Clinical classification of itch: a position paper of the International Forum for the Study of Itch

Chronic itch is a common and distressing symptom that arises from a variety of skin conditions and systemic diseases. Despite this, there is no clinically based classification of pruritic diseases to assist in the diagnosis and cost-effective medical care of patients with pruritus. The proposed classification focuses on clinical signs and distinguishes between diseases with and without primary or secondary skin lesions. Three groups of conditions are proposed: pruritus on diseased (inflamed) skin (group I), pruritus on non-diseased (non-inflamed) skin (group II), and pruritus presenting with severe chronic secondary scratch lesions, such as prurigo nodularis (group III). The next part classifies the underlying diseases according to different categories: dermatological diseases, systemic diseases including diseases of pregnancy and drug-induced pruritus, neurological and psychiatric diseases. In some patients more than one cause may account for pruritus (category "mixed") while in others no underlying disease can be identified (category "others"). This is the first version of a clinical classification worked out by the members of the International Forum for the Study of Itch. It is intended to serve as a diagnostic route for better evaluation of patients with chronic pruritus and aims to improve patients' care.     

Chronic generalized pruritus without primary skin lesions: a longitudinal prospective observational study

Pruritus is among the most common complaints in the field of dermatology. It is also a disturbing symptom of many systemic disorders. Chronic pruritus (CP) refers to the cases of the symptom which last longer than 6 weeks. We conducted a prospective analysis of patients with generalized pruritus without primary skin lesions. All patients underwent primary evaluations and then were followed from 12 to 18 months for further evaluations. Of the 5,127 patients referred to our dermatology clinic, 49 patients with generalized pruritus without primary skin lesions were evaluated. Most of the patients (44%) were in the age group of 40–60 years and female (58%). The duration of pruritus was 37.04 ± 30.4 weeks. Fifty percent of the patients with generalized pruritus had a systemic cause of pruritus. The most common underlying diseases were thyroid disorders (16.67%), diabetes mellitus (12.5%), and malignancy (8.33%). There were no significant statistical differences among the patients in terms of their age, gender, and disease duration with the underlying diseases (P = 0.47, P = 0.99, P = 0.816, respectively). However, the average age of the onset of pruritus was 12 years earlier in the women regardless of the underlying diseases (P = 0.011). Based on the findings of the study, we recommend considering endocrine disorders and malignancies as the most common underlying diseases leading to chronic pruritus without primary skin lesions.     

S2k Guidelines for the diagnosis and treatment of chronic pruritus – update – short version

Associated with a host of different diseases, pruritus is a cardinal symptom that poses an interdisciplinary diagnostic and therapeutic challenge. Over time, that symptom may progress independently of the initial cause, thus losing its function as a warning sign and turning into a clinically relevant disease of its own. In Germany, approximately 13.5 % of the general population are affected by chronic pruritus, with an incidence of 7 %. All forms of chronic pruritus require targeted treatment consisting of (a) diagnosis and management of the underlying disease, (b) dermatological treatment of primary or secondary (for example, dry skin, scratch lesions) symptoms, (c) symptomatic antipruritic treatment, and (d) psychological/psychotherapeutic treatment in case of an underlying or associated psychological or psychosomatic condition. Medical care of patients with chronic pruritus should therefore include an interdisciplinary approach, in particular with respect to diagnosis and therapy of the underlying disease as well as in terms of the management of treatment and adverse events. The objective of the present interdisciplinary guidelines is to define and standardize diagnostic and therapeutic procedures in patients with chronic pruritus. This is a short version of the current S2 guidelines on chronic pruritus. The long version may be found at www.awmf.org .     

HIV-associated pruritus: etiology and management

With the advent of highly active antiretroviral therapy (HAART), life-threatening opportunistic infection has become less common in patients with HIV infection and longevity has increased dramatically. With increased longevity, the problems of living with a chronic disease have become more prominent in this patient population. Disorders such as fat redistribution and metabolic abnormalities can result from antiviral medications and from HIV disease itself. Pruritus is one of the most common symptoms encountered in patients with HIV. The spectrum of skin diseases in such patients encompasses dermatoses of diverse etiologies; a few are peculiar to patients with HIV while others are not. Some of these conditions may cause severe and sometimes intractable pruritus that provokes scratching, picking, disfigurement, sleep loss, and significant psychological stress. Moreover, the expense of ongoing medical treatments can be daunting. Skin rash can sometimes be the initial presentation of HIV infection or serve as a harbinger of disease progression. Causes of pruritus include skin infections, infestations, papulosquamous disorders, photodermatitis, xerosis, drug reactions, and occasionally lymphoproliferative disorders. Drug eruptions are particularly common in patients who are HIV positive, presumably as a result of immune dysregulation, altered drug metabolism, and polypharmacy. Itching can also result from systemic diseases such as chronic renal failure, liver disease, or systemic lymphoma. Workup of pruritus should include a careful examination of the skin, hair, nails, and mucous membranes to establish a primary dermatologic diagnosis. If no dermatologic cause is found, a systemic cause or medication-related etiology should be sought. Idiopathic HIV pruritus is a diagnosis of exclusion and should only be considered when a specific diagnosis cannot be established. The management of HIV-associated pruritus should be directed at the underlying condition. Phototherapy has been found to be useful in the treatment of several HIV-associated dermatoses and idiopathic pruritus as well. Unfortunately, some of the treatments that have been suggested for patients with HIV are anecdotal or based on small uncontrolled studies. The last decade has seen a surge in the utilization of HAART which, to some degree, reconstitutes the immune system and ameliorates some dermatologic diseases. On the other hand, some skin diseases flare temporarily when HAART is started. Unless frank drug allergy is suspected, HAART does not need to be stopped.     

内脏恶性肿瘤在皮肤上的表现

本文报导自1980-1982年来所见的一些内脏恶性肿瘤在皮肤上的表现:(1)特异性皮损:结节功例、炎症浸润性斑块3例、淋巴水肿3例.(2)非特异性皮损:全身搔痒20例、红皮病5例、红斑2例、皮肌炎12例、黑棘皮病5例.特异性皮损中以结节为多见,凡见到诊断不明、难以归类的结节应疑及内脏恶性肿瘤转移的可能,活检有助于诊断.白血病患者可在临床症状缓解、周围血象好转时出现结节.非特异性皮损中以全身搔痒最为多见,凡老年人患原因不明的全身搔痒,久治不愈者,需考虑内脏恶性肿瘤的可能.     

Unexplained hypereosinophilia and the need for cytogenetic and molecular genetic analyses

BACKGROUND: Idiopathic hypereosinophilic syndrome (HES) is a diagnosis made after the exclusion of other causes of eosinophilia. However, differentiation of idiopathic HES from eosinophilic leukemia is sometimes difficult. In some cases, these diagnoses can be differentiated by cytogenetic or molecular findings, as illustrated in the patients described herein. OBSERVATIONS: We describe 3 patients with HES and associated pruritus; 1 patient also had recurrent lesions of eosinophilic cellulitis. All 3 patients were initially diagnosed as having idiopathic HES, but after evaluation and demonstration of molecular abnormalities, they were classified as having eosinophilic leukemia. CONCLUSIONS: Patients with a diagnosis of idiopathic HES should be evaluated for cytogenetic or molecular genetic abnormalities. These abnormalities can establish a diagnosis of chronic eosinophilic leukemia and may provide clues for emerging therapies.     

Functional itch disorder or psychogenic pruritus: suggested diagnosis criteria from the French psychodermatology group

Functional itch disorder or psychogenic pruritus is a poorly defined diagnosis. This paper sets out the proposed diagnostic criteria of the French Psychodermatology Group (FPDG). There are three compulsory criteria: localized or generalized pruritus sine materia, chronic pruritus (>6 weeks) and the absence of a somatic cause. Three additional criteria from the following seven items should also be present: a chronological relationship of pruritus with one or several life events that could have psychological repercussions; variations in intensity associated with stress; nocturnal variations; predominance during rest or inaction; associated psychological disorders; pruritus that could be improved by psychotropic drugs; and pruritus that could be improved by psychotherapies.     

Brachioradial pruritus in a patient with cervical disc herniation and Parsonage-Turner syndrome

Brachioradial pruritus is a chronic sensory neuropathy of unknown etiology which affects the skin of the shoulders, arms and forearms on the insertion of the brachioradialis muscle. We describe the case of a 60-yearold woman recently diagnosed with multiple myeloma who refers paresis, severe pruritus and itching lesions on the right arm with 6 months of evolution. Investigation led to a diagnosis of Brachioradial pruritus consequent to the presence of cervical disc herniation and Parsonage-Turner syndrome. The patient started gabapentin 900mg/day with good control of itching. Corticosteroids and antihistamines are often ineffective in the treatment of BP. Gabapentin has been used with encouraging results. All patients with Brachioradial pruritus should be evaluated for cervical spine injuries.     

Prurigo crónico: actualización

Chronic prurigo is itself a common condition, but it can also occur secondary to a large number of diseases. Management is challenging as historically chronic prurigo has been poorly defined and very few treatments are available. Clinically, it presents as excoriated, hyperkeratotic lesions. When chronic prurigo is suspected, a comprehensive differential diagnosis is essential. New diagnostic criteria have appeared in recent years and new drugs have been developed. Although no truly effective treatment is yet available, patients will benefit from a greater understanding of this condition.     

[Translated article] Update on Chronic Prurigo

Chronic prurigo is itself a common condition, but it can also occur secondary to a large number of diseases. Management is challenging as historically chronic prurigo has been poorly defined and very few treatments are available. Clinically, it presents as excoriated, hyperkeratotic lesions. When chronic prurigo is suspected, a comprehensive differential diagnosis is essential. New diagnostic criteria have appeared in recent years and new drugs have been developed. Although no truly effective treatment is yet available, patients will benefit from a greater understanding of this condition.     

Psychopharmakatherapie bei Pruritus

Pruritus represents one of the most bothersome symptoms of skin and internal diseases, and can also occur without an underlying detectable cause. It is well known that chronic pruritus seriously affects the quality of life in patients. The management of pruritus is challenging, especially if the underlying cause is not identifiable. Besides therapy with increased dosage of non-sedating H1-antihistamines, which is often not successful in severe pruritus, tri- or tetracyclic antidepressants and selective serotonin-reuptake inhibitors are recommended for therapy, as discussed in this review.     

银屑病的瘙痒特征及相关因素分析

目的调查银屑病患者中瘙痒发生率、瘙痒程度等临床特征及其影响瘙痒的相关因素。方法采用问卷调查的形式调查了112例银屑病患者,评价其瘙痒特征及影响瘙痒的相关因素。结果 112例银屑病患者中83%存在不同程度瘙痒,相关分析显示:患者瘙痒与否与年龄、疾病活动度呈显著相关(P0.05),而与患者性别、病程、家族史、吸烟、饮酒及身体质量指数(BMI)无相关性,瘙痒程度与银屑病皮损面积及严重程度指数(PASI)评分、浸润程度呈显著相关(P0.05),而与红斑、鳞屑无相关性。结论大多数银屑病患者存在不同程度的瘙痒症状,年纪越大、皮损越广泛、浸润程度越高以及处在进展期的银屑病患者瘙痒越剧烈。     

Chronic Pruritus in the Absence of Skin Disease: Pathophysiology,Diagnosis and Treatment

Chronic pruritus arises not only from dermatoses, but also, in up to half of cases, from extracutaneous origins. A multitude of systemic, neurological, psychiatric, and somatoform conditions are associated with pruritus in the absence of skin disease. Moreover, pruritus is a frequently observed side effect of many drugs. It is therefore difficult for physicians to make a correct diagnosis. Chronic pruritus patients frequently present to the dermatologist with skin lesions secondary to a long-lasting scratching behavior, such as lichenification and prurigo nodularis. A structured clinical history and physical examination are essential in order to evaluate the pruritus, along with systematic, medical history-adapted laboratory and radiological tests carried out according to the differential diagnosis. For therapeutic reasons, a symptomatic therapy should be promptly initiated parallel to the diagnostic procedures. Once the underlying factor(s) leading to the pruritus are identified, a targeted therapy should be implemented. Importantly, the treatment of accompanying disorders such as sleep disturbances or mental symptoms should be taken into consideration. Even after successful treatment of the underlying cause, pruritus may persist, likely due to chronicity processes including peripheral and central sensitization or impaired inhibition at spinal level. A vast arsenal of topical and systemic agents targeting these pathophysiological mechanisms has been used to deter further chronicity. The therapeutic options currently available are, however, still insufficient for many patients. Thus, future studies aiming to unveil the complex mechanisms underlying chronic pruritus and develop new therapeutic agents are urgently needed.     

Two Clinically Unusual Cases of Folliculotropic Mycosis Fungoides: One with and the Other without Syringotropism

Mycosis fungoides is the most common form of cutaneous T-cell lymphoma, and it rarely exhibits predilection for hair follicle and eccrine gland infiltration. Here, we present 2 similar cases that display folliculotropism with varying amounts of follicular mucinosis, with and without syringotropism. The features observed in both cases were cystic, comedo-like, acneiform lesions; generalized involvement with loss of body hair; pruritus; and hidradenitis suppurativa-like lesions. Hypohidrosis as well as nail and palmoplantar involvement with lichen planopilaris-like clinical features were unique characteristics of the first case. Despite the well-known aggressive behavior of follicular mycosis fungoides, the presented cases had a subtle, slowly progressive, but persistent, clinical course. Folliculotropic and syringotropic mycosis fungoides are variants of cutaneous T-cell lymphoma. Clinical presentations might be challenging, and multiple, deep biopsy specimens containing adnexal structures are required for this critical diagnosis. Aggressive treatment may not be necessary in cases having an indolent course, especially in those with syringotropism.     

How to define chronic prurigo?

Chronic prurigo impairs quality of life and is immensely challenging to treat. Until recently, no clear definition or classification system was available for this disease. A European task force specialized in pruritus defined chronic prurigo as a distinct disease characterized by chronic pruritus, a lengthy scratching behaviour and the presence of pruriginous lesions. Papular, nodular, plaque, umbilicated and linear prurigo were identified as clinical subtypes according to the most prominent lesion type observed in the physical examination. Various clinical and pathophysiological aspects, which are common across the range of clinical manifestations of chronic prurigo, argue for chronic prurigo as a disease in its own right. Chronic prurigo should be clearly demarcated from other conditions such as so‐called acute or subacute prurigo forms as well as from psychogenic self‐inflicted skin lesions, since different diagnostic criteria apply for these diseases. This viewpoint essay provides a detailed definition and classification of chronic prurigo including its obligatory and associated diagnostic criteria and discusses chronic prurigo as a distinct disease as well as the demarcation to other relevant conditions.     

Transcutaneous electronic nerve stimulation in the treatment of generalized pruritus

Generalized pruritus is a notoriously troublesome condition for both patient and dermatologist. This paper describes the favourable therapeutic effect of transcutancous electrical nerve stimulation (TENS) in two elderly patients with severe chronic generalized pruritus unresponsive to other treatment. The therapeutic application of TENS to the treatment of generalized pruritus has not previously been described.     

Clinical management of pruritus

The care of patients with chronic pruritus as a symptom of a wide variety of underlying diseases continues to confront dermatologists with diagnostic and therapeutic challenges. However, a structured history and a physical examination may already substantially help in narrowing down the number of potential differential diagnoses. Apart form reducing the intensity of pruritus, identification and appropriate treatment of the underlying disease are important needs of patients. If these goals doesn't lead to improvement of itch, current guidelines provide a number of topical and systemic therapies for symptomatic treatment. Various skin lesions (for example, xerosis caused by irritant substances, secondary scratch lesions) prompt patients to consult a dermatologist, but most cases require an interdisciplinary therapeutic approach to identify potential internal medicine, neurologic, or psychosomatic aspects. Although great strides have been made in basic research, specific therapies are still rare, and a precise knowledge of the legal framework for the implementation of guidelines (for example, off‐label use) is essential. This CME article gives an overview of the causes of and treatment options for chronic pruritus and discusses both advances in basic research as well as progress in clinical knowledge.