20 patients with uremic pruritus. Ten patients completed the 6-week study period. A total of 8 patients were found to be responders. Of the remaining 10 patients who left the study before 6 weeks, 6 were satisfied with the response. In the follow-up period, 7 responders could be examined, and 3 were in remission 6 months after completing treatment. However, pruritus recurred in the remaining 4 responders. Narrowband ultraviolet B phototherapy may be an effective treatment for patients with uremic pruritus. Recurrence of pruritus, however, is a frequent problem.

A randomised controlled trial on photo(chemo)therapy of subacute purigo

BACKGROUND

Psoralen ultraviolet A (PUVA) is the standard photo(chemo)therapeutic regimen for patients suffering from subacute prurigo (SP).

HYPOTHESIS

Regarding efficacy, bath PUVA is not superior to medium-dose ultraviolet-A1 (MD-UVA1) and narrowband ultraviolet-B (NB-UVB), which may be considered the new photo(chemo)therapeutic options for SP.

METHODS

We performed a prospective randomised, controlled, three-arm photo(chemo)therapeutic study. Patients suffering from histopathologically proven SP with a clinical score (PIP score; papules, infiltration and pruritus) of at least 5 points were enrolled into the study. Treatment with bath PUVA was performed 4 times weekly and MD-UVA1 and NB-UVB 5 times weekly. Photo(chemo)therapy was administered over a 4-week period. Outcome measure was the severity of SP investigated by means of the PIP score after 4 weeks of therapy.

RESULTS

In total, 33 patients with SP were randomly allocated to photo(chemo)therapy. Bath PUVA (n = 9), MD-UVA1 (n = 11) and NB-UVB (n = 13) resulted in a significant reduction of the baseline PIP score as assessed on the basis of intention-to-treat (ITT) analysis (P = 0.003). However, ITT analysis revealed significantly higher PIP score reduction in patients who were treated with bath PUVA and MD-UVA1 compared with NB-UVB (P < 0.01, 95% CI 1.1-3.63 and P < 0.05, 95% CI 0.42-2.70, respectively).

CONCLUSIONS

Photo(chemo)therapy, including bath PUVA, MD-UVA1 and NB-UVB, appears to be an effective and safe treatment option for patients suffering from SP. UVA1 and particularly PUVA seem superior to NB-UVB in the management of SP.

Neuroimmunological findings in allergic skin diseases

PURPOSE OF REVIEW

Recent studies have gained widespread information about the complex regulation of genetic, environmental, immunologic, and pharmacologic factors that contribute to the development of allergic inflammatory skin diseases such as atopic dermatitis. Neuroimmune mechanisms, however, still remain to be elucidated. This review will focus on the interaction between the cutaneous immune and peripheral nervous system in allergic inflammatory skin such as atopic dermatitis.

RECENT FINDINGS

Neuropeptides and neuropeptide-positive nerve fibres are prominently increased in lesions of atopic dermatitis. The density of nerve fibres is increased while peripheral nerve endings are in an active state of excitation. In this regard, neurotrophins particularly described for their functional role on nerve cells are also expressed in atopic dermatitis skin. In addition, neurotrophins modulate the functional role of eosinophils as main target effector cells in atopic dermatitis, as described recently. Interestingly, eosinophils are capable of neurotrophin as well as neuropeptide production itself, pointing to a bidirectional communication between neuronal cell populations and main target effector cells.

SUMMARY

Neurotrophins and neuropeptides modulate both the functional activity of sensory neurons and immune cells. We have therefore developed the concept of a neuroimmune network between target effector cells and sensory nerves that links pathogenic events to dysfunctions of the cutaneous immune and peripheral nervous system in allergic inflammatory skin diseases.

Ultraviolet phototherapy for pruritus

Ultraviolet-based therapy has been used to treat various pruritic conditions including pruritus in chronic renal failure, atopic dermatitis, HIV, aquagenic pruritus and urticaria, solar, chronic, and idiopathic urticaria, urticaria pigmentosa, polycythemia vera, pruritic folliculitis of pregnancy, breast carcinoma skin infiltration, Hodgkin's lymphoma, chronic liver disease, and acquired perforating dermatosis, among others. Various mechanisms of action for phototherapy have been posited. Treatment limitations, side effects, and common dosing protocols are reviewed.

Neuroanatomy and neurophysiology of itch

The specific pathway of "pure," histaminergic itch is traced from the mechano-insensitive nerve fibers in the skin to their central cortical projections. Neuropathic itch created at different levels of this anatomical pathway is reviewed. In this review the present author discusses damage to pruritoceptors in the skin, entrapment syndromes, damage to spinal ganglia, nerve root impingement, injury of the spinal cord, and cerebral damage in the distribution of the middle cerebral artery, capsula interna, or thalamus. Itch in inflamed skin resulting from interactions between nerve transmitters and other mediators of inflammation is described.

Photodamage to the cutaneous sensory nerves: role in photoaging and carcinogenesis of the skin?

Chronic exposure to ultraviolet radiation (UVR) plays a significant role in aging and carcinogenesis of the skin. Sensory nerve fibers densely innervate all layers of the skin and get in close anatomical as well as functional contact with cellular components of the epidermis and dermis. In this review, we address the impact of acute and chronic UVR exposure on the cutaneous sensory nervous system and its mediators. We suggest that skin cell-derived nerve growth factor (NGF) and skin nerve-derived neuropeptides such as substance P (SP) and calcitonin gene-related peptide (CGRP) may play a central role in intrinsic aging as well as extrinsic (photo-) aging of the skin. In addition, we discuss the possible role of these mediators in photocarcinogenesis.

Brachioradial pruritus is associated with a reduction in cutaneous innervation that normalizes during the symptom-free remissions

BACKGROUND

There has been a controversy regarding the cause of brachioradial pruritus: is it caused by a nerve compression in the cervical spine or is it caused by a prolonged exposure to sunlight?

OBJECTIVE

The purpose was to study clinical features of patients with brachioradial pruritus and to compare the cutaneous innervation in punch biopsies from the itchy skin of patients with the age-matched controls.

METHODS

Skin biopsy specimens from itchy skin of 16 patients with brachioradial pruritus were collected during the early autumn and were compared with corresponding skin specimens from 11 age-matched controls in the early spring, four of the patients being their own controls. The cutaneous innervation was visualized by antibodies against protein gene product 9.5 (general neuronal marker), by antibodies against calcitonin gene-related peptide (marker for thin sensory nerve fibers), and by antibodies against VR1-receptor (marker for capsaicin-sensitive nerve fibers).

RESULTS

In all but two of the patients, itching of the arms or shoulders was seasonal. Some patients reported neck pain. In the skin of the lower arm, the number of protein gene product 9.5 immunoreactive nerve fibers was reduced 23% as compared with controls ( P = .03), the number of intraepithelial nerve fibers being reduced by 27% ( P = .03). The number of calcitonin gene-related peptide immunoreactive nerve fibers in the dermis was reduced by 34% ( P = .02) and the number of capsaicin-sensitive nerve fibers by 43% ( P = .008). The innervation of the four patients who were their own controls became normalized during the symptom-free period.

CONCLUSIONS

The temporal course of the brachioradial pruritus and the histological changes in the skin similar to those caused by ultraviolet light, indicate that sunlight is an eliciting factor and that cervical spine disease can be a predisposing factor.