The effect of grenz rays on irritant skin reactions in man

To investigate the effect of grenz rays on irritant contact reactions, eleven healthy volunteers were studied. They were given 3 Gy of grenz rays, once a week for 3 weeks, to a defined area of the back. Twenty-four hours after the last treatment, serial dilution sodium lauryl sulphate patch tests were applied both on the grenz ray treated area and on the untreated control skin. Biopsy specimens were taken from the irritant reactions both from the grenz ray treated area and from the control area and different cell populations in dermis and epidermis were identified by monoclonal antibodies (Leu 2, 3, 4, 7, Leu M1, B1, OKT6). In the grenz ray treated epidermis there was a pronounced reduction of OKT6-positive cells but the composition of the dermal cellular infiltrate did not differ between control and grenz ray treated skin. The assessment of the patch test reactions did reveal a tendency towards weaker reactions in the grenz ray pre-treated skin but this difference was not statistically significant. It is concluded that grenz rays do not have a marked effect on the elicitation of irritant reactions.     

Lymphocytes and Langerhans cells in patch tests

The distribution of immunocompetent cells was analysed in allergic (nickel) and irritant (dithranol) patch tests using conventional transmission electron microscopy and labelling with monoclonal antibodies in an avidin-biotin immunoperoxidase study. The biopsies were taken 24 or 48 h after the allergen/irritant application. In allergic and irritant reactions, most inflammatory cells were OKT11 positive (pan T lymphocytes). The majority of these cells were also OKT4 positive (helper/inducer T lymphocytes), while the minority were OKT8 positive (suppressor/cytotoxic T lymphocytes). NK9 positive cells (natural killer cells) were observed in small numbers. The number of dendritic OKT6 and OKIal positive cells (Langerhans cells) in the epidermis was unaffected in allergic reactions. In irritant reactions, a normal number of OKT6 positive Langerhans cells was observed, while the number of OKIal positive cells had increased in the epidermis. Dithranol caused prominent fine structural changes in the mitochondria of the Langerhans cells, while the keratinocytes appeared largely unaffected. The present study indicates that allergic and irritant patch tests cannot be differentiated reliably using current immunohistopathological or electron microscopic techniques, in spite of the small differences observed.     

Expression of OKT6 antigen by Langerhans cells in patch test reactions

Previous studies in humans and guinea pigs indicate that Langerhans cells (LC) participate in elicitation of allergic contact dermatitis. The number and morphology of LC was determined in acute and healed allergic patch test sites, control (petrolatum) sites and normal skin in nickel-sensitive individuals using OKT6 monoclonal antibody and avidin-biotin/peroxidase labeling. Compared to normal skin, the staining intensity and number of epidermal LC was significantly increased in allergic (p less than 0.02) and petrolatum control (p less than 0.02) sites, and in 6- to 8-week old allergic patch test sites (p less than 0.006). The in situ changes in LC induced by petrolatum alone may be a result of the occlusive patch test, or may suggest that petrolatum is not as neutral as previously believed. The nickel-induced increase in LC may indicate changes in the LC present in the epithelium at the time of testing, or migration of additional LC into the epithelium, which can then remain in situ for weeks after the antigenic challenge. The specificity of the LC increase in allergic contact dermatitis is questioned on the basis of the increase noted with petrolatum.     

Active participation of eosinophils in patch test reactions to inhalant allergens in patients with atopic dermatitis

Intracutaneous testing and patch tests with house dust mite and grass pollen allergens were performed in patients with atopic dermatitis. Only patients with an immediate type skin reaction to house dust mite or grass pollen allergens showed a positive patch test reaction to these allergens 24-48 h after testing. Occasionally positive patch test reactions at 20 min, 2 h and 6 h were also observed. Patch test reactions were not found in normal controls or atopic patients without atopic dermatitis. Analysis of the cellular infiltrate demonstrated an influx of eosinophils into the dermis, starting from 2-6 h after patch testing. Immunostaining with antibodies against granular constituents of the eosinophils revealed that the infiltrating eosinophils were in an activated state and had lost part of their granular contents. At 24 h eosinophils also appeared in the epidermis. Electron microscopy showed that in the epidermis, some eosinophils were in close contact with Langerhans cells, suggesting a cell-cell interaction. Taken together, these results strongly suggest an active role for eosinophils in patch test reactions to inhalant allergens in atopic dermatitis patients.     

The presence of IgE molecules on epidermal langerhans cells in patients with atopic dermatitis

Summary Skin sections of clinically involved and clinically normal-looking skin from patients with atopic dermatitis were incubated with anti-human IgE antibodies using the indirect immunoperoxidase technique. Apart from positive dermal anti-IgE staining, positive epidermal anti-IgE staining was also observed. The morphology of the epidermal staining cells suggested the involvement of dendritic cells. This was confirmed by positive immuno-double labelling with OKT6 and anti-IgE. This phenomenon seemed to be specific for atopic dermatitis since skin sections from normal nonatopic controls, patients with allergic asthma, contact dermatitis, and schistosomiasis showed no epidermal anti-IgE staining. To further elucidate the nature of the epidermal anti-IgE staining cells, epidermal cell suspensions were prepared from clinically involved skin from patients with atopic dermatitis. These cell suspensions also showed positive anti-IgE staining cells and positive immuno-double labelling with OKT6 and anti-IgE. Immunogold electron microscopy with anti-IgE on epidermal cell suspensions from patients with atopic dermatitis showed gold particles on the cell membranes of cells containing Birbeck granules, being Langerhans' cells. Epidermal cell suspensions from normal non-atopic controls were negative. The presence of IgE molecules on epidermal Langerhans' cells, which seems to be specific for patients with atopic dermatitis, provides an explanation for the high frequency of positive patch test reactions to inhalant allergens.     

Immunopathological and ultrastructural findings in human allergic and irritant contact dermatitis

The histopathological features of allergic contact dermatitis were compared with those of irritant contact dermatitis in a group of 17 subjects. Each patient received simultaneous patch tests of a known allergen and a standardized irritant (benzalkonium chloride). The cellular changes occurring between 3 h and 7 days after patch test application were studied by light and electron microscopy and immunocytochemistry. No differences were observed between the induced allergic contact dermatitis (ACD) and the irritant contact dermatitis (ICD), either in the responding cell types or the sequence of cellular events. Both reactions showed a predominantly T lymphocyte infiltrate with no polymorphonuclear leukocyte involvement. Apposition of Langerhans cells to lymphocytes in the epidermis was seen in both types of response. Considerable variability in the intensity of reaction to irritant and allergen occurred within individuals. There was no statistically significant difference between the intensity of the reactions to the irritant and the allergen.     

The CXCR3 activating chemokines IP-10, Mig, and IP-9 are expressed in allergic but not in irritant patch test reactions.

Differentiation between allergic and irritant contact dermatitis reactions is difficult, as both inflammatory diseases are clinically, histologically, and immunohistologically very similar. Previous studies in mice revealed that the chemokine IP-10 is exclusively expressed in allergic contact dermatitis reactions. In the present study, we investigated whether the mRNA expression of IP-10 and the related CXCR3 activating chemokines, Mig and IP-9 are also differentially expressed in human allergic contact dermatitis and irritant contact dermatitis reactions. Skin biopsies from allergic (13 cases) and sodium lauryl sulfate-induced irritant patch test reactions (13 cases), obtained 1-72 h after patch testing, were studied by means of an in situ hybridization technique. Results of chemokine mRNA expression were correlated with clinical scoring, histology, and immunohistochemical data including the proportion of inflammatory cells expressing CXCR3, the receptor for IP-10, Mig, and IP-9, and ICAM-1 and HLA-DR expression on keratinocytes. IP-10, Mig, and IP-9 mRNA were detected in seven of nine allergic contact dermatitis reactions after 24-72 h, but not in sodium lauryl sulfate-induced irritant contact dermatitis reactions. ICAM-1 expression by keratinocytes was only found in allergic contact dermatitis reactions and correlated with chemokine expression. Moreover, up to 50% of the infiltrating cells in allergic contact dermatitis expressed CXCR3, in contrast to only 20% in irritant contact dermatitis reactions. In conclusion, we have demonstrated differences in chemokine expression between allergic contact dermatitis and irritant contact dermatitis reactions, which might reflect different regulatory mechanisms operating in these diseases and may be an important clue for differentiation between allergic contact dermatitis and irritant contact dermatitis reactions.     

Comparative histology and immunohistochemistry of tests of immediate allergic reaction and type I contact dermatitis

Contrary to type IV contact dermatitis, histochemical studies of immunological mechanisms in type I contact dermatitis are rare. To analyse the immunohistochemical kinetics of immediate type I reactions we followed up prick-test reactions to individual specific allergens in 5 atopics with respiratory allergy (group I) and in 4 patients with proven type I contact dermatitis (group II). Punch biopsies (diameter 6 mm) were taken 20 minutes, 6, 24 and 72 h after prick testing. Histological investigations were performed on paraffin-embedded tissue; immunohistochemical studies were done one frozen tissue with a panel of monoclonal antibodies applying the alkaline-phosphatase-anti-alkaline-phosphatase-complex method. In type I contact dermatitis a moderate lympho-monocytic dermal infiltrate appeared, which increased until 72 hrs after testing. In contrast, the immediate allergic reactions of group I revealed only mild lympho-monocytic infiltration in all proven sequential biopsies. No quantitative differences concerning the immunohistochemical pattern of OKM-1, OKM-5, Leu-2a and Leu-3a were observed between the two groups. Group II showed an increase in HLA DR, OKT6, anti-IgE- and anti-IL-2-receptor immunoreactivity whereas group I exhibited only moderate or no immunoreactivity. A dendritic anti-IgE-staining pattern, most probably on Langerhans cells, was only observed in the epidermis of group II patients. A pathogenetic concept of IgE-mediated type I contact dermatitis is presented and possible relationships with atopic dermatitis are discussed.     

Different in situ distribution patterns of dendritic cells having Langerhans (T6+) and interdigitating (RFD1+) cell immunophenotype in psoriasis, atopic dermatitis, and other inflammatory dermatoses

Dendritic cells bearing Langerhans cell (OKT6+) or interdigitating cell (RFD1+) immunophenotype may be regularly detected within the dermis of chronic skin diseases characterized by a lymphohistiocytic (lymphoreticular) infiltrate. These 2 subsets of antigen-presenting cells within the dermis of lesions of exacerbating chronic plaque psoriasis, exacerbating nummular dermatitis (discoid eczema), atopic dermatitis, allergic contact dermatitis, pityriasis rosea, lichen ruber planus, and cutaneous lupus erythematosus were quantified using computer-assisted morphometry. The mean dendrite length per dermal dendritic cell was significantly higher for RFD1 than for OKT6 (74.4 +/- 0.98 microns vs 70.0 +/- 1.26 microns: p = 0.0023). The mean dendrite length per dermal dendritic cell was remarkably constant for each marker in the various diagnostic categories studied. Disease-specific patterns of total dendrite length and number (expressed per 100 infiltrating mononuclear cells) of these 2 dendritic cell types within the subepidermal infiltrates were obtained. Pityriasis rosea was characterized by its unique high percentage of OKT6+ Langerhans cells. Atopic dermatitis and psoriasis had relatively high percentages of both RFD1+ interdigitating cells and OKT6+ Langerhans cells. Nummular dermatitis had an intermediate number and total dendrite length for OKT6, but was relatively low in RFD1+ cells. Allergic contact dermatitis, lichen planus, and lupus erythematosus had low numbers and dendrite lengths for both dendritic cell subsets. It is suggested that pityriasis rosea is characterized by an abnormal migration pattern of Langerhans cells. Psoriasis and atopic dermatitis may be examples of diseases in which skin-localized antigen-presenting and T-cell-inducing events are continuously taking place. The other diseases may reflect inflammatory processes in which local antigen presentation is less relevant to the tissue reaction.     

Occupational allergic contact dermatitis from spices

About 1000 patients were investigated at our clinic during 1991 for occupational skin disease. and 5 had occupational allergic contact dermatitis from spices. The patients were chefs, or kitchen, coffee room, and restaurant workers. All patients had hand (or finger) dermatitis. The causative spices were: garlic, cinnamon, ginger, allspice and clove, The same patients also had allergic patch test reactions to foods: tomato, lettuce and carrot. Paprika elicited a weak allergic patch test reaction in 2 patients. Occupational allergic contact dermatitis from spices is relatively rare, but needs to be taken into consideration in patients who have hand dermatitis, and work with spices and foods, Patch testing with spices as is useful, but testing with dilutions in pet, may be needed to confirm that the patch test reactions are allergic. Patients also need to be prick tested with spices and foods.     

Antigen-presenting cells and keratinocytes express interleukin-12 in allergic contact dermatitis

Interleukin‐12 (IL‐12) has previously been suggested as playing a major rôle in the activation of cytotoxic lymphocytes. Recent reports indicate that cytotoxic CD8+ cells are critically involved in the elicitation phase of contact hypersensitivity reactions. In this study, the in situ expression of IL‐12 was investigated in normal human skin and in allergic contact dermatitis by immunohistochemistry. Skin biopsy specimens were obtained from allergic patch test reactions after 3 days, and from normal skin in 8 subjects. In contrast to normal skin, a strong enhancement of IL‐12 immunoreactivity was observed in the mononuclear cell infiltrate of allergic contact dermatitis. IL‐12 immunoreactivity was mainly located in the cytoplasm of dermal dendritic cells and macrophages as well as of some Langerhans cells. IL‐12‐positive cells were often found in close apposition to lymphocytes. Furthermore, positive immunostaining was also detected in keratinocytes at sites of marked exocytosis and spongiosis in the epidermis. In conclusion, the enhanced in situ expression of IL‐12 may contribute to the activation of cytotoxic lymphocytes and thereby represent an important factor in the pathogenesis of contact hypersensitivity reactions in humans.     

Allergic contact dermatitis due to phenylephrine hydrochloride, with an unusual patch test reaction

2-day (2-D) closed patch tests are often used in daily clinical practice and useful for evaluating the cause of allergic contact dermatitis. However, even when 2-D closed patch tests at appropriate concentrations are performed for suspected allergic contact dermatitis based on clinical findings, positive reactions are not always obtained. Therefore, although the use of the allergen again induces similar symptoms, a definite diagnosis cannot be made in some cases. We report a case of allergic contact dermatitis due to phenylephrine hydrochloride in eyedrops, with an unusual patch test reaction. Although the results of the routine 2-D closed patch test were negative, a definite diagnosis could be made by closed scratch-patch test. In addition, long-lasting allergic patch test reactions were observed at the positive scratch-patch test site for about 3 months. We speculated that these unusual results on patch testing in our case were associated with the degree of percutaneous absorption of causative agents. Therefore, even when 2-D closed patch tests are negative, scratch-patch tests may be indicated for patients in whom clinical symptoms continue strongly to suggest contact dermatitis.     

Oral cyclosporin inhibits the expression of contact hypersensitivity in man

The expression of delayed contact hypersensitivity was studied in 6 patients with chronic contact dermatitis treated with cyclosporin A (CsA) 5 mg/Kg/day. Quantitative patch test challenge was used to establish individual dose-response curves and threshold concentration to certain allergens in the European Standard Battery. In all 6 patients, responses were reduced over the whole range of allergen concentrations, and in the 5 in whom the threshold for expression of contact hypersensitivity could be determined, the threshold was raised by CsA therapy. In addition, the clinical manifestations of allergic contact dermatitis underwent complete resolution within 2-3 weeks of CsA therapy. It was concluded that CsA inhibits expression of delayed contact hypersensitivity reactions in human skin.     

Patch testing with methyldibromo glutaronitrile, a multicentre study within the EECDRG

Contact allergy to and allergic contact dermatitis from methyldibromo glutaronitrile (MDBGN) have frequently been reported. As there has been no agreement on which MDBGN test preparation to use, a study was initiated to help determine the optimal patch test preparation for MDBGN. 2661 consecutively patch tested patients at 11 test clinics representing 9 European countries participated. Petrolatum preparations with MDBGN at 1.0%, 0.5%, 0.3% and 0.1% were inserted in the standard series. Contact allergy rates were noted in the range 4.4-1.1% following decreasing test concentrations. Reactions not fulfilling all criteria to be classified as allergic reactions could represent either weak allergic or irritant reactions, and such reactions were noted in the range 8.2-0.5% with decreasing concentrations. A significant number of these reactions represented weak allergic reactions, as allergic reactions were obtained to higher patch test concentrations in the same individual. Morphologically irritant reactions were noted only for the highest test concentrations. In summary, the contact allergy rates and frequencies of doubtful and irritant reactions vary with the patch test concentration. The final decision on patch test concentration for MDBGN should not only rely on these factors but also include information on patch test concentrations required to diagnose individual cases with allergic contact dermatitis from MDBGN as well as results of repeated open application tests.     

Retrospective survey of patch testing at department of dermatology and venerology, zagreb university hospital center in zagreb, croatia

Epicutaneous (patch) test is a standard test to confirm contact allergy. During a six-year period (1998-2003), contact allergic dermatitis was diagnosed in 4132 (65%) of 6341 patients using standard patch test with a Croatian series of allergens according to the International Contact Dermatitis Research Group (ICDRG). The most common clinical diagnoses related to contact allergy (male; female) were contact allergic dermatitis (65.4%; 72.2%); atopic dermatitis (15.9%; 11.7%); contact irritant dermatitis (7.0%; 6.6%) and nummular eczematoid dermatitis (4.2%; 2.4%). According to occupation, positive patch test reaction was most commonly observed in workers, whereas 65% of patients showed positive reactions to one or more substances. There was an increased frequency of positive patch test reactions to potassium dichromate, nickel sulfate, thimerosal and neomycine sulfate, along with a significant decrease in the frequency of positive patch test reactions to cobalt chloride, carba mix, wood tars, detergents, parabens mixture, urushiol and rubber mixture. We strongly recommend keeping up-to-date with the epidemiology of contact allergy in Croatia.     

Swimming pool contact dermatitis caused by 1-bromo-3-chloro-5,5-dimethyl hydantoin

Background. Bromo‐3‐chloro‐5,5‐dimethylhydantoin (BCDMH) is a chemical used as a disinfectant for recreational water. BCDMH was described as being responsible for an epidemic of irritant contact dermatitis in the UK (1983), and its sensitizing capacity was also discussed. Objectives. The aim of this study was to assess whether BCDMH used to disinfect swimming pools and spas can cause allergic contact dermatitis among its users. Methods. Ten patients suffering from dermatitis associated with using swimming pools disinfected with BCDMH and 40 controls were studied. Several dilutions of BCDMH, 10% to 1 ppm, were patch tested. Results. All 10 patients studied showed a positive patch test reaction to BCDMH 1% in petrolatum. At least one case showed occupational relevance, with a positive reaction even at 1 ppm. Conclusion. On the basis of the clinical findings, the positive patch test reactions to BCDMH, and the negative patch test reactions in controls, the suggested diagnosis was allergic contact dermatitis caused by BCDMH used as a disinfectant in the swimming pool water. Contact allergy should be taken into consideration when patients suffer from swimming pool‐associated itchy dermatitis.     

Contact dermatitis sparing the eruption of herpes zoster and its periphery

A 63-year-old male developed allergic contact dermatitis with antibiotic ointment applied to the skin eruptions of herpes zoster. From the result of patch test, fradiomycin sulfate contained in the ointment was identified as the contact sensitizing antigen. Strangely, this contact dermatitis was confined to the area surrounding the sores, sparing the lesions and their periphery. We postulated that a decrease in Langerhans cell activity in the herpes zoster lesions and their peripheral area was primarily responsible for this phenomenon, since an important role of Langerhans cells in host defence against herpes virus infection has recently been demonstrated.     

Distribution of natural killer cells and lymphocyte subclasses in Jessner's lymphocytic infiltration of the skin and in cutaneous lesions of discoid and systemic lupus erythematosus

We studied the cell infiltrates in biopsies from lymphocytic infiltration of the skin (LIS), with six monoclonal T cell antigen-specific antibodies and compared the reactivity pattern with those in biopsies from discoid and systemic lupus erythematosus skin lesions and allergic contact skin reactions. A newly described antibody (NK₉) recognizing natural killer (NK) cells and activated cytotoxic T lymphocytes was included, and the numbers and activity of circulating NK cells was determined. Immunohistochemical staining revealed that the numbers of NK₉-positive cells were highest in LIS. The distribution of T lymphocytes (OKTii + ve), helper T cells (OKT₄+ ve), suppressor T celts (OKT8 + ve), Langerhans cells (OKT6 + ve) and activated T cells (anti-Tac + ve) in LIS differed from those in DLE, SLE and allergic contact reactions. However, the number of circulating NK cells (large granular lymphocytes) and the NK activity in peripheral blood were normal in LIS. We conclude that in LIS a distinct type of T cell activation occurs; the cause of this remains to be determined.     

Clinically relevant patch test reactions in children--a United States based study

Allergic contact dermatitis in the pediatric population is more common than previously recognized, with recent prevalence estimates of positive patch test reactions in the range of 14-70% of children patch tested. The aim of this study was to confirm the prevalence of clinically relevant allergic contact dermatitis in children at two referral centers and determine the most common contact allergens. We performed a retrospective case series analysis of 65 symptomatic children (35 girls and 30 boys) aged 1-18 years old who were patch tested over a 5-year period for recalcitrant dermatitis. Positive patch test reactions were noted in 54 of the 65 children (prevalence rate of 83%) to 80 different allergens. Fifty children (77%) had positive reactions which were determined to be of "definite" or "probable" current clinical relevance. We conclude that the diagnosis of allergic contact dermatitis to specific relevant allergens is common in children referred for patch testing and that contact allergy should be considered in all children with recalcitrant dermatitis. With this article, we review the literature and present a US based study regarding the clinical relevance of positive patch test reactions in children.     

Fc epsilon R11/CD23 receptor distribution in patch test reactions to aeroallergens in atopic dermatitis.

There is increasing evidence that exposure to organic allergens may induce or exacerbate lesional skin in patients with atopic dermatitis. In this study, patients with atopic dermatitis were patch tested to 11 common organic allergens and to control chambers containing 0.4% phenol and 50% glycerin in 0.9% saline. In biopsies from positive patch test reactions, patch test control skin, lesional eczematous and non-lesional skin from atopic individuals, and normal skin from non-atopic volunteers, the presence and distribution of macrophages (RFD7+), dendritic cells (RFD1+), and Langerhans cells, and the expression of the low-affinity receptor for IgE (CD23) were investigated. In patch test reactions and lesional skin samples, inflammatory infiltrates of diffusely distributed macrophages (RFD7+), dendritic cells (RFD1+), T lymphocytes (RFTmix+), and Langerhans cells (CD1+) were seen, the latter being present in both the epidermis and the dermis. The numbers of Langerhans cells were reduced in the epidermis and increased in the dermis in patch test reactions and lesional skin compared to their controls. Double staining revealed a change in the distribution of CD23 antigen. In patch test control and non-lesional biopsies many macrophages and only a few Langerhans cells within the dermal infiltrates expressed this antigen. In patch test reaction and lesional skin samples, however, the proportion of CD23+ dermal Langerhans cells had increased compared to macrophages. Furthermore, in these latter samples an increased proportion of dermal CD1+ cells expressed the dendritic cell (RFD1+) marker. These results show that following antigen challenge there are marked similarities between the phenotype of the cellular infiltrate in patch test reaction and lesional skin biopsies, and also demonstrate a changing distribution of CD23 on antigen-presenting cells.