Antipruritic and thermal sensation effects of hydrocortisone creams in human skin

Autoreactive Peripheral Blood T Helper Cell Responses in Bullous Pemphigoid and Elderly Patients With Pruritic Disorders

Bullous pemphigoid (BP) is a prototypic autoimmune disorder of the elderly, characterized by serum IgG autoantibodies, namely anti-BP180 and anti-BP230, directed against components of the basal membrane zone that lead to sub-epidermal loss of adhesion. Pruritus may be indicative of a pre-clinical stage of BP, since a subset of these patients shows serum IgG autoantibodies against BP230 and/or BP180 while chronic pruritus is increasingly common in the elderly population and is associated with a variety of dermatoses. Clinical and experimental evidence further suggests that pruritus of the elderly may be linked to autoimmunity with loss of self-tolerance against cutaneous autoantigens. Thus, the objective of this study was to determine autoreactive T cell responses against BP180 in elderly patients in comparison to patients with BP. A total of 22 elderly patients with pruritic disorders, 34 patients with bullous or non-bullous BP and 34 age-matched healthy controls were included in this study. The level of anti-BP180 and anti-BP230 IgG serum autoantibodies, Bullous Pemphigoid Disease Area Index (BPDAI), and pruritus severity were assessed for all patients and controls. For characterization of the autoreactive T cell response, peripheral blood mononuclear cells were stimulated ex vivo with recombinant BP180 proteins (NH2- and COOH-terminal domains) and the frequencies of BP180-specific T cells producing interferon-γ, interleukin (IL)-5 or IL-17 were subsequently determined by ELISpot assay. Patients with BP showed a mixed Th1/Th2 response against BP180 while autoreactive Th1 cells were identified in a minor subset of elderly patients with pruritic disorders. Furthermore, our T cell characterization revealed that therapeutic application of topical clobetasol propionate ointment in BP patients significantly reduced peripheral blood BP180-specific T cells, along with clinically improved symptoms, strongly suggesting a systemic immunosuppressive effect of this treatment.

Scalp Pruritus: Review of the Pathogenesis, Diagnosis, and Management

Scalp pruritus is a frequent problem encountered in dermatological practice. This disorder is caused by various underlying diseases and is a diagnostic and therapeutic challenge. Scalp pruritus may be localized to the scalp or extended to other body areas. It is sometimes not only associated with skin diseases or specific skin changes, but also associated with lesions secondary to rubbing or scratching. Moreover, scalp pruritus may be difficult to diagnose and manage and may have a great impact on the quality of life of patients. It can be classified as dermatologic, neuropathic, systemic, and psychogenic scalp pruritus based on the potential underlying disease. A thorough evaluation of patients presenting with scalp pruritus is important. Taking history and performing physical examination and further investigations are essential for diagnosis. Therapeutic strategy comprises removal of the aggravating factors and appropriate treatment of the underlying condition. All treatments should be performed considering an individual approach. This review article focuses on the understanding of the pathophysiology and the diagnostic and therapeutic management of scalp pruritus.

[Therapy of prurigo nodularis]

Treatment of prurigo nodularis is a challenge. No specific therapies are approved and data from clinical trials are rare. Based on our experience, case series, randomized controlled trials as well as the S2k guideline on chronic pruritus, we provide general principles and specific recommendations in this review.

Current topical and systemic therapies for itch

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.

Magistral formulations and pruritus therapy - What is established, what is confirmed, what is new?

Pruritus is a common symptom encountered by many different specialties. One must clinically differentiate between pruritus associated with skin disease or inflammation and pruritus with normal skin. Searching for possible underlying diseases is indispensable, because pruritus can be very chronic and has multiple pathogenetic mechanisms. Therapy – especially topical therapy – is difficult and often not successful. Very often systemic treatment has to be combined with topical approaches, considering both the active ingredients and appropriate vehicles. There are still open therapeutic gaps in the pharmaceutical product market, which can partially be resolved by using standard prescriptions for formulations. Due to the new pharmacy practice order, standardized compounded formulations should be given preference, since individual formulations often do not pass the plausibility check of the compounding pharmacist. Also the use of cosmetic ingredients (by example, commercial cold creams) is no longer permitted, since only ingredients with pharmaceutical quality can be used in compounding. We will show – based on practical cases – different therapeutic options for treatment with standardized magistral formulations from the NRF (New German Pharmacopoeia for compounded medications).

Chronic pruritus: clinics and treatment

Chronic pruritus, one of the main symptoms in dermatology, is often intractable and has a high impact on patient's quality of life. Beyond dermatologic disorders, chronic pruritus is associated with systemic, neurologic as well as psychologic diseases. The pathogenesis of acute and chronic (>6 weeks duration) pruritus is complex and involves in the skin a network of resident (e.g., sensory neurons) and transient inflammatory cells (e.g., lymphocytes). In the skin, several classes of histamine-sensitive or histamine-insensitve C-fibers are involved in itch transmission. Specific receptors have been discovered on cutaneous and spinal neurons to be exclusively involved in the processing of pruritic signals. Chronic pruritus is notoriously difficult to treat. Newer insights into the underlying pathogenesis of pruritus have enabled novel treatment approaches that target the pruritus-specific pathophysiological mechanism. For example, neurokinin-1 antagonists have been found to relieve chronic pruritus.

Therapy of pruritus

IMPORTANCE OF THE FIELD

Pruritus is the predominant symptom of skin disease. Owing to the poorly understood pathophysiology, the development of effective treatment modalities for pruritus has proven to be particularly difficult. At present, there is no universally accepted therapy for itch. The purpose of this review is to provide an update on the treatment of pruritus.

AREAS COVERED IN THIS REVIEW

An overview of current, emerging and possible future therapies for pruritus is provided.

WHAT THE READER WILL GAIN

Insights into possible treatment regimes for pruritus in different clinical scenarios.

TAKE HOME MESSAGE

The therapy of pruritus is challenging and at present takes on an individualistic approach. Recent advancements in the mechanisms that underlie this distressing symptom have identified new targets for future therapy.

Evaluation of chronic pruritus in older patients

Chronic pruritus, one of the main symptoms in dermatologic diseases, is often intractable and has a high impact on a patient´s quality of life. In addition to dermatologic disorders, chronic pruritus is associated with systemic and neurologic, as well as psychologic, diseases. Aging skin is considered to be more susceptible to pruritic disorders. Thus, owing to demographic changes, pruritus is becoming more prevalent. The elderly are often afflicted with comorbidities and polypharmacy, which can complicate diagnosis and therapy. In this review we present a rational work-up adapted to the special premises and needs of geriatric patients. This may facilitate the choice of suitable therapeutic regimens.

Severity of disease, rather than xerosis, correlates with pruritus in patients with atopic dermatitis

BACKGROUND

Atopic dermatitis (AD) is a chronic, relapsing skin disease characterized by xerosis and pruritus. As pruritus is an unpleasant sensation and the associated scratching aggravates the skin eruption considerably, it is important to control this symptom when treating AD. Dry skin is generally considered to be a potential cause of pruritus in xerotic skin diseases, but a clear correlation between pruritus and atopic xerosis has not been demonstrated. Aim To examine the contribution of atopic xerosis to the development of pruritus in AD.

METHODS

Twenty-two patients with AD (12 males and 10 females; mean age, 27.5 years) were examined. Xerosis and the severity of disease were evaluated using the Objective Severity Assessment of Atopic Dermatitis (OSAAD) and the SCORing Atopic Dermatitis (SCORAD) index, respectively. A modified SCORAD index was calculated by removing the symptoms potentially associated with pruritus (intensity of itching and insomnia) from the standard SCORAD index. Pruritus was evaluated using both a visual analog scale and the Verbal Itch Score.

RESULTS

The severity of AD (modified SCORAD index) correlated better than atopic xerosis (OSAAD score) with both pruritus scores, possibly indicating that the use of appropriate anti-inflammatory agents may be helpful in controlling pruritus as well as skin eruption in AD.

CONCLUSION

Our data suggest that the severity of disease (or skin inflammation) provides a greater contribution than xerosis to the development of pruritus in AD.

Dermal mast cells play a central role in the incidence of scratching behavior in mice induced by multiple application of the hapten, 2,4,6-trinitrochlorobenzene

Repeated application of 1% 2,4,6-trinitrochlorobenzene (TNCB) in acetone solution causes chronic skin inflammation in BALB/c mice. Associated scratching behavior gradually appeared, and chronic scratching behavior was established over 40 days after the initial application of TNCB. In order to explore the possible involvement of T cells and mast cells in the appearance of pruritus, we examined the response of athymic nude mice and genetically mast-cell-deficient mice. We could not detect either severe skin inflammation or immunoglobulin (Ig)E production in T-cell-deficient BALB/c nu/nu mice even after 80 days of TNCB treatment, whereas typical severe skin inflammation and IgE production were observed in mast-cell-deficient WBB6F1-W/Wv and WBB6F1-Sl/Sld mice. Furthermore, we observed persistent scratching behavior in WBB6F1-W/Wv mice, but not in BALB/c nu/nu and WBB6F1-Sl/Sld mice. Histological examination of TNCB-treated animals revealed the development of dermal mast cells in W/Wv mice but not in Sl/Sld mice. Degranulation of dermal mast cells was observed in the WBB6F1-W/Wv genotype, but most mast cells remained intact in TNCB-treated BALB/c nu/nu mice. These results suggest that mast cells play a pivotal role in the incidence of scratching behavior in this chronic pruritus model.

Over-the-counter topical antipruritic agents are commonly recommended by office-based physicians: an analysis of US practice patterns

BACKGROUND

Pruritus is one of the most common complaints among patients who visit physicians. Over-the-counter topical antipruritic medications are widely recommended by physicians and are self-administered by patients for the treatment of pruritus. However, there are few scientific controlled studies evaluating the effect of these drugs on pruritus.

OBJECTIVES

To assess the role of physician-recommended over-the-counter medications for the treatment of pruritus.

METHODS

Records were analyzed for office-based physician visits in which over-the-counter antipruritic topical medications were recommended in the National Ambulatory Medical Care Survey between the years 1995 and 2000.

RESULTS

The largest proportion of over-the-counter antipruritic agent recommendations were during visits to dermatologists, accounting for 41% of all such recommendations. Other physicians that recommended such agents included family physicians and pediatricians, accounting respectively for 26% and 21% of the recommendations. The most commonly recommended over-the-counter medications included hydrocortisone preparations (72%) and diphenhydramine (15%). Over-the-counter medications were more frequently recommended in the pediatric age group.

CONCLUSION

This study demonstrates that over-the-counter medications are frequently recommended for the treatment of pruritus.

Pruritic dermatoses: overview of etiology and therapy

This review begins with a brief survey of the neurophysiology and neuroanatomy of pruritus, and goes on to describe the etiology of the major allergic and nonallergic pruritic disorders. The etiology of pruritus often suggests the appropriate treatment. For example, urticaria, which is primarily mediated by histamine, is amenable to treatment with H1 antihistamines. Second-generation, nonsedating antihistamines appear to be more effective than sedating antihistamines, perhaps because of better compliance. Other systemic pharmacologic options may be useful in nonhistamine-mediated disorders, for example, immunomodulators for inflammation-induced pruritus or opiate antagonists for atopic dermatitis. Nonpharmacologic measures, such as proper skin care, and physical modalities, such as phototherapy or acupuncture, may also be helpful.

Screening topical antipruritics: a histamine-induced itch human model

Itch is a subjective symptom; its magnitude (intensity) may be only estimated by the reports of patients or volunteers. We utilized a comparative screening method to identify and quantify the efficacy of topical antipruritics with a histamine-induced itch human model. Ten individuals responsive to histamine-induced itch sensation were enrolled. Both forearms served as test sites. Each test site was treated randomly either by histamine injection only or pretreated with a coded candidate formula for 30 min and then a histamine injection. Itch was experimentally induced in each test site by the intracutaneous injection of 100 microg histamine dihydrochloride dissolved in 1 ml normal saline. Itch magnitude was measured each minute after histamine injection for 20 min with a magnitude visual analogue scale. Itch duration was also recorded. Formulation D significantly (p < 0.05) decreased itch magnitude (within a 20-min test period), from 2.6 +/- 2.1 cm (mean +/- SD) to 2.2 +/- 2.1 cm (mean +/- SD) when compared to its vehicle control; it also significantly (p < 0.05) shortened itch duration (15.0 +/- 7.4 min; mean +/- SD) in comparison with its vehicle control (20.3 +/- 7.0 min; mean +/- SD). Of all the formulations tested, formulation D was the most effective antipruritic in decreasing histamine-induced itch. This method may act as a simple and robust screening procedure when evaluating potential antipruritics and allow a comparison among products. Until validated with disease-induced itch, e.g., atopic dermatitis, the model should be considered screening in nature.