Factors associated with severity of atopic dermatitis - a Finnish cross-sectional study.

BACKGROUND: Severity-associated factors in atopic dermatitis (AD) have focussed on early onset, concomitant atopic diseases, markers of Th2-shifted inflammation and filaggrin mutations. OBJECTIVES: To investigate factors associated with severe AD in Finnish patients. METHODS: We conducted a single-centre, cross-sectional observational study with 502 AD patients aged 4.79 to 79.90 years (mean 32.08 years). Disease severity was assessed with the Rajka-Langeland severity score and EASI and associated clinical signs were evaluated. Data regarding onset, relatives, atopic and other comorbidities was gathered retrospectively. We investigated total serum IgE-levels, a panel of filaggrin null mutations and functional variants of genes associated with skin barrier defects. RESULTS: Factors more frequent in severe AD included early onset (P = 0.004, 95%CI 0.000-0.024), male sex (P = 0.002, 95%CI 0.000-0.11), history of smoking (P = 0.012, 95%CI 0.000-0.024), concomitant asthma (P = 0.001, 95%CI 0.000-0.011), palmar hyperlinearity (P = 0.013, 95%CI 0.014-0.059), hand dermatitis (P = 0.020, 95%CI 0.000-0.029) and history of contact allergy (P = 0.042, 95%CI 0.037-0.096). Body mass indices (P < 0.000, 95%CI 0.000-0.011) and total serum IgE-levels (P < 0.000, 95%CI 0.000-0.011) were higher in severe AD. No differences were observed for allergic rhinitis, allergic conjunctivitis, food allergy, peanut allergy, prick positivity, keratosis pilaris, history of herpes simplex infections, filaggrin null mutations and other gene variants. CONCLUSIONS: Severity determinants in Finnish patients seem to be early-onset, male sex, smoking, overweight, concomitant asthma, palmar hyperlinearity, hand dermatitis and high IgE-levels. A sub-typing of patients in relation to confirmed severity determinants may be useful for course prediction, prognosis and targeted AD management.

Skin Biomes.

The cutaneous microbiome has been investigated broadly in recent years and some traditional perspectives are beginning to change. A diverse microbiome exists on human skin and has a potential to influence pathogenic microbes and modulate the course of skin disorders, e.g. atopic dermatitis. In addition to the known dysfunctions in barrier function of the skin and immunologic disturbances, evidence is rising that frequent skin disorders, e.g. atopic dermatitis, might be connected to a dysbiosis of the microbial community and changes in the skin microbiome. As a future perspective, examining the skin microbiome could be seen as a potential new diagnostic and therapeutic target in inflammatory skin disorders.

Contact sensitizer 2,4-dinitrochlorobenzene is a highly potent human TRPA1 agonist.

2,4-Dinitrochlorobenzene (DNCB) is widely used in human clinical studies and in experimental animal studies to evoke allergic contact dermatitis. 2,4-Dinitrochlorobenzene is a potent immunogen capable of inducing contact sensitization in all humans exposed. However, the mechanism by which DNCB evokes such symptoms is presently unknown. TRPA1 is a nonselective cation channel that is expressed in peptidergic sensory neurons and fibroblasts. TRPA1 activation was recently implicated in the pathophysiology of atopic dermatitis especially in transducing cutaneous itch signals. Here, we test the hypothesis that DNCB acts as a TRPA1 agonist and thereby evokes allergic symptoms. We found that DNCB activates human TRPA1 dose dependently in FLIPR experiments with an EC50 of 167 nM, an effect that was fully blocked by selective TRPA1 antagonists Chembridge-5861528 and A-967079. Similarly, DNCB activated nonselective TRPA1 current in patch clamp studies. Neutralization of 3 critical cysteines in TRPA1 resulted in a loss of DNCB agonism.

Long-term follow-up study of occupational hand eczema.

BACKGROUND: Long-term follow-up studies on the prognosis and consequences of occupational hand eczema (OHE) and the prognostic risk factors for persistent OHE are sparse. OBJECTIVES: To determine the medical and occupational outcome after a follow-up of 7-14 years in 605 patients diagnosed with OHE and to identify the prognostic risk factors for the continuation of hand eczema. METHODS: Patients examined at the Finnish Institute of Occupational Health in 1994-2001 completed a follow-up questionnaire 7-14 years after diagnosis. RESULTS: The hand eczema had healed (no eczema during the last year) in 40% of patients with OHE. The duration of hand eczema before diagnosis was strongly associated with the continuation of eczema. Age, sex and diagnosis (allergic or irritant contact dermatitis) were not associated with the prognosis, but skin atopy, and especially respiratory atopy, were correlated with the continuation of hand eczema. Contact allergies in general were not risk factors for persistent OHE, but the presence of a work-related chromate allergy was associated with poor healing. A total of 34% of patients had changed their occupation due to OHE, and their long-term prognosis was better than those who had not. The hand eczema of patients originally in food-related occupations continued on an unfavourable course. CONCLUSIONS: In the logistic model, risk factors for the continuation of OHE were a long duration of hand eczema before diagnosis, respiratory atopy, skin atopy, and continuation in the same occupation. Those who ended up changing occupation due to their OHE had a better medical and economic prognosis.

Scientific rationale for the Finnish Allergy Programme 2008-2018: emphasis on prevention and endorsing tolerance.

In similarity to many other western countries, the burden of allergic diseases in Finland is high. Studies worldwide have shown that an environment rich in microbes in early life reduces the subsequent risk of developing allergic diseases. Along with urbanization, such exposure has dramatically reduced, both in terms of diversity and quantity. Continuous stimulation of the immune system by environmental saprophytes via the skin, respiratory tract and gut appears to be necessary for activation of the regulatory network including regulatory T-cells and dendritic cells. Substantial evidence now shows that the balance between allergy and tolerance is dependent on regulatory T-cells. Tolerance induced by allergen-specific regulatory T-cells appears to be the normal immunological response to allergens in non atopic healthy individuals. Healthy subjects have an intact functional allergen-specific regulatory T-cell response, which in allergic subjects is impaired. Evidence on this exists with respect to atopic dermatitis, contact dermatitis, allergic rhinitis and asthma. Restoration of impaired allergen-specific regulatory T-cell response and tolerance induction has furthermore been demonstrated during allergen-specific subcutaneous and sublingual immunotherapy and is crucial for good therapeutic outcome. However, tolerance can also be strengthened unspecifically by simple means, e.g. by consuming farm milk and spending time in nature. Results so far obtained from animal models indicate that it is possible to restore tolerance by administering the allergen in certain circumstances both locally and systemically. It has become increasingly clear that continuous exposure to microbial antigens as well as allergens in foodstuffs and the environment is decisive, and excessive antigen avoidance can be harmful and weaken or even prevent the development of regulatory mechanisms. Success in the Finnish Asthma Programme was an encouraging example of how it is possible to reduce both the costs and morbidity of asthma. The time, in the wake of the Asthma Programme, is now opportune for a national allergy programme, particularly as in the past few years, fundamentally more essential data on tolerance and its mechanisms have been published. In this review, the scientific rationale for the Finnish Allergy Programme 2008-2018 is outlined. The focus is on tolerance and how to endorse tolerance at the population level.

Transforming growth factor-beta/Smad3 signalling regulates inflammatory responses in a murine model of contact hypersensitivity.

BACKGROUND: Transforming growth factor (TGF)-beta is an important modulator of immune functions and cellular responses, such as differentiation, proliferation, migration and apoptosis. The Smad proteins, which are intracellular TGF-beta signal transducers, mediate most actions of TGF-beta. OBJECTIVES: This study examines the role of Smad3 in a murine model of contact hypersensitivity (CHS). METHODS: The CHS response to oxazolone was studied in Smad3-deficient mice. The ear swelling response was measured and skin biopsies from oxazolone-sensitized skin areas were obtained for RNA isolation, immunohistochemical analyses and histology. Ear draining lymph nodes were collected for RNA isolation and proliferation tests. Quantitative real-time polymerase chain reaction was used to quantify mRNA expression of cytokines, chemokines and transcription factors. Results The expression of proinflammatory [interleukin (IL)-1beta, tumour necrosis factor-alpha, IL-6], Th2 (IL-4) and Th17 type cytokines (IL-17), as well as regulatory components (TGF-beta, Foxp3) increased significantly at the mRNA level in the skin of oxazolone-treated Smad3-/- mice when compared with wild-type controls. The expression of the Th1 type cytokine IFN-gamma and the chemokines CXCL9 and CXCL10 was, however, unaffected by the lack of Smad3. The number of neutrophils and expression of the chemokines CCL3 and CXCL5, which are both involved in neutrophil recruitment, were increased in mice lacking Smad3. Also Th2 type chemokines CCL24, CCL3 and CXCL5 were increased in the skin of Smad3-/- mice compared with wild-type mice. In the lymph nodes, mRNA of IL-1beta and IL-17, but not IL-4, TGF-beta or Foxp3, was increased in Smad3-/- mice during the CHS response. CONCLUSIONS: The lack of intact TGF-beta signalling via Smad3 results in an increased proinflammatory, Th2 and Th17 type response in the skin, as well as increased expression of regulatory elements such as TGF-beta and Foxp3. Understanding the role of Smad3 in the CHS response may offer treatment and prevention strategies in this often disabling disease.

Repeated epicutaneous exposures to ovalbumin progressively induce atopic dermatitis-like skin lesions in mice.

BACKGROUND: Atopic dermatitis (AD) is a chronic skin disease in which environmental factors play a great role. A widely used murine model for AD has provided a useful tool to study the disease. OBJECTIVE: The purpose of this study is to investigate kinetically the induction of this AD model and the processes involved in the development of AD due to extrinsic allergen exposures. METHODS: BALB/c mice were epicutaneously exposed to ovalbumin (OVA) for 3 weeks; each week was separated by a 2-week resting period. Mice were killed after each exposure week. Skin biopsies and blood were obtained for histological study, RNA isolation and antibody analysis. RESULTS: There was a progressive and significant thickening of the epidermis and dermis in OVA-exposed mice. Significantly increased dermal cell infiltration of eosinophils, mast cells and total inflammatory cells, including CD3 and CD4 cells, was found after each OVA exposure week. Total IgE, IgG2a and OVA-specific IgE were significantly increased after the second and third exposure week, while OVA-specific IgG2a was significantly induced after the third exposure week. Gradual and/or significant increases in mRNA expression of IL-1beta, TNF-alpha, IL-4, IL-10, IL-13, IFN-gamma and IL-12p35 were found after each exposure week. Chemokines and their receptors involved in both T-helper type 1 (Th1)- and Th2-type cell recruitment (CCL1, CCL8, CCL11, CCL24, CXCL9, CXCL10, CCR1, CCR3, CCR5, CCR8 and CXCR3) were up-regulated significantly at different time-points. CONCLUSION: This study provides an insight into the dynamic nature and time-dependent transition of skin inflammation and systemic immune responses in a murine AD model induced by repeated epicutaneous exposures to OVA.

Patch test reactions to cosmetic allergens in 1995-1997 and 2000-2002 in Finland--a multicentre study.

Contact sensitivity to cosmetics is common, but the sensitizing chemicals vary between countries and study periods. The present survey aimed at revealing the recent trends in patch test sensitivity with cosmetic chemicals in Finland. We report a retrospective multicentre survey of patch test reactions focusing on cosmetic-related substances and comparing the test results in 1995-97 with those in 2000-02. The most striking increases in the frequency of the patch test sensitivity were found with balsam of Peru and propolis from 4.0% to 6.2% (P < 0.001) and from 0.5% to 1.4% (P < 0.001), respectively, whereas the most prominent decreases were found with methylchloro/methylisothiazolinone and chlorhexidine diglugonate from 2.4% to 1.3% (P < 0.001) and from 1.2% to 0.5% (P < 0.001), respectively. The level of patch test sensitivity to methyldibromo glutaronitrile increased, although not significantly, from 1.0% to 1.5%. An increasing tendency was also found with hair dye chemicals 4-aminophenol and toluene-2,5-diamine or toluene-2,5-diamine sulfate from 1.3% to 3.8% and from 1.4% to 5.2%, respectively, while such a tendency was not found among permanent wave chemicals. The sensitivity level of fragrance mix remained the same (6% - 7%). We conclude that surveys revealing the state of sensitivity to cosmetic chemicals should be performed periodically in different countries.

Phthalic anhydride allergy: development and characterization of optimized hapten-carrier conjugates for improved diagnosis.

BACKGROUND: At present the diagnosis of IgE-mediated hypersensitivity to phthalic anhydride (PA) is based on conjugates that are not characterized or standardized. The aim of this study was to develop optimized and molecularly characterized PA conjugates that can be used to improve the diagnosis of PA-allergy. METHODS: The PA conjugates were synthesized and the number of haptens bound on a carrier protein was estimated by matrix-assisted laser desorption/ionization time of light (MALDI-TOF) mass spectrometry. The ability of conjugates to bind IgE and IgG antibodies was measured by enzyme-linked immunosorbent assay (ELISA). Reactivity of the conjugates in vivo was evaluated by skin prick testing. RESULTS: The most active IgE-binding conjugates had a PA : HSA molar ratio of 80 : 1. In the optimal conjugates the average numbers of PA haptens per carrier molecule of human serum albumin (HSA) were 14-16. In ELISA, all 13 patients and none of the 20 controls had IgE antibodies to optimized PA conjugate. The sensitivity and specificity of the ELISA was comparable to commercial CAP RAST. PA conjugates elicited positive test results in skin prick testing showing that conjugates are immunologically active also in vivo. CONCLUSIONS: These results indicate that optimized and molecularly characterized PA-HSA conjugates can be used both in vitro and in vivo assays to improve the diagnosis of PA allergy.

A multicenter study of patch test reactions with dental screening series.

BACKGROUND: Dental products contain many allergens, and may cause problems both for patients undergoing dental treatment and for dental personnel because of occupational exposure. Individual patch test clinics may not study sufficient numbers of patients to collect reliable data on uncommon allergens. OBJECTIVE: To collect information on dental allergens based on a multicenter study. MATERIALS AND METHODS: The Finnish Contact Dermatitis Group tested more than 4,000 patients (for most allergens, 2,300 to 2,600 patients) with dental screening series. Conventional patch testing was performed. The total number and percentage of irritant (scored as irritant [IR] or doubtful [?]) and allergic (scored as +, ++, or +++) patch test reactions, respectively, were calculated, as well as the highest and lowest percentage of allergic patch test reactions recorded by the different patch test clinics. A reaction index (RI) was calculated, giving information on the irritancy of the patch test substances. RESULTS: The most frequent allergic patch test reactions were caused by nickel (14.6%), ammoniated mercury (13%), mercury (10.3%), gold (7.7%), benzoic acid (4.3%), palladium (4.2%) and cobalt (4.1%). 2-hydroxyethyl methacrylate (2.8%) provoked most of the reactions caused by (meth)acrylates. Menthol, peppermint oil, ammonium tetrachloroplatinate, and amalgam alloying metals provoked no (neither allergic nor irritant) patch test reactions. CONCLUSION: Patch testing with allergens in the dental screening series, including (meth)acrylates and mercury, needs to be performed to detect contact allergy to dental products.

Cryptococcosis during systemic glucocorticosteroid treatment.

Cryptococcosis is an opportunistic infection caused by a fungus, Cryptococcus neoformans. It is usually seen in immunocompromised patients with AIDS, leukaemia, lymphoma, sarcoidosis or immunosuppressive treatments. We describe a patient who was treated with systemic glucocorticosteroids for 4 years because of lung sarcoidosis. During the last year of treatment, a papular eruption developed which later became ulcerative. In a histopathological examination of a skin biopsy, there was granulomatous inflammation, and the disease was treated as sarcoidosis without success. After 1 year's unsuccessful treatment, another skin biopsy and skin fungal culture revealed C. neoformans. Cryptococcal antigen was found in blood and cerebrospinal fluid, too. The patient was successfully treated first with an amphotericin-B-flucytosine combination and later with fluconazole.

Tacrolimus ointment improves psoriasis in a microplaque assay.

Tacrolimus (FK506) is an effective and well tolerated immunosuppressant used to prevent allograft rejection. We describe the evaluation of two tacrolimus ointment formulations for treatment of chronic plaque-type psoriasis. This was a microplaque assay with randomized, double-blind design. Sixteen patients (15 men, one woman, all white and 28-69 years old) with chronic plaque-type psoriasis participated. Six different ointments were applied to discrete microplaques, 17 mm in diameter, on a descaled psoriasis lesion: these were tacrolimus ointment with diisopropyl adipate as penetration enhancer, tacrolimus ointment without diisopropyl adipate, 0.1% betamethasone 17alpha-valerate ointment, 0.005% calcipotriol ointment and, as controls, the ointment bases for tacrolimus and betamethasone. Ointments were reapplied and the area was sealed every 2-3 days during the 14-day treatment period. After 7 and 14 days, erythema and infiltration were graded on a scale of 0-4, and superficial blood flow was measured with a laser Doppler flowmeter. Epidermal thickness was measured histologically at the end of treatment. Compared with the vehicle controls, sites treated with tacrolimus ointment (with or without penetration enhancer) showed a significant reduction in erythema and infiltration (P < 0. 001), a significant reduction in superficial blood flow (P < 0.01) and a significant decrease in epidermal thickness (P < or = 0.001). Results for betamethasone and calcipotriol, when compared with the vehicle controls, were similar. These results suggest that, under conditions of descaling and occlusion, tacrolimus ointment is effective in the treatment of psoriasis.

Tacrolimus ointment does not affect collagen synthesis: results of a single-center randomized trial.

We conducted a randomized, double-blind, placebo-controlled trial to assess the atrophogenicity of tacrolimus ointment. In a combined group of atopic dermatitis patients (n = 14) and healthy volunteers (n = 12), 0.3% tacrolimus, 0.1% tacrolimus, betamethasone-valerate, and a vehicle control were applied in a randomized order to nonsymptomatic, 4 cm x 4 cm regions of abdominal skin. After 7 d of treatment under occlusion, the carboxy- and amino-terminal propeptides of procollagen I (PICP, PINP) and the amino-terminal propeptide of procollagen III (PIIINP) were measured from suction blister fluid with specific radioimmunoassays. In addition, ultrasound measurements of skin thickness were taken. Betamethasone-treated areas showed median PICP, PINP, and PIIINP concentrations of 17.0%, 17.6%, and 39.5% of the vehicle control at the end of the treatment period, respectively, whereas the 0.1% and 0.3% tacrolimus-treated areas showed median concentrations of approximately 100% of the vehicle control (p < 0.001). Betamethasone was also the only treatment to reduce skin thickness; the median decrease in skin thickness was 7.4% relative to 0.1% tacrolimus, 7.1% relative to 0.3% tacrolimus, and 8.8% relative to the vehicle control (p < 0.01). Results for atopic dermatitis patients and healthy volunteers were similar. These findings suggest that tacrolimus does not cause skin atrophy.

Topical FK506 suppresses cytokine and costimulatory molecule expression in epidermal and local draining lymph node cells during primary skin immune responses.

Recently, it has been shown that the immunosuppressive macrolide lactone, FK506, exerts good therapeutic efficacy in inflammatory skin diseases. The aim of this study was to analyze the influence of topical FK506 on molecular (IL-1alpha, IL-1beta, IL-2, IL-4, IL-12 p35, IL-12 p40, macrophage inflammatory protein-2 (MIP-2), granulocyte-macrophage CSF (GM-CSF), TNF-alpha, and IFN-gamma) and cellular (I-A+/CD80+, I-A+/CD54+, I-A+/CD69+, I-A+/B220+, and CD4+/CD25+) events in epidermal (EC) and local draining lymph node (LNC) cells during primary contact hypersensitivity responses. Cytokine mRNA levels for IL-1alpha, IL-1beta, GM-CSF, TNF-alpha, MIP-2, and IFN-gamma in EC and for IL-2, IL-4, IL-12 p35, IL-12 p40, and IFN-gamma in LNC were increased and resulted in significant LNC proliferation during oxazolone-induced contact hypersensitivity. Topical FK506 treatment dose-dependently suppressed oxazolone-induced LNC proliferation. This effect was correlated with decreased IL-1alpha, IL-1beta, GM-CSF, TNF-alpha, MIP-2, and IFN-gamma mRNA expression within the epidermis and decreased IL-12 p35 and p40 mRNA expression in LNC. Further analysis of the LNC cytokine pattern revealed that the production of both Thl (IFN-gamma and IL-2) and Th2 (IL-4) cytokines was dramatically impaired after topical FK506 treatment. Flow cytometric analysis showed that topical FK506 decreased the population of epidermis-infiltrating CD4+ T cells and suppressed the expression of CD54 and CD80 on I-A+ EC and LNC during hapten-induced contact hypersensitivity. Furthermore, topical FK506 profoundly impaired oxazolone-induced up-regulation of CD25 expression on CD4+ LNC and dramatically decreased hapten-induced expansion of I-A+/B220+ and I-A+/CD69+ LNC subsets. In conclusion, these results give new insights into the mechanisms of action of topical FK506 treatment.