Bibliothek

Notizen: Summary Atopic eczema (AE) is a common skin disorder. Eczematous lesions showing macroscopic, microscopic and immunopathological resemblance to lesional AE can be induced by aeroallergens by epicutaneous testing (atopy patch test, APT). Altered epidermal barrier function, as determined by transepidermal water loss (TEWL), is a typical feature of patients with AE. The present investigation was performed to define the differences in the epidermal barrier function between positive APT reactions to aeroallergens and positive patch test reactions to contact allergens in AE patients. Allergen extracts from grass pollen, birch pollen, cat dander and house dust mite (Dermatophagoides pteronyssinus) were applied in large Finn chambers on Scanpor for 48h on the clinically unaffected and untreated skin of the back, in 11 patients with AE. The same procedure was done with 27 contact allergens of a standard test battery. Test reactions were read and TEWL was measured after 48 and 72h. Eight of the 11 patients developed positive APT reactions toD. pteronyssinus, two to cat dander and one to birch pollen. Seven of the 11 patients showed positive patch test reactions to nickel sulphate, two to potassium dichromate, one to thiuram-mix and one to paraphenylenediamine. Vehicle controls were negative. The TEWL of the positive APT reactions was significantly higher, both after 48 h (mean ± standard deviation 10·0±6·5 g/m2h) and after 72 h (9·7±5·4g/m2h) as compared with the control site (48/72h: 4·4±1.5/4·1±1·4 g/m2h) (P〈0·01). In contrast, TEWL of the positive patch test reactions to contact allergens (48/72h; 5·4±2·2/5·4±1·9g/m2h) was similar to that of the control site (48/72 h: 5·2±2·1/5·0± 1·8g/m2h) (not significant). The relative TEWL at 48 h and 72 h, expressed as the ratio between the positive patch test and the control site, was significantly higher in the positive APT reactions (48/72 h: 218·8±80·4%/232·0±85·9%) compared with positive patch test reactions to contact allergens (48/72 h: 102·1±12·0%/107·1±9·5%) (P〈0·01). It is concluded that the epidermal barrier function in AE patients is altered only in positive APT reactions, in contrast to positive patch test reactions to contact allergens. As a consequence of this aeroallergen-induced altered epidermal barrier function, further allergens can more easily penetrate the skin, inducing a vicious circle and perpetuating the eczematous lesions.

Notizen: A 51-year-old white male suffering from metastatic malignant melanoma of the skin presented with lymph node metastases and paraneoplastic retinopathy 4 years after resection of the primary tumour. There were no cerebral metastases. Ocular symptoms consisting of night blindness and sensations of ‘shimmering lights’ persisted after total resection of the inguinal lymph node metastases and administration of dacarbazine and prednisone. Perimetry of both eyes was abnormal with concentric restriction. Electroretinography showed significantly reduced amplitudes in both eyes. Only 11 patients with melanoma-associated retinopathy (MAR) have been described. High titres of autoantibodies against whole retina extract were detected by enzyme-linked immunosorbent assay (ELISA) reactions. Indirect immunohistochemistry showed strong autoantibody activity against retinal bipolar cells.

Notizen: Glycoprotein Ilb-IIIa (integrin alpha lib beta3) is an adhesive receptor involved in platelet aggregation and adhesion to the extracellular matrix. Previous.studies showed the presence of IIb-IIIa-like glycoproteins on cells of melanoma cell lines and on cells of lymph node metastases. This study evaluates the presence of glycoprotein IIb-IIIa subunits on cells of primary cutaneous malignant melanomas wilh (n= 4) and without (n= 9) metastases over a period of 6 years and on naevus cells (n= 4). Monoclonal antibodies directed against the subunits of the glycoprotein IIb-IIIa receptor were used on paraffin-embedded sections and evaluated by means of immuno-histochemistry. The giycoprotein lib subunit was exclusively present on cells of metastatic melanomas. It was not found on non-metastatic melanomas or benign melanocytes. These data favour the role of the integrin receptor glycoprotein IIb-IIIa in the metastatic behaviour of malignant melanomas.

Notizen: Summary In a subgroup of patients with atopic eczema (AE), eczematous skin lesions can he induced by epicutaneous testing with aeroallergens (the atopy patch test: APT). An increased frequency of positive APT has been found in AK patients showing a predictive lesional pattern affecting air-exposed skin areas. This study investigates the dose-response ofthe APT in two dilTerent patient groups with AE. Petrolatum preparations of house dust mite, cat dander and grass pollen allergens in four concentrations (500–10,000) protein nitrogen imits) were tested epicutaneously in 57 patients with AE. who were prospectively divided in two groups according to whether their AE pattern was with (group I) or without (group II) a predictive distribution. Sixty-nine per cent of patients in group I. and 39% in group II. had positive APT reactions (P = 0.02). The reactions in group I were elicitable with lower allergen concentrations (P = 0.03). A clinically recognizable subgroup of patients with AE showed increased cutaneous sensitivity to aeroallergens.

Notizen: Summary The clinical and histopathological classification of erythema exudativum multiforme major (EEMM), Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are difficult, due to the lack of clear-cut criteria. Based on a new clinical classification, 149 of 219 (68%) histopathological specimens, from a total of 534 patients with EEMM. SJS and TEN, have been reviewed. A comparison was made with the clinical picture, and any past history of infection or drug intake. All patients had been included in the German Registry of Severe Skin Reactions between April 1990 and December 1993. No differences could be found between the biopsies examined and the total number of histopathological specimens, concerning clinical diagnosis, gender and age. Sections from 28 of 149 specimens were not diagnostic or were too old to be properly evaluated. In nine cases, other diagnoses were proposed. One hundred and eleven of the histological slides with the diagnosis of EEMM (n= 16), SJS (n=34) and TEN (n=61), were classified as epidermal type of erythema multiforme. In these 111 slides, necrotic keratinocytes could be found, ranging from individual cells to confluent epidermal necrosis. The epidermo-dermal junction showed changes ranging from vacuolar alteration up to subepidermal blisters. The dermal infiltrate was superficial and mostly perivascular. It was sparse in SJS and TEN, and more pronounced in EEMM. Oedema in the papillary dermis was evident occasionally in all clinical groups. In 59 of 111 cases (53%), at least one eosinophil was present in the dermis. In 11 of 111 (10%), more than 10 eosinophils per field could be seen. Eosinophils were less common in the patients with the most severe forms of TEN, in whom there was detachment of more than 30% of the skin surface area. No differences in the history for drug intake, or for infection with Mycoplasma pneumoniae, herpes simplex and other organisms, could be detected between patients with or without eosinophils in their skin sections. This dermatopathological study of patients with EEMM. SJS and TEN indicates that the epidermal type of erythema multiforme is the pathological correlate for these diseases.

Notizen: Schäfer T, Ring J. Epidemiology of allergic diseases.The escalation of allergic diseases (hay fever, asthma, atopic eczema) over recent decades has been linked to an increase in environmental pollutants. The prevalence of hay fever is associated with genetic predisposition, and some reports show an association with urban areas, socioeconomic status, and combined high allergen and automobile exhaust exposure. In asthma, there is also some evidence for geographical variations in prevalence; exercise challenge tests prove positive more often in urban areas than in rural areas. Although genetic predisposition is the strongest single risk factor for atopic eczema, air pollutants may aggravate the condition by acting as unspecific irritants and immunomodulators, leading to increased immunoglobulin E expression. In a study of 678 pre-school children, the influence of maternal smoking habits on individual measures of atopy revealed a positive association between smoking during pregnancynactation, and a positive history of atopic eczema. An East-West German comparative study examining different types and levels of air pollution, i.e. sulphurous (industrial; East) and oxidising (urban; West), showed that the prevalence of atopic eczema was greatest in East Germany. When various direct and indirect parameters of air pollution exposure were measured, the greatest association with atopic eczema was found with NOx exposure (indoor use of gas without a cooker hood), and close proximity to roads with heavy traffic. The increased prevalence of atopic eczema cannot be explained by changes in study methodology over time, or conventional risk factors alone; environmental risk factors may be an important contributing factor.

Notizen: Urticaria is one of the most common and, in its chronic course, excruciating dermato-allergic diseases. Apart from the dermatological diagnosis, the identification and evaluation of causal triggering factors is of utmost importance. Here a ‘three-step guideline’ (according to Ring and Przybilla) has gained acceptance, ranging from a general basic examination via an intensive investigation until oral provo-cation tests for food allergy and oral provocation tests for idiosyncrasy (OPTI) against food additives. Apart from true IgE-mediated allergies, pseudo-allergic reactions against food additives as well as food contents represent a major problem in chronic urticaria. Recently gastric mucosal colonization with Helicobacter pylori as the trigger of chronic urticaria has received attention. New patho-physiological concepts describe autoantibodies that are directed either against IgE or against the high-affinity IgE-receptor on the surface of mast cells and basophil leucocytes. In the intradermal test with autologous serum positive wheal and flare reactions can be observed (Greaves’ test). In many patients with chronic urticaria considerable psychosomatic involvement is also observed. Histamine is one of the major mediators of most forms of urticaria although in some cases, especially physical urticaria, other mediators seem to play a role. Therefore antihistamines, and mainly H1 antihistamines, are the mainstay of antiurticaria therapy. Some studies have shown a benefit of combined H1- and H2-antagonist treatment in special forms of urticaria namely urticaria factitia. Similarily pretreatment with combined H1 and H2 antagonists has been proven to reduce effectively the frequency of pseudo-allergic reaction to some histamine-releasing drugs used in radiology or surgery. More than 50 years after the first introduction of an antihistamine into allergy therapy, antihistamines still represent modern and exciting agents contributing to the continuous improvement of antiallergic therapy. Antihistamine therapy can be performed with either the classical or second generation antihistamines. Classical antihistamines are connected with considerable side-effects especially sedation and anticholinergic effects. New non-sedating antihistamines have been developed that do not cross the blood–brain barrier. The efficacy of mizolastine, a new non-sedating H1 antagonist, has been evaluated in several placebo-controlled and comparative clinical trials. Overall, mizolastine 10 mg/day was found to be significantly more effective than placebo and as effective as other second generation antihistamine drugs in the management of patients with chronic urticaria, with a rapid and sustained action.

Notizen: Reduction in the size of the allergen-induced late-phase reaction (LPR) is seen as a consequence of successful allergen specific immunotherapy.〈section xml:id="abs1-2"〉〈title type="main"〉ObjectiveIt was the aim of this study to characterize the cellular infiltrate at the sites of cutaneous LPR that may occur following injection of a depot pollen allergoid (Allergovit®) during immunotherapy and thereby determine the immunological nature of the response.〈section xml:id="abs1-3"〉〈title type="main"〉MethodsPunch biopsies were taken 24 h after subcutaneous injection of a depot pollen allergoid from eight patients that showed LPR and a further five patients that did not. Additional biopsies taken 24 h after injection of allergoid-free depot in the same patients served as controls. Immunoenzymatic labelling of the cryostat sections with different antibodies was performed with the APAAP technique. Results were expressed as cells/field (400 × magnification).〈section xml:id="abs1-4"〉〈title type="main"〉ResultsSimilar dermal cellular infiltrations were seen following depot allergoid injections in patients both with and without LPR. Patients with LPR showed statistically significant increases in total cells, CD4+ cells, CD11c+ cells, CD45RO+ cells, CD45RB+ cells and activated eosinophils at the reactions sites as compared with control sites. In patients without LPR CD11c+ cells, HLA-DR+ cells and CD45RA+ T cells increased significantly. CD8+, CD1a+, NP57+, CD23+ and CD25+ cells did not differ significantly in either group.〈section xml:id="abs1-5"〉〈title type="main"〉ConclusionThese results indicate that activation of T cells, monocytes/macrophages and eosinophils at the sites of LPR following injection of depot allergoid are comparable with those following injection of allergen. Even in the absence of a cutaneous LPR, subsets of T cells and monocytes/macrophages increased. These cell activations may reflect events associated with the mechanisms of allergoid-based specific immunotherapy, and suggest that at least part of the late-phase reaction may be independent of IgE.