[Eosinophilic dermatoses]

Eosinophilic dermatoses are a heterogeneous group of rare diseases that histopathologically display the defining pattern of an eosinophil-rich dermal infiltrate. In these eosinophilic dermatoses, a histopathologic pattern called flame figures, which result from degranulation of eosinophils in the tissue, can be observed. Although eosinophil granulocytes can also be detected in other dermatoses such as atopic dermatitis, urticaria, prurigo and bullous pemphigoid, the eosinophil-rich infiltrate is decisive for classic eosinophilic dermatoses. Accordingly, eosinophilic dermatoses include hypereosinophilic syndrome, eosinophilic fasciitis, granuloma faciale, pustular sterile eosinophilia, and angiolymphoid hyperplasia with eosinophilia. These eosinophilic dermatoses display clinical different patterns and are discussed in this article, as well as the interesting eosinophils and novel therapeutic options.

Novel functions of S1P in chronic itchy and inflammatory skin diseases

S1P is a pleotropic sphingolipid signalling molecule that acts through binding to five high-affinity G-protein coupled receptors. S1P-signaling affects cell fate in a multitude of ways, e.g. influencing cell differentiation, proliferation, and apoptosis, as well as playing an important role in immune cell trafficking. Though many effects of S1P-signaling in the human body have been discovered, the full range of functions is yet to be understood. For inflammatory skin diseases such as atopic dermatitis and psoriasis, evidence is emerging that dysfunction and imbalance of the S1P-axis is a contributing factor. Multiple studies investigating the efficacy of S1PR modulators in alleviating the severity and symptoms of skin conditions in various animal models and human clinical trials have shown promising results and validated the interest in the S1P-axis as a potential therapeutic target. Even though the involvement of S1P-signalling in inflammatory skin diseases still requires further clarification, the implications of the recent findings may prompt expansion of research to additional skin conditions and more S1P-axis modulatory pharmaceuticals.

Struktur der Hautkliniken und dermatologische Lehre in den neuen Universitäten in Deutschland

Im Zuge der Neugründung medizinischer Fakultäten in Deutschland muss auch die dermatologische Forschung und Lehre aufgebaut werden. Diese großen Zusatzaufgaben neben der Krankenversorgung stellen eine Herausforderung für die Klinikleitungen dar. In diesem Übersichtsbeitrag beschreiben exemplarisch Chefärztinnen und Chefärzte neuer Universitätshautkliniken und dermatologischer Fachabteilungen die Auswirkungen, die die Umwandlung in eine Universitätsklinik auf die Forschung und Lehre sowie den klinischen Alltag mit sich gebracht hat.

Wie wird man Uniklinikum? Neue Wege des Medizinstudiums in Deutschland

Die Nachfrage nach Studienplätzen der Humanmedizin übersteigt seit vielen Jahren deutlich das Angebot der staatlichen Medizinfakultäten in Deutschland. Durch den zunehmenden Ärztemangel steigt auf der anderen Seite der Bedarf an ausgebildeten Medizinerinnen und Medizinern. Um diese Lücke zu schließen, wurden in den letzten Jahren zahlreiche Möglichkeiten neu eröffnet, in Deutschland Humanmedizin zu studieren. Neben Neugründungen von Fakultäten sind insbesondere Kooperationen von Kliniken mit europäischen Universitäten und Privatuniversitäten zu nennen. Dieser Beitrag gibt eine Übersicht über die Optionen und Rahmenbedingungen.

IgE autoantibodies in serum and skin of non-bullous and bullous pemphigoid patients

BACKGROUND

Non-bullous pemphigoid (NBP) is a pemphigoid variant which frequently resembles other pruritic skin diseases. In contrast with bullous pemphigoid (BP), blisters are absent. In BP, previous studies showed that IgE autoantibodies may be involved in its pathogenesis. IgE-activated mast cells, basophils and eosinophils may participate in BP by inducing pruritus and possibly blister formation, although the differential role of IgE in NBP compared with BP has not yet been described.

OBJECTIVE

To assess IgE in serum and skin of NBP and BP patients.

METHODS

We examined total IgE and pemphigoid-specific IgE in the serum of 68 NBP and 50 BP patients by enzyme-linked immunosorbent assay (ELISA). Sera of 25 pemphigus patients and 25 elderly patients with pruritus were included as controls. Skin biopsies of 14 NBP and 14 BP patients with the highest IgE titres to NC16A were stained for IgE by immunofluorescence techniques.

RESULTS

Total IgE was elevated in 63% of NBP and 60% of BP patients, and in 20% of pemphigus controls, as well as 60% of elderly controls. IgE ELISAs were more frequently positive in BP than in NBP (NC16A 18% vs. 9%, P = 0.139; BP230 34% vs. 22%, P = 0.149). IgE ELISAs for NC16A and BP230 were positive in 8% and 20% of elderly controls, respectively, while all pemphigus controls were negative. Two of 28 biopsies (7%; one NBP, one BP) showed linear IgE along the basement membrane zone, while in most biopsies (71% NBP; 86% BP) IgE was bound to dermal cells.

CONCLUSION

Since IgE was present in the serum and skin of both NBP and BP patients, this supports IgE-dependent mechanisms common to both diseases, such as pruritus. However, it remains to be elucidated whether IgE contributes to blister formation in BP.

Neurological disorders are associated with bullous pemphigoid

BACKGROUND

Bullous pemphigoid (BP) is the most common subepidermal autoimmune blistering disease with an increased incidence particularly among the elderly. Several studies have recently reported an association between BP and neurological disorders.

OBJECTIVE

To evaluate the association between BP and neurological disorders in a single centre in Germany.

METHODS

We retrospectively assessed 183 patients with BP (diagnosed between 2011 and 2015) and 348 age- and sex-matched controls for neurological disorders. The latter were confirmed either by a neurologist or psychiatrist.

RESULTS

Overall, there was a highly statistically significant association between BP and neurological disorders (P < 0.0001). These included dementia (P < 0.0001), Parkinson`s disease (P = 0.0434), stroke (P = 0.0015) and other neurological disorders but not Alzheimer's diseases, which was more common among patients in the control group.

CONCLUSION

Our cohort of bullous pemphigoid and neurological disorders demonstrates a significant association between bullous pemphigoid and neurological disorders, including dementia, Parkinson's disease and stroke. These observations support the need for future studies in order to elucidate the immunological mechanisms responsible for these comorbidities.

[Neurophysiology of atopic pruritus]

Pruritus is one of the major symptoms of inflammatory skin diseases and strongly affects the quality of life in patients. Although the perception of pruritus and pain are closely intertwined, pruritus represents a distinct sensation, which is also significantly different to pain at a neurophysiological level. The pathophysiological basis of chronic and acute pruritus is not fully understood. Besides histamine, a plethora of different neuromediators of itch, including neurotrophins, neuropeptides and their corresponding receptors, have been identified. In atopic dermatitis the release of these mediators leads to an activation of immune cells, such as mast cells and eosinophilic granulocytes, which in turn release neuromediators and cytokines that activate peripheral neurons. This review focuses on the neurophysiological interactions which regulate pruritus and summarizes the function of neurological and inflammatory mediators in atopic pruritus.

H1-antihistamine-refractory chronic spontaneous urticaria: it's worse than we thought - first results of the multicenter real-life AWARE study

BACKGROUND

Most data on chronic spontaneous urticaria (CSU) originate from highly selected patient populations treated at specialized centres. Little is known about CSU patient characteristics and the burden of CSU in routine clinical practice. AWARE (A World-wide Antihistamine-Refractory chronic urticaria patient Evaluation) is an ongoing global study designed to assess chronic urticaria in the real-life setting.

OBJECTIVE

To describe the baseline characteristics of the first 1539 German AWARE patients with H1-antihistamine-refractory CSU.

METHODS

This prospective non-interventional study included patients (18-75 years) with a diagnosis of H1-antihistamine-refractory CSU for > 2 months. Baseline demographic and disease characteristics, comorbidities, and pharmacological treatments were recorded. Quality of life (QoL) was assessed using the dermatology life quality index (DLQI), chronic urticaria QoL questionnaire (CU-Q₂ oL), and angioedema QoL questionnaire (AE-QoL, in cases of angioedema). Previous healthcare resource utilization and sick leave data were collected retrospectively.

RESULTS

Between March and December 2014, 1539 patients were assessed in 256 sites across Germany. The percentage of females, mean age, and mean body mass index were 70%, 46.3 years, and 27 kg/m² , respectively. The mean urticaria control test score was 7.9, one in two patients had angioedema, and the most frequent comorbidities were chronic inducible urticaria (CIndU; 24%), allergic rhinitis (18.2%), hypertension (18.1%), asthma (12%), and depression (9.5%). Overall, 57.6% of patients were receiving at least one pharmacological treatment including second-generation H1-antihistamines (46.3%), first-generation H1-antihistamines (9.1%), and corticosteroids (15.8%). The mean DLQI, total CU-Q₂ oL, and total AE-QoL scores were 8.3, 36.2, and 46.8, respectively. CSU patients reported frequent use of healthcare resources, including emergency services (29.7%), general practitioners (71.9%), and additional allergists or dermatologists (50.7%).

CONCLUSIONS AND CLINICAL RELEVANCE

This study reveals that German H1-antihistamine-refractory CSU patients have high rates of uncontrolled disease, angioedema, and comorbid CIndU, are undertreated, have impaired QoL, and rely heavily on healthcare resources.

Human basophils are a source of - and are differentially activated by - IL-31

BACKGROUND

Basophils are important effector cells involved in the pathogenesis of inflammatory skin diseases including chronic urticaria which is associated by increased IL-31 serum levels. So far the effects of IL-31 on human basophils are unknown.

OBJECTIVE

To analyse the functional role of IL-31 in basophil biology.

METHODS

IL-31 expression was evaluated in skin samples derived from chronic spontaneous urticaria patients. Oncostatin M receptor (OSMR), IL-31 receptor A (RA) and IL-31 protein expressions were analysed on human basophils from healthy donors. Basophil responses to IL-31 were assessed for chemotaxis, externalization of CD63 and CD203c as well as the release of histamine, IL-4 and IL-13.

RESULTS

IL-31RA and OSMR were expressed on human basophils. IL-31 was strongly expressed in the skin of patients with chronic spontaneous urticaria and was released from isolated basophils following either anti-IgE, IL-3 or fMLP stimulation. IL-31 induced chemotaxis and the release of IL-4 and IL-13 which was specifically inhibited by anti-IL-31RA and anti-OSMR. Conversely, IL-31 had no effect on CD63 and CD203c externalization or histamine release.

CONCLUSIONS AND CLINICAL RELEVANCE

Human basophils are a source of -and are activated by - IL-31 with the release of pro-inflammatory cytokines and the induction of chemotaxis indicating an important novel function of IL-31 in basophil biology.

Human basophil chemotaxis and activation are regulated via the histamine H4 receptor

BACKGROUND

IgE-mediated cross-linking of FcεRI results in the release of mediators stored in basophil granules, such as histamine and proteases, and in the de novo synthesis of sulfidoleukotrienes.

OBJECTIVE

In this study, we investigated the role of the histamine receptors, in particular that of the histamine H4 receptor (H4R), in modulating human basophil function.

METHODS

The mRNA expression of the histamine receptors was measured by real-time PCR. Migration of basophils was assessed using the modified Boyden chamber technique. The expression levels of CD63 and CD203c on the cell surface and the sulfidoleukotriene release were determined by flow cytometry and ELISA, respectively.

RESULTS

We could show that highly purified basophils express the H1R, H2R, and H4R but not the H3R mRNA. Human basophils expressed higher H4R mRNA levels as compared to the expression levels of the H1R (P < 0.01). Histamine and the H4R agonist ST-1006 initiated active migration of basophils (P < 0.001). A significant reduction in FcεRI cross-linking-mediated surface expression of CD63 and CD203c was observed on basophils after pre-incubation with histamine or the specific H4R agonist ST-1006 (P < 0.01). The synthesis and release of sulfidoleukotrienes from basophils after activation with different stimuli, by FcεRI cross-linking or by stimulation with hymenoptera venom allergens, were significantly reduced by histamine or the H4R agonist ST-1006 (P < 0.05-0.001).

CONCLUSION

These data imply that the H4R regulates IgE-dependent processes in human basophils and provides a novel function of the H4R preventing an overwhelming immune reaction by engagement of a negative feedback loop.

Childhood atopic dermatitis-Brain-derived neurotrophic factor correlates with serum eosinophil cationic protein and disease severity

Several studies have shown that neurotrophins including brain-derived neurotrophic factor (BDNF) play a role in chronic inflammatory skin diseases such as atopic dermatitis (AD). BDNF is increased in the serum samples of adults with AD. Interestingly, eosinophils of these patients can release and produce BDNF. We analyzed BDNF serum levels with ELISA and their correlation with SCORAD score, eosinophil cationic protein (ECP), total IgE, IL-4, IL-13 and IL-31 in children with AD (n = 56) compared to nonatopic healthy children (n = 25). In addition, we analyzed FLG loss-of-function mutations in 17 children with AD and their connection to BDNF. BDNF serum levels were significantly higher in children with AD. Further, BDNF correlated with disease activity, serum ECP, and total IgE serum levels in AD. There was no difference in BDNF levels of filaggrin-positive or filaggrin-negative children with AD, and there was no correlation of BDNF with IL-31 and Th2 cytokines including IL-4 and IL-13. Together, our data add new insights into the pathophysiology of AD, suggesting that serum BDNF which correlates with disease severity contributes to the regulation of inflammation in an eosinophil-, but not Th2-dependent manner.

Regulation of melanocortin 1 receptor in allergic rhinitis in vitro and in vivo

BACKGROUND

α-melanocyte-stimulating hormone (α-MSH) was shown to inhibit allergic airway inflammation and exert suppressive effects on human basophils.

OBJECTIVE

This study aims to extend our current knowledge on the melanocortin 1 receptor (MC1R) expression in nasal tissue of patients with allergic rhinitis (AR) and functional effects of α-MSH in human basophils especially from patients with allergic rhinitis.

METHODS

MC1R expression before and after nasal allergen provocation was studied in nasal mucosal tissue of AR patients and in a mouse model of allergic airway inflammation using immunofluorescence. In vitro regulation of the MC1R and CD203c surface expression on whole-blood basophils of patients with AR and controls was assessed with flow cytometry. Functional effects of α-MSH on isolated basophils were analysed regarding apoptosis with flow cytometry and chemotaxis using a Boyden chamber assay.

RESULTS

We detected an accumulation of MC1R-positive basophils in nasal mucosa tissue of patients with AR 24 h after nasal allergen provocation. Such accumulation was not present in mucosa sections from healthy controls. In mice with allergic airway inflammation, we found a clear accumulation of MC1R-positive basophils in the nasal tissue compared to control mice. MC1R expression was inducible in AR patients and controls by stimulation with anti-IgE. α-MSH inhibited anti-IgE and grass pollen induced upregulation of CD203c, but had no effect on chemotaxis or apoptosis of basophils in vitro.

CONCLUSIONS AND CLINICAL RELEVANCE

MC1R-positive basophils accumulate in the nasal mucosa of patients with AR after nasal allergen provocation. Since α-MSH suppresses proinflammatory effector functions in human basophils via the MC1R, it constitutes an interesting novel target for modulating the allergic inflammatory response.

Activation of KIT modulates the function of tumor necrosis factor-related apoptosis-inducing ligand receptor (TRAIL-R) in mast cells

BACKGROUND

Mastocytosis is characterized by the accumulation of mast cells (MCs) associated with activating mutations of KIT. Tumor necrosis factor-related apoptosis-inducing ligand receptors (TRAIL-Rs) are preferentially expressed on neoplastic cells and induce the extrinsic apoptotic pathway. Recent studies reported on the expression of TRAIL-Rs and TRAIL-induced apoptosis in cultured human MCs, which depend on stem cell factor (SCF)-induced or constitutive KIT activation.

MATERIAL AND METHODS

We sought to further define the impact of TRAIL-Rs on MCs in vivo and in vitro. Using Cre/loxP recombination, we generated mice with MC-specific and ubiquitous knockout of TRAIL-R. In these mice, anaphylaxis and numbers of MCs were investigated. We also explored the expression and function of TRAIL-Rs in cultured murine and human MCs upon activation of KIT. By conducting immunofluorescence staining, we analyzed the expression of TRAIL-Rs in MCs infiltrating the bone marrow of patients with mastocytosis.

RESULTS

MC-specific deletion of TRAIL-R was associated with a slight, but significant increase in anaphylaxis. Numbers of MCs in MC-specific knockouts of TRAIL-R were comparable to controls. Whereas cultured IL-3-dependent murine MCs from wild-type mice were resistant to TRAIL-induced apoptosis, SCF-stimulated MCs underwent apoptosis in response to TRAIL. Interestingly, activating KIT mutations also promoted sensitivity to TRAIL-mediated apoptosis in human MCs. In line with these findings, MCs infiltrating the bone marrow of patients with mastocytosis expressed TRAIL-R1.

CONCLUSIONS

Activation of KIT regulates the function of TRAIL-Rs in MCs. TRAIL-R1 may represent an attractive diagnostic and therapeutic target in diseases associated with KIT mutations, such as mastocytosis.

[Clinical symptoms and diagnostic workup of allergic reactions on the oral mucosa]

Contact allergies at the oral mucosa are associated with diverse symptoms. In this article we focus on the contact allergy of delayed type. Oral mucosa changes including stomatitis or lichenoid inflammation can give first evidence for such a contact allergy. Subjective symptoms including pain, burning or dryness of the oral mucosa can be associated with a contact allergy but may also occur in other diseases which need to be excluded. The first step in the diagnosis of a contact allergy is the complete examination of the oral mucosa. Additionally, a careful history of the patient's oral care products, drugs and dental materials is important. If mucosal changes are present, a patch test is recommended for the diagnostic work up for contact allergy of delayed type. In case of a positive patch test reaction, a careful check for the clinical relevance is needed in order to have a clear recommendation for both patient and dentist e.g. if replacement of prosthetic materials is needed.

EAACI taskforce position paper: evidence for autoimmune urticaria and proposal for defining diagnostic criteria

An autoimmune subset of chronic spontaneous urticaria is increasingly being recognized internationally, based on laboratory and clinical evidence that has accrued over the last 20 years. This evidence has been reviewed by a taskforce of the Dermatology section of the European Academy of Allergy and Clinical Immunology. Functional autoantibodies in chronic urticaria (CU) patient sera have been demonstrated against IgE and FcεRIα by basophil and mast cell histamine release assays and by basophil activation assays. Antibody specificity has been confirmed by immunoassay, but there is a poor correlation between functionality and immunoreactivity. Approximately 25% of CU patients have a positive basophil histamine release assay and show autoreactivity (a positive autologous serum skin test), whereas 50% are negative regarding both. Functionality of CU sera appears to be complement dependent on mast cells but not exclusively on basophils. Basophil activation by CU sera is predominantly restricted to IgG1 and IgG3 subclasses. Circumstantial evidence for CU being an autoimmune disease comes from an observed association with other autoimmune diseases, a strong association between serum functionality and HLA-DR4 haplotype and the good response of CU patients to immunotherapies. It was proposed that a study should be undertaken to prospectively validate potentially relevant clinical criteria (from the history, examination and routinely available clinical investigations) against a new 'gold standard' for the diagnosis of ACU (positive autoreactivity, functional bioassay and immunoassay) to define preliminary criteria sets for the diagnosis of ACU based on clinical and laboratory features with highest individual sensitivity and specificity.

[Assessment of pruritus - current standards and implications for clinical practice : consensus paper of the Action Group Pruritus Parameter of the International Working Group on Pruritus Research (AGP)]

With a prevalence of 20%, chronic pruritus is a symptom of many diseases with major impact on healthcare costs. The lack of specific therapeutic measures makes the development of new drugs and their testing in clinical trials urgent. It is not possible to measure pruritus in an objective way. For these reasons, it is necessary to have a series of standardized measures to characterize pruritus in a reliable way. Intensity scales such as the visual analog scale (VAS) are most frequently used to document the course of the symptoms. However, for assessing pruritus intensity, VAS is not an optimal instrument, although it cannot be dispensed with. The VAS should be combined with other scales in clinical studies in order to internally test the consistency of data. Other instruments for assessing intensity and course of pruritus are in the process of development. Presently scratch activity and scratch-associated lesions can be documented in a descriptive fashion. There are some studies that have employed devices to document scratch activity; however, methodological studies are not yet available. The patient-benefit index is an indispensable tool in clinical trials. A questionnaire for gathering data on the history and some pruritus-specific parameters has been developed and published. Questionnaires on patient quality of life, anxiety and depression are helpful in obtaining data on other cost-relevant parameters. A questionnaire on the quality of life, for instance, can provide important help in the assessment of the burden of the disease. The results of these questionnaires can be correlated with data on pruritus intensity scales. The relevant questionnaires have been partially digitalized so that they are available immediately as part of patient care. Additional methodological developments and studies are required in order to define a robust set of instruments for measuring pruritus in daily practice and in clinical studies.

[Antidepressant drugs : a reasonable therapy for 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.

Neuropeptide blood levels correlate with mast cell load in patients with mastocytosis

BACKGROUND

Mastocytosis is characterized by abnormal growth and accumulation of mast cells (MCs) in different organs. MCs have been shown to express receptors for neuropeptides. Furthermore, neuropeptides can activate MCs inducing cytokine production and MC mediator release, which further contribute to MC chemotaxis and stimulate the release of vasoactive peptides from sensory nerves. Thus, a contribution of neuropeptides to mastocytosis seems highly conceivable, but has not been investigated sufficiently yet. This study aimed to analyse blood levels of the neuropeptides substance P (SP), somatostatin (SST), vasoactive intestinal peptide (VIP), calcitonine gene--related peptide (CGRP) and expression of the SP receptor NK-1R in the skin of patients with mastocytosis (n = 46) compared to healthy controls (n = 69).

METHODS

Substance P, SST, VIP and CGRP plasma levels were analysed by ELISA, serum tryptase levels with the UniCAP System and NK-1R expression in the skin by immunohistochemistry.

RESULTS

Plasma levels of SP (P < 0.0001), SST, (P = 0.007), VIP (P < 0.0001) and CGRP (P = 0.003) were significantly increased in patients with mastocytosis compared to controls. Tryptase serum levels correlated significantly with neuropeptide levels, implying a link between MC load and neuropeptide blood levels in mastocytosis. NK-1R was expressed on the majority of MCs, and NK-1R-positive cells were increased in lesional mastocytosis skin compared to control skin (P = 0.01).

CONCLUSIONS

Elevated blood levels of the neuropeptides SP, SST, VIP and CGRP correlate with MC load and together with an increased expression of NK-1R in the skin of patients with mastocytosis indicate a role of neuropeptides in the pathophysiology of mastocytosis.

Dipeptidyl peptidase IV (DPP4) deficiency increases Th1-driven allergic contact dermatitis

BACKGROUND

CD26 or dipeptidyl peptidase IV (DPP4) is known to be involved in several immunological processes and has recently been reported to play a crucial role in the allergic responses of the lungs.

OBJECTIVES

To explore the impact of DPP4 on the allergic response of the skin.

METHODS

Skin biopsies from patients suffering from atopic dermatitis (AD) and healthy controls were investigated for the expression of CD26/DPP4. Furthermore, the functional impact of CD26 was investigated in two models of contact hypersensitivity using CD26/DPP4-deficient and wild-type rats. Dinitrochlorobenzene (DNCB) was used to induce a T helper type 1 (Th1)-dominated inflammation and toluene-2,3-diisocyanate for a Th2-pronounced inflammation. The inflammatory responses were determined by histological quantification, flow cytometry [fluorescence-activated cell sorting (FACS)], and an enzyme-linked immunosorbant assay (ELISA).

RESULTS

CD26/DPP4-expression was up-regulated in the lesional skin biopsies of patients compared with healthy controls as well as in both models of contact hypersensitivity. However, in the more Th2-driven model, a reduced inflammatory skin response was found in CD26/DPP4-deficient rats, analogous to the effects observed recently in a rat model of asthma. In partial contrast, there was an aggravation of local skin inflammation in CD26/DPP4-deficient rats under conditions of Th1-like skin inflammation.

CONCLUSION AND CLINICAL RELEVANCE

The up-regulation of CD26 in atopic dermatitis represents a new finding, which has also been seen in other inflammatory skin diseases. However, tissue expression of CD26/DPP4 in immunological skin response can either be beneficial or aggravating, depending on a possible Th1/Th2 shift. This might have consequences for humans suffering from diabetes mellitus treated by DPP4 inhibitors, who have eczematous skin diseases as a co-morbidity.

Influence of acupuncture on type I hypersensitivity itch and the wheal and flare response in adults with atopic eczema - a blinded, randomized, placebo-controlled, crossover trial

BACKGROUND

Itch is a major symptom of allergic skin disease. Acupuncture has been shown to exhibit a significant effect on histamine-induced itch in healthy volunteers. We investigated the effect of acupuncture on type I hypersensitivity itch and skin reaction in a double-blind, randomized, placebo-controlled, crossover trial.

METHODS

An allergen stimulus (house dust mite or grass pollen skin prick) was applied to 30 patients with atopic eczema before (direct effect) and after (preventive effect) two experimental approaches or control observation: acupuncture at points Quchi and Xuehai [verum acupuncture (VA), dominant side], 'placebo-point' acupuncture (PA, dominant side), no acupuncture (NA). Itch intensity was recorded on a visual analogue scale. After 10 min, wheal and flare size and skin perfusion (via LASER-Doppler) were measured at the stimulus site, and the validated Eppendorf Itch Questionnaire (EIQ) was answered.

RESULTS

Mean itch intensity was significantly lower in VA (35.7 +/- 6.4) compared to NA (45.9 +/- 7.8) and PA (40.4 +/- 5.8) regarding the direct effect; and significantly lower in VA (34.3 +/- 7.1) and PA (37.8 +/- 5.6) compared to NA (44.6 +/- 6.2) regarding the preventive effect. In the preventive approach, mean wheal and flare size were significantly smaller in VA (0.38 +/- 0.12 cm(2)/8.1 +/- 2.0 cm(2)) compared to PA (0.54 +/- 0.13 cm(2)/13.5 +/- 2.8 cm(2)) and NA (0.73 +/- 0.28 cm(2)/15.1 +/- 4.1 cm(2)), and mean perfusion in VA (72.4 +/- 10.7) compared to NA (84.1 +/- 10.7). Mean EIQ ratings were significantly lower in VA compared to NA and PA in the treatment approach; and significantly lower in VA and PA compared to NA in the preventive approach.

CONCLUSIONS

Acupuncture at the correct points showed a significant reduction in type I hypersensitivity itch in patients with atopic eczema. With time the preventive point-specific effect diminished with regard to subjective itch sensation, whereas it increased in suppressing skin-prick reactions.

Neurotrophins in healthy and diseased skin

Understanding the complex mechanism of allergic inflammatory skin diseases has been a main challenge of clinical and experimental research for years. It is well known that the inflammatory response is also controlled by tissue resident cells including neurons and structural cells. Thus, allergic inflammation triggers neuronal dysfunction and structural changes in diseased skin. Prime candidates for the interaction between immune, structural, and neuronal cells are presented by neurotrophins. Neurotrophins have initially been described for their neurotrophic capacity. However, recent evidence emerges that neurotrophins display bidirectional interaction pathways in activating structural cells, immune cells in addition to neurons. Neurotrophins including brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) are upregulated in allergic inflammatory skin diseases. Further, structural cells, neurons and tissue resident cells have not only been shown to be a target but also a source of neurotrophin. In this regard, eosinophil granulocytes which are key target effector cells in chronic inflammatory skin have been identified as a target of neurotrophins but are also capable of neurotrophin production. Thus, neuroimmune interaction mechanisms in allergic inflammatory skin display a novel pathophysiological aspect in which neurotrophins serve as prime candidates for bidirectional interaction mechanisms. In this review, we provide an actual overview of neurotrophins in healthy and diseased skin with special emphasis on atopic dermatitis and therapeutic implications.

Pathophysiology of itching and sneezing in allergic rhinitis

Itching and sneezing represent two of the main bothersome symptoms, apart from nasal obstruction and rhinorrhea in allergic rhinitis. Apparently, activation of the central and peripheral nervous system plays a major role in the pathophysiology of this process. Sensory nerves of the afferent trigeminal system including myelinated Adelta-fibres and thin, non-myelinated C-fibres of the nasal mucosa transmit signals generating sensations, including itching and motor reflexes, such as sneezing. These nerves can be stimulated by products of allergic reactions and by external physical and chemical irritants. Via axon reflex inflammatory neuropeptides including the tachykinins substance P (SP) and neurokinin A (NKA) and the calcitonin gene related peptide are released, leading to vasodilatation, increased vascular permeability (concept of "neurogenic inflammation"), glandular activation, leukocyte recruitment and differentiation of immune cells including mast cells, eosinophils, lymphocytes and macrophages. The present paper describes nasal (micro-) anatomy and innervation and explains the central and peripheral mechanisms initiating itching and sneezing in allergic rhinitis. Further, the role of neuropeptides and neurotrophins with regard to neuronal and immune cell activation which might play a key role in the future treatment of allergic rhinitis are discussed.

[New and rarley used treatment options for refractory hand eczema: local UVA-1 phototherapy, retinoids, calcineurin inhibitors]

Hand eczema (HE) is one of the most frequent skin diseases. HE has a wide spectrum, with variable etiology, severity, and morphology. It often displays a chronically relapsing course with a poor prognosis, and has a high impact on the quality of life. Although different treatment options exist, the management of patients with chronic HE is often unsatisfactory. We highlight new and rarely used approaches to treat chronic HE uncluding local UVA-1-phototherapy, retinoids including the new oral retinoid alitretinoin, and calcineurin inhibitors.

Differential up-regulation of neurotrophin receptors and functional activity of neurotrophins on peripheral blood eosinophils of patients with allergic rhinitis, atopic dermatitis and nonatopic subjects

BACKGROUND

Recent studies suggest that neurotrophins have a pivotal role in neuroimmune interactions. Indeed, in contrast to nonatopic subjects (NA), neurotrophins have been shown to be increased in atopic diseases such as allergic rhinitis (AR) and atopic dermatitis (AD).

AIM

The aim of the study was to assess the functional role of nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin (NT)-3 and -4 and the expression of pan-neurotrophin receptor (p75(NTR)) and tyrosine kinase (trk)A, -B and -C on peripheral blood eosinophils in AR, AD and NA.

METHODS

Peripheral blood eosinophils of patients with AR, AD and NA were purified by CD16 negative selection (purity>98%). Neurotrophin receptor expression was analysed by FACS analysis. Apoptosis test (FACS analysis) and chemotactic index (modified Boyden chamber assay) were assessed after stimulation with BDNF, NT-3/-4 and NGF.

RESULTS

The expression of trkA-C and p75(NTR) was significantly higher in AD>AR>NA (P<0.05-0.001). Apoptosis was significantly inhibited by BDNF, NGF, NT-3 in AD (P<0.05-0.001), by NT-3/-4 and NGF in AR (P<0.05-0.01) and by NT-3 (P<0.05-0.01) in NA eosinophils. Chemotaxis was significantly induced by BDNF and NT-3/4 (P<0.01-0.001) in AD peripheral blood eosinophils.

CONCLUSION

Neurotrophin receptor expression and neurotrophin functional activity was greatest in AD>AR>NA. AD eosinophils are pre-activated and may therefore better respond to neurotrophins. With this study, we provide new pathophysiologic insights into atopic diseases with a functional role of neurotrophins in peripheral blood eosinophils in AD and AR.

Modulation of neurotrophin and neurotrophin receptor expression in nasal mucosa after nasal allergen provocation in allergic rhinitis

BACKGROUND

Patients with allergic rhinitis (AR) feature both allergic airway inflammation and a hyperresponsiveness to nonspecific stimuli which is partly neuronally controlled. Still, it is unclear whether or not neurotrophins are involved in airway pathophysiology of AR and in nasobronchial interaction.

METHODS

Nine AR patients with mono-allergy to grass pollen and nine healthy controls underwent nasal allergen provocation (NP). Serum samples, nasal and bronchial biopsies were taken before (T(0)) and 24 h after (T(24)) NP. Pan-neurotrophin receptor p75(NTR), tyrosine kinase A (trkA), trkB, nerve growth factor (NGF), and brain-derived neurotrophic factor (BDNF) were assessed with immunohistochemistry, and NGF and BDNF levels with ELISA.

RESULTS

At T(24), BDNF and NGF were upregulated in nasal mucosa (P < 0.05) and increased in the peripheral blood of AR compared with T(0). The increase in nasal BDNF expression correlated positively with the maximum increase in total nasal symptom score in AR (P = 0.02). p75(NTR) was expressed on peripheral nerves and epithelial layer, trkA on endothelial cells, and trkB on mast cells. trkB + mast cells significantly decreased after NP in AR (P < 0.01). NP did not modulate p75(NTR) and trkA expression in nasal mucosa and had no effect on the expression of neurotrophins and receptors in bronchial mucosa.

CONCLUSION

This study shows that neurotrophins and their receptors are expressed in human airways. Allergic rhinitis was characterized by a modulation of BDNF, NGF, and trkB in nasal mucosa after NP and a correlation of nasal BDNF with the maximal increase of total nasal symptom score. Therefore, our data suggest that neurotrophins participate in upper-airway pathophysiology in AR, whereas their role in nasobronchial interaction remains unclear.

Moderne Diagnostik und Therapie der Urtikaria

The different urticaria subtypes represent a common diagnostic and treatment challenge for the dermatologist. Usually, acute urticaria is treated symptomatically with modern H1 antihistamines and, if needed, short courses of glucocorticosteroids. In acute urticaria which is often induced by an acute infection no further diagnostic procedures are recommended. In contrast, a targeted work-up followed by specific therapy is required for chronic urticaria, physical urticaria and special urticaria types, because many of these subtypes are characterized by their persistence for several years and have a profound impact on the quality of life. This article elucidates the management of urticaria by presenting five characteristic case reports of patients managed in a special urticaria consulting hour.