Vol. 30. No. 2


Itch, which is defined as an unpleasant sensation of the skin that leads to the desire to scratch, has a profound negative effect on the quality of life of our patients. Although pruritus (itch) is the most frequent symptom in dermatology, it remains a major clinical challenge. Itch can be produced by various inflammatory skin diseases, allergies, tumors, autoimmune diseases, metabolic diseases, neuropathic states, and psychiatric disorders, as well as being a side effect from medications. Optimal treatment is often hampered by our lack of understanding of the pathophysiology, the crucial mediators, and the failure to identify “itch receptors.” Similar to pain, itch is a sensation that derives from activation of the sensory nervous system. Sensory nerve endings in the epidermis and dermis transmit the “itch signal” via the spinal cord and spinalthalamic tract to the central nervous system. The brain also appears to be a major player in the processing and chronicity of itch. Thus, the itch that patients perceive is an integrated perception modulated at 4 levels in the nervous system: first, in the periphery; second, in the dorsal root ganglia; third, at the spinal cord level; and fourth, in the brain. Basic science research has elucidated the levels at which antipruritic agents work and provides potential new targets for drug development. Clinical and basic science research on itch is a fascinating field for new discoveries. Recent discoveries, such as new histamine receptors, histamine-independent itch pathways, including gastrin-releasing peptide, proteases, and cytokines, illustrate that itch research has entered a new era. The development of new drugs, such as calcineurin inhibitors, slow-release local anesthetics, the -opiate receptor agonists, monoclonal antibodies targeting molecules involved in itch pathophysiology (eg, anti-immunoglobulin E, anti-nerve growth factor, anti-interleukin-4, anti-interleukin-31), substantiate the importance of itch in dermatology. We are delighted that, in this volume, we could bring together many of the key opinion leaders in the fields of basic and clinical “pruritology” to provide state-of-the-art reviews of the neuroanatomy and neurophysiology of peripheral and central itch. These articles are designed to help the practitioner understand the cellular and molecular basis of the itch that afflicts patients with various diseases, including atopic dermatitis and other inflammatory skin diseases, as well as systemic diseases, HIV, and cancer. We hope that this volume, which spans the basic and clinical science of pruritus, from bench to bedside, will give the reader greater insight into the pathogenesis of pruritus, and provides an approach for managing the itch patient in daily clinical practice.

Pruritus and Renal Failure

Martin Steinhoff, MD | Timothy G. Berger, MD

Patients with renal failure, usually end-stage renal disease (ESRD), commonly are afflicted
by severe pruritus. The pathogenesis of ESRD pruritus is unknown, but improving the
quality of dialysis can reduce the prevalence and severity of ESRD pruritus. Topical and
systemic agents as well as broadband ultraviolet phototherapy can be extremely beneficial.
Gabapentin has been recently discovered as an effective agent for the patient with ESRD
pruritus. Kappa opiate agonists are promising new therapeutic options.
Semin Cutan Med Surg 30:99-100 © 2011 Published by Elsevier Inc.


Approach to Pruritus in the Adult HIV-Positive Patient

Kieron Leslie, DTM&H, MRCP | Ser Ling Chua Serling, DTM&H, MRCP | Toby Maurer, MD

Pruritus will affect a majority of HIV-infected adults in the course of their disease, impacting
their quality of life. Itchy skin conditions in the HIV-infected patient may be atypical in
appearance and pose diagnostic and treatment challenges. Skin changes because of
chronic scratching or the absence of skin findings despite ongoing pruritus should prompt
investigations for underlying causes. The presence of pruritus or pruritic skin conditions
and their response to therapy may be a barometer for changes in systemic inflammation,
immune activation, and dysregulation because of infection with HIV and treatment with
antiretroviral therapy.
Semin Cutan Med Surg 30:101-106 © 2011 Elsevier Inc. All rights reserved.


Cancer and Itch

A. Nast, MD | Herbert C. Chiang, MD, PhD | Lynn A. Cornelius, MD | Victor Huang, MD

Itch represents a common and significant source of morbidity in the oncological setting.
Itch sometimes can be associated with an underlying malignancy, most commonly leukemia
or lymphoma. Alternatively, itch may present secondary to malignant invasion causing
hepatic or renal dysfunction. Finally, itch may be related to therapeutic regimens for the
underlying malignancy. This article seeks to review the clinical scenarios in which itch
affects the oncological patient, to briefly present the latest understanding of the molecular
and cellular mechanisms of malignancy-related itch, and to review currently available
therapeutic options.
Semin Cutan Med Surg 30:107-112 © 2011 Published by Elsevier Inc.


Pruritus in Elderly Patients—Eruptions of Senescence

Martin Steinhoff, MD | Timothy G. Berger, MD

Geriatric patients are frequently afflicted by pruritic dermatoses. Most pruritic elderly
patients present with a skin eruption. The high prevalence of pruritic inflammatory skin
disorders in elderly patients is a consequence of three physiological changes that occur
with aging: (1) the epidermal barrier repair is diminished; (2) the immune systems of elderly
patients are activated and have defective Th1 function along with enhanced Th2 function
(immunosenescense); and (3) neurodegenerative disorders may lead to pruritus by their
central or peripheral effects. These consequences of aging may all afflict the same patient,
explaining why elderly people often have multiple overlapping skin conditions. The following
article outlines the pathogenesis of the most common forms of pruritic skin disease in
elderly patients and the hallmarks that allow the dermatologist to establish an accurate
diagnosis and also suggests a management strategy for each common type of pruritic skin
disease in the elderly patient.
Semin Cutan Med Surg 30:113-117 © 2011 Published by Elsevier Inc.


Topical Therapies for Pruritus

Ethan A. Lerner, MD,PhD | Sarina B. Elmariah, MD, PhD

Itch, or pruritus, is the predominant symptom associated with acute and chronic cutaneous
disease, and in some cases may be debilitating. To date, there is no single universally
effective anti-itch treatment. Because the pathophysiology of itch in most cutaneous or
systemic disorders remains unclear, antipruritic therapy is often directed against a variety
of targets, including the epidermal barrier, immune system, or the nervous system. Topical
therapy is the mainstay of dermatologic management of acute or localized itch or in patients
with contraindications to systemic therapies. This review will summarize current topical
therapies to treat pruritus and discuss potential future therapies.
Semin Cutan Med Surg 30:118-126 © 2011 Elsevier Inc. All rights reserved.