Itch is the most frequent symptom in dermatology and has been researched more extensively in recent years. Nevertheless, there are few true epidemiological studies on itch. The aim of this paper is to review the current state of research on the epidemiology of chronic itch in Western and non-Western populations. The electronic databases PubMed, Medline and the Cochrane Library were searched. Conference proceedings and national and international studies were included. It is difficult to compare existing studies due to differing methodology and lack of standardized measures. The symptom of itch is a challenge, not only to clinicians, but also within the structure of regional health systems, and with regards to accessibility to specialized medical doctors in non-Western countries. Published studies show that the symptom of itch is highly prevalent; it should therefore receive adequate attention from physicians and other healthcare providers, including healthcare planners.

Epidemiology of itch: adding to the burden of skin morbidity.

Understanding Pruritus in Systemic Disease

Receptors, cells and circuits involved in pruritus of systemic disorders.

The history, neurophysiology, clinical aspects and treatment of pruritus are reviewed in this article. The different forms of pruritus in dermatological and systemic diseases are described, and the various aetiologies and pathophysiology of pruritus in systemic diseases are discussed. Lack of understanding of the neurophysiology and pathophysiology of pruritus has hampered the development of adequate therapies. Nevertheless, the discovery of primary afferent neurons and, presumably, second-order neurons with typical histamine responses mediating pruritic sensations can be regarded as a breakthrough in our understanding of the mechanisms behind pruritus. The number of experimental and therapeutic studies has greatly increased during the past few years, reflecting an increased interest in this topic. However, further effort is needed to develop new therapeutic concepts and clarify some confusion arising from promising case reports and uncontrolled clinical studies. A precise work-up for evaluating patients with pruritus is proposed, which may help the physician to identify the underlying causes and thus to treat the patient appropriately.

Pruritus: A Review

Cutaneous manifestations of diabetes mellitus

Three hundred diabetic and 100 nondiabetic hospital outpatients (both groups of comparable age and sex distribution) were assessed for the presence of generalized and localized pruritus. Pruritus vulvae was significantly more common in diabetic women (18.4%) than in controls (5.6%) and was significantly associated with poor diabetes control (mean glycosylated hemoglobin level less than 12%). Other forms of localized pruritus were equally common in diabetic and nondiabetic patients, regardless of glycosylated hemoglobin levels. Generalized pruritus was present in 14 diabetic patients, but in 5 cases the symptom was ascribed to intercurrent illness or drug administration. Thus, generalized pruritus without apparent cause was present in only 8 diabetic patients (2.7%) and was not significantly more common than in nondiabetic patients. It is doubtful if diabetes mellitus per se should be regarded as a cause of generalized or localized pruritus, other than pruritus vulvae.

J B Neilly

Papers

Pruritus in diabetes mellitus: investigation of prevalence and correlation with diabetes control.