Itching

Handb Exp Pharmacol. 2015;226:337-356.

Current Topical and Systemic Therapies for Itch.

Leslie TA1, Greaves MW, Yosipovitch G.

Author information

  • 1Royal Free Hospital, London, UK, Tabi.Leslie@gstt.nhs.uk.

Abstract

Itch is a common distressing symptom which may be caused by multifactorial aetiologies including inflammatory skin diseases, systemic diseases, neuropathic conditions and psychogenic disorders. Itch is a term used synonymously with pruritus and is defined as acute if it lasts less than 6 weeks or chronic if it persists for more than 6 weeks. It can have the same impact on the quality of life as chronic pain and shares many of the same pathophysiological pathways. Depending on the aetiology of the itch, different pathogenic mechanisms have been postulated with a number of mediators identified. These include histamine, leukotrienes, proteases, neuropeptides, cytokines and opioids, which may activate peripheral itch-mediating C-fibres via receptors on the nerve terminals and central neuronal pathways. Therefore, there is no single universally effective anti-itch treatment available. First-line treatments for itch include topical therapies, such as emollients, mild cleansers (low pH), topical anaesthetics, steroids, calcineurin inhibitors and coolants (menthol). Treatment with systemic therapies can vary according to the aetiology of the chronic itch. Non-sedating antihistamines are helpful in conditions such as urticaria where the itch is primarily histamine mediated. Although the itch of eczema is not mediated by histamine, sedating antihistamines at night are helpful to break the itch-scratch cycle. Chronic itch may also be treated with other systemic therapies, such as anticonvulsants, antidepressants as well as mu-opioid antagonists, kappa-opioid agonists and phototherapy, depending on the cause of the itch. This article summarises the topical and systemic therapies available with our current understanding of the pathophysiology of itch.

Dermatitis. 2006 Mar;17(1):15-22.

Laser-assisted penetration of allergens for patch testing.

Veremis-Ley M, Ramirez H, Baron E, Hanneman K, Lankerani L, Scull H, Cooper KD, Nedorost ST.

University Hospitals of Cleveland/Case Western Reserve University, Cleveland, OH, USA.

BACKGROUND: Patch-test patients often complain of itching and inconvenience.

OBJECTIVE: To demonstrate (1) the usefulness of laser-assisted alteration of the stratum corneum to enhance allergen delivery and (2) patient satisfaction with this procedure.

METHODS: The LAD-01 (erbium:yttrium-aluminum-garnet) laser unit was used to alter stratum corneum from patients with known sensitivity to nickel or Kathon CG. These allergens were then applied to the laser-pretreated sites for 60 minutes. Results were observed at 24, 48, and 96 hours and at 1 week. One patient who refused conventional patch testing was tested with an entire modified North American standard series tray with the laser patch-test technique. An additional patient with previously demonstrated positive atopy patch-test reactions to environmental organisms was retested with laser pretreatment to the same antigens.

RESULTS: Three of three patients known to be sensitive to Kathon CG and eight of eleven known nickel-sensitive patients had positive reactions at the laser-pretreated sites. The patient who was tested with the entire standard series demonstrated relevant positive reactions to formaldehyde and to a textile resin. One subject with known reactions to three environmental organisms reproduced patch-test responses with laser pretreatment. No irritant reactions were noted. Patients reported no pain.

CONCLUSION: With further modification, laser pretreatment may improve patient convenience and decrease irritant test reactions owing to occlusion.

Acupunct Med. 2005 Mar;23(1):31-3.

The use of laser acupuncture for the treatment of neurogenic pruritus in a child–a case history.

Stellon A.

stellon@btinternet.com

This report describes the successful treatment using laser acupuncture of a six year old girl with neurogenic pruritus of the abdomen. It is the first case report of neurogenic pruritus treated by laser acupuncture. The main advantage of using low energy laser, as opposed to acupuncture needles, to stimulate points, is that low energy laser causes little or no sensation, which is particularly useful when treating children.

Burns. 2004 Jun;30(4):362-7.

Low Level Laser Therapy–a conservative approach to the burn scar?

Gaida K, Koller R, Isler C, Aytekin O, Al-Awami M, Meissl G, Frey M.

Department of Reconstructive and Plastic Surgery, Burn Unit, Division of Surgery, University of Vienna, Austria.

Burn scars are known to be difficult to treat because of their tendency to worsen with hypertrophy and contracture. Various experimental and clinical efforts have been made to alleviate their effects but the problem has not been solved. Since patients keep asking for Low Level Laser Therapy (LLLT) and believe in its effectiveness on burn scars, and since former studies show contradictory results of the influence of LLLT on wound healing, this prospective study was designed to objectify the effects of LLLT on burn scars. Nineteen patients with 19 burn scars were treated with a 400 mW 670 nm Softlaser twice a week over 8 weeks. In each patient a control area was defined, that was not irradiated. Parameters assessed were the Vancouver Scar Scale (VSS) for macroscopic evaluation and the Visual Analogue Scale (VAS) for pruritus and pain. Photographical and clinical assessments were recorded in all the patients. Seventeen out of 19 scars exhibited an improvement after treatment. The average rating on the VSS decreased from 7.10+/-2.13 to 4.68+/-2.05 points in the treated areas, whereas the VSS in the control areas decreased from 6.10+/-2.86 to 5.88+/-2.72. A correlation between scar duration and improvement through LLLT could be found. No negative effects of LLLT were reported. The present study shows that the 400 mW 670 nm softlaser has a positive, yet sometimes limited effect on burn scars concerning macroscopic appearance, pruritus, and pain.

Clin Exp Dermatol. 2003 Nov;28(6):595-6.

Rapid remission of severe pruritus from angiolymphoid hyperplasia with eosinophilia by pulsed dye laser therapy.

Nomura T, Sato-Matsumura KC, Kikuchi T, Abe M, Shimizu H.

Department of Dermatology, Hokkaido University Graduate School of Medicine, Sapporo, Japan.

A 48-year-old Japanese woman with angiolymphoid hyperplasia with eosinophilia (ALHE) was successfully treated with a flashlamp pulsed dye laser (585 nm, 450 micros pulse duration). The lesion was severely pruritic and had been enlarging slowly for 2 years but was resistant to conventional therapies, including topical, intralesional, and systemic corticosteroid, and cryotherapy. The severe pruritus immediately improved after the first treatment using the pulsed dye laser. The erythema and papules gradually improved without scarring and this was followed by further five treatments over approximately a 4-month interval. No clinical recurrences have been observed 1 year after completion of the treatment. We think that pulsed dye laser therapy is an effective treatment for ALHE in both Japanese as well as Caucasian patients. Pulsed dye laser therapy is also helpful in reducing the pruritus in ALHE patients.