Pruritus

Ohne Zusammenfassung     

Pruritus

Health-related quality of life (QoL) is a patient-reported outcome that describes the impact of the disease in question to all aspects of persons' life, including psychosocial, emotional, physical, and functional impact. As such, health-related QoL is particularly relevant in conditions that have no physical signs and need to rely on patient reports to know whether they are improving or not. Work is beginning in pruritus to develop instruments that can measure pruritus-related QoL. This article reviews the instruments that have been developed and used in pruritus and also reviews the literature regarding the impact of pruritus on QoL.     

Generalized Pruritus

Background:Generalized pruritus can often be the primary manifestation of systemic disease. Objective:To determine how frequently generalized pruritus had a systemic etiology in an outpatient population seen in a dermatology department and whether any identifiable patient characteristics meant a systemic explanation of generalized pruritus was more likely. Methods:A prospective controlled study of 55 patients with generalized pruritus and 41 healthy age- and sex-matched control subjects. Clinical data were collected from patients and laboratory parameters investigated in both patients and healthy control subjects to determine the frequency of systemic disease in each group. Results: Of 55 patients, 12 had a systemic cause of pruritus. Pruritus was the initial symptom of systemic disease in eight of these patients. The underlying diseases included hypothyroidism, chronic lymphocytic leukemia, hepatitis C, hepatitis B, diabetes mellitus, lung cancer, uremia, and iron deficiency anemia. Of these, iron deficiency anemia was the most common cause. Compared with the control group, mean serum hemoglobin, iron, and cyanocobalamin (vitamin B₁₂) levels in patients with generalized pruritus were lower. No other patient characteristics were statistically associated with systemic causes of pruritus. Conclusion:Generalized pruritus was the initial symptom of a systemic disease in 8 of 55 patients presenting to a dermatology outpatient clinic with this complaint. A number of underlying diseases were identified, of which the most common was iron deficiency anemia.     

Pruritus ani

In the anal region, pruritus may be both idiopathic (mainly of psychological/psychiatric origin) and secondary to an underlying disorder or related to local causes (mainly of dermatologic interest). Persistent pruritus ani is, in particular, a challenging experience for the dermatologist.     

Cholestatischer Pruritus

Pruritus is a common symptom of hepatobiliary disorders and may considerably diminish quality of life. Cholestatic pruritus exerts a circadian rhythm and is typically most severe in the evening hours and early at night. Itching is reported often to be most intense at the palms and the soles, but may also be generalized. The pathophysiological mechanisms of cholestatic pruritus have not been completely clarified. In the past, bile salts, histamine, progesterone metabolites and opioids have been discussed as potential causal substances; a correlation with itch intensity could never be proven. The enzyme autotaxin, which releases lysophosphatidic acid, has recently been identified as potential cholestatic pruritogen. Treatment aims to bind pruritogens in the gut lumen by resins such as cholestyramine, to modulate pruritogen metabolism by rifampicin and to influence central itch signaling by μ-opioid antagonists and selective serotonin re-uptake inhibitors. In cases of refractory pruritus experimental treatment options such as UV-therapy, extracorporeal albumin dialysis and nasobiliary drainage may be considered.     

Brachioradialer Pruritus

We report on a female patient with brachioradial pruritus, in whom the cause could be verified by purposeful diagnostics (e. g., MRI). The clinical symptoms with localized itching result from circumscribed nerve root compression and hyperexcitation of the nerve fibers. Under treatment with gabapentin, an anticonvulsant with a very good analgesic and good antipruritic effect, the itch ceased and the skin changes healed. This case shows that this special form of neuropathic itch requires targeted therapy, which apart from symptomatic treatment should primarily focus on remedying the cause, if feasible.     

Crotamiton Lotion in Pruritus

The authors studied the antipruritic effects of 10% crotamiton lotion in 31 patients with bilaterally symmetrical pruritic dermatoses. In this double-blind, paired-comparison clinical trial, there was no significant difference in relief of pruritus between the crotamiton lotion and its vehicle. The study does not confirm the results of previous uncontrolled studies indicating that crotamiton has an antipruritic effect.     

Chronischer Pruritus

Chronic pruritus (starting from 6 weeks duration) is symptom of dermatological, internal, neurological or psychiatric disease. Identification and treatment of the underlying diseases is of great importance especially in the initial phase of chronic pruritus in order to prevent peripheral and central sensitization processes and thus chronification. Application of the redefined clinical classification, newly defined clinical algorithms and inquiry of clinical characteristics of pruritus is helpful in finding the underlying disease. In chronic pruritus existing for several years, clarifying the underlying origin is difficult and therapies are often ineffective. Next to conventional therapies such as antihistamines and corticosteroids, central effective substances can be applied preventing pruritus sensation on spinal or cerebral level.     

Chronischer Pruritus

Chronic pruritus is a highly prevalent, multifactorial symptom requiring extensive diagnostics, treatment and consideration of accompanying symptoms (reduced quality of life, sleep disorders, psychic factors). Patient care is thus complex and requires consideration of individual treatment goals. Patients indicate their wish for a symptom-free life an explanation of the causes and a trustful physician–patient relationship. The targeted use of questionnaires is thus advisable in order to structurally survey the history, pruritus intensity, quality of life and treatment progression. Nevertheless, there are many administrative and economical hurdles in the health care system to overcome in order to provide patients with chronic pruritus the best possible care, also per the recommended guidelines. The development of specialized centers and training courses for medical practitioners is thus urgently needed.     

Arzneimittelinduzierter Pruritus

Background

Pruritus, especially chronic pruritus, has long been underestimated and leads to high psychological strain in the affected patients. Even today, in spite of receiving increased attention, the underlying etiology cannot always be identified.

Methods

We review potential underlying pathologic mechanisms of drug-induced pruritus, focusing among others on current dermato-oncological medications in terms of their pruritogenic risks.

Results

Acute pruritus must be distinguished from chronic pruritus which lasts for a minimum of 6 weeks. There are various therapeutic approaches for drug-induced pruritus. As a first step, the drug causing the pruritus has to be identified; then the intake of that drug has to be ceased or modified. This may not always be possible, as in the case of chemotherapy agents.

Conclusions

With regard to the demographic development of the population with increasing life expectancy and the resulting increasing polypharmacy, drugs will have to be taken into account as a possible cause for pruritus more often in the future. It would be desirable to routinely assess pruritus as a possible adverse effect in regulatory drug studies.     

Pruritus in der Schwangerschaft

Pruritus is the leading dermatological symptom during pregnancy. Besides preexisting or acquired dermatoses, there are a number of pregnancy-specific dermatological diseases such as PEP (polymorphic eruption of pregnancy, previously named PUPPP), pemphigoid (herpes) gestationis, and pruritus gravidarum that are accompanied by severe itching and scratching. Because of potential effects on the fetus, the treatment of pruritus in pregnancy requires prudent consideration. The use of topical and systemic treatments depends on the underlying aetiology of pruritus and the stage and status of the skin. In general, emollients, topical anti-pruritics and topical corticosteroids appear to be the safest options for localised forms of pruritus in pregnancy whereas systemic treatments and/or UV phototherapy are adequate for generalized pruritus. Systemic corticosteroids and a restricted number of antihistamines may be administered in severe cases. This paper highlights the major aetiologies of pruritus during pregnancy and points out the cornerstones of antipruritic therapy in recognition of our own clinical experiences and the current literature.     

Pruritus in adult dermatomyositis

Dermatomyositis has a significant clinical component of pruritus that has not yet been studied. Pruritus can significantly affect the life of patients. The aim of the present work was to study the degree of pruritus experienced by patients. A four-question survey was sent to patients with documented dermatomyositis. The survey used a 100-mm Visual Analogue Scale (VAS) to describe current, worst and daily pruritus, and the effect this has on daily activities. Twenty-six subjects returned completed questionnaires: four had no pruritus; the majority had a significant amount with means above 50 on the VAS. A mean of 44.6 was found for the effect on daily life. Further studies should be performed to examine the prevalence and severity of pruritus in this population and it's effect on their quality of life. Clinicians must be aware of the significant pruritus and provide adequate therapy to improve quality of life.