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Local nasal immunotherapy for birch allergic rhinitis with extract in powder form.

BACKGROUND: Traditional subcutaneous immunotherapy has been proved effective in birch pollenosis. It has, however, some drawbacks as systemic reactions, which are rare but important. Local nasal immunotherapy (LNIT) represents a potential safer route of allergen administration. OBJECTIVE: To study the clinical efficacy and safety of local nasal immunotherapy by means of an extract in powder form as treatment of birch allergic rhinitis. METHODS: Thirty birch allergic patients have been selected on the basis of a positive history, skin test, radioallergosorbent test assay (RAST) and specific nasal challenge. Two 15 patient groups were randomly assigned to the active treatment or to the placebo one. Treatment lasted 22 weeks (14 for the build-up phase and eight for maintenance period) and symptoms were recorded during the treatment and the birch pollen season. RESULTS: The clinical efficacy of LNIT is suggested by a significant reduction of medication score only in the treated group during the pollen season, although the symptom score was significantly lower in the treated group for 1 week only. Moreover, a significant increase of specific nasal threshold dose was observed after treatment only in the active treated group. Mild adverse reaction to LNIT, limited to the upper respiratory tract, were reported during the treatment in the active group, but they did not interfere with LNIT schedule. No asthmatic or systemic reaction were observed. CONCLUSIONS: This study indicates that LNIT with allergen in powder form has proven clinically effective in the treatment of birch allergic rhinitis. Further studies are needed to establish whether this treatment can be considered a real alternative to the traditional subcutaneous immunotherapy in birch allergic rhinitis.

Administration, Intranasal↗

Winter pollinosis in Paris.

Pollen is rarely investigated as a cause of winter respiratory symptoms. Infectious coryza and asthma are particularly common during winter, and it has been shown that environmental antigens can cause at least some cases in Paris. Recent experimental data from Calhoun et al. (1991) indicate that pollen may act synergistically with viral respiratory infections, which are particularly prevalent in winter. In the present study, we investigated, in 130 consecutive patients presenting with winter aggravation of asthma or rhinitis, winter pollinosis by skin test, radioallergosorbent test (RAST), and specific endonasal challenge test. Totals of 35, 24, and 21 patients reacted positively in skin, RAST (> 0.70 PRU/ml), and endonasal tests, respectively. Clinical features during the season established the diagnosis of winter pollinosis in 20 cases; it was due to alder pollen in 10 patients and hazel pollen in 12. The positive predictive value of the skin test was only 0.57, as compared with 0.86 for the specific endonasal test, which had a negative predictive value of 1. Our results indicate that hazel and alder pollens should be prick-tested for more often as causes of winter respiratory symptoms in Paris, even if similar manifestations were absent during previous winters, were previously present during spring or summer, or were both absent in previous winters and present in spring or summer.

Adolescent↗

Allergy risk in an enzyme producing plant: a retrospective follow up study.

OBJECTIVE: To investigate the risk of enzyme sensitisation and clinical allergy in workers exposed to enzymes at Novo Nordisk A/S. METHODS: The study was a retrospective follow up study based on medical history and test data originally collected at routine screenings for enzyme allergy by the Occupational Health Service (OHS) of Novo Nordisk A/S during the period 1970-92. Workers were exposed to proteases, lipases, cellulases, and carboxyhydrases. Medical records of 3815 subjects were registered in the OHS database. According to criteria including possible enzyme exposure, allergy tests at the time of engagement, and participation in the allergy screening programme 1064 were selected for the present study. Outcomes were allergy symptoms, specific IgE test (radioallergosorbent test (RAST)) to enzymes, skin test reactions to common allergens and enzymes, forced expiratory volume in one second (FEV1), and forced vital capacity (FVC). Potential risk factors were smoking habits, workplace, type of job, age, and sex. RESULTS: Sensitisation occurred to all types of enzymes handled in the plant, most often in production areas and laboratories; 8.8% developed clinical enzyme allergy during the first three years of employment. The risk declined during the period. The frequency of enzyme sensitisation, expressed as RAST values > 0.5 SU, was 36%, and the frequency of significant RAST values > or = 2 SU was 8%. Ranking diagnoses of enzyme allergy by severity, the frequency of asthma was 5.3%, rhinitis 3.0%, and urticaria 0.6%. Half of the cases occurred within the first 15 months of exposure. Smoking was an independent risk factor for clinical enzyme allergy (odds ratio (OR) = 2.3 (95% exact confidence interval (95% CI) 1.4 to 3.9), measurable RAST > or = 0.5 SU (OR = 1.5 (95% CI 1.1 to 2.1)), and RAST > or = 2 SU (OR = 4.5 (95% CI 2.2 to 8.4)). Atopic predisposition at the time of engagement was not a significant risk factor for enzyme allergy. This could be due to various selection mechanisms.

Cohort Studies↗

Immunotherapy: rationale and mechanisms.

Immunotherapy is defined as the controlled exposure to known allergens to reduce the severity of the allergic response. Although available since 1910, its exact mechanisms of action is not known but may involve an increase in allergen-specific IgG antibodies, a decrease in IgE synthesis, and alteration in T-lymphocyte activity. Immunotherapy is indicated in patients with proven allergy who have significant symptoms. It may be used together with pharmacologic measures but is relatively contraindicated in patients receiving beta-blocker therapy. Immunotherapy may be continued during pregnancy and should not be initiated in patients with autoimmune diseases or in human immunodeficiency virus-positive patients. Selection of appropriate diagnostic tests is important. Before immunotherapy is considered, there are two recommended in vivo tests (combined prick and intradermal skin test, and skin end point titration) and two recommended in vitro tests (radioallergosorbent test [RAST] and enzyme-linked immunosorbent assays [ELISA]), all equally safe and sensitive. After appropriate test interpretation, treatment is initiated with slowly escalating doses of allergen. Effects are often apparent in 3 to 6 months and, after continuation for 3 to 5 years, patients usually achieve lasting benefit.

Contraindications↗

[Occupational diseases caused by exposure to sensitizing metals].

Diseases caused by occupational exposure to sensitizing metals including platinum (Pt), rhodium (Rh), nickel (Ni), chromium (Cr), cobalt (Co), gold (Au), mercury (Hg), zirconium (Zr) and beryllium (Be) are reviewed. Allergic reactions induced by the metals are described according to the classification by Coombs and Gell. Metals with unproven sensitizing potential are not discussed if reports on these are either very rare or devoid of convincing evidence for allergic involvement. The sensitizing metals are haptens which are not themselves able to act as antigens. There is evidence that combination of the metals with circulating or tissue protein gives rise to new antigens. An alternative hypothesis is that these metals interfere with the antigen recognition step of the immune response. Immunomodulatory effects or immunotoxicity of the metals may be also involved in metal-induced hypersensitivity. Occupational exposure to Pt, Rh, Ni, Cr, and Co causes allergic asthma via type I allergic reaction in which serum from affected individuals shows specific IgE antibodies against mental-human serum albumin conjugates. Some rheumatoid arthritis patients treated with gold salt therapy develop glomerulonephritis, thrombocytopenia, or agranulocytosis, which arise from type II and/or type III allergic reactions. Occupational exposure to mercury causes glomerulonephritis in which involvement of type III reaction is suggested. Type IV hypersensitivity reaction of the skin also takes place following exposure to the metals: allergic contact dermatitis is evoked by exposure to Ni, Cr, Co, Rh, and Hg; cutaneous granuloma is formed by contact with Zr and Be. Be is also a sensitizer of the lungs, resulting in granulomatous disease. Diagnosis of metal-induced allergic diseases is made on the basis of allergological tests with metal antigens including skin tests, radioallergosorbent test for specific antibody, lymphocyte transformation test, macrophage migration inhibition test, and provocation test. Atopy is a predisposing factor and smoking is a risk factor for developing metal-induced asthma. Evidence for genetic factors in the development of metal contact dermatitis is conflicting, although animal models implicate genetic factors in skin sensitization with some metals and respiratory sensitization with Be. Skin irritation, forearm injury, complication with atopic dermatitis and concomitant sensitization to other agents are determinants for prognosis of the dermatitis. Epidemiological reports of occupational diseases from allergic reactions to metals in industries are reviewed with respect to prevalence and allergic manifestations. There is a report on a clinical trial of hyposensitization with Pt in a platinum asthma patient. Predictive methods for evaluating sensitization potential of metals have been developed and new methods, which quantify potential more objectively, are sought.

Allergens↗

Drug effects on antigen-induced release of high molecular weight-neutrophil chemotactic activity and histamine in nasal secretion from children with allergic rhinitis.

Five children with allergic rhinitis sensitive to house dust mite as documented by skin test, radioallergosorbent test, score and nasal provocation were studied. Patients were subjected to nasal challenge with 3.125, 6.25, 12.5, and 25 protein nitrogen micrograms per disc of house dust mite antigens and nasal secretions were collected by the filter paper method. Neutrophil chemotactic activity (NCA) and histamine content of the nasal secretions were measured. NCA and histamine were released in a dose- and time-dependent manner, and no significant correlation between NCA and histamine was revealed in each subject. Pretreatment with 5.2 mg of nasal disodium cromoglycate or 0.5 micrograms of nasal adrenaline 5 minutes before provocation totally inhibited mediator release upon nasal challenge with 12.5 micrograms of house dust mite. A dose of 100 micrograms of nasal beclomethasone dipropionate 5 minutes before challenge neither inhibited clinical symptoms nor mediator release; 100 micrograms x 3 times per day of nasal beclomethasone dipropionate for 3 days, however, significantly inhibited clinical symptoms and release of both NCA (p less than 0.05) and histamine (p less than 0.05). NCA eluted as a single peak with an estimated molecular weight of 600,000. These results suggest that high molecular weight-NCA may be involved in the pathogenesis of allergic rhinitis.

Allergens↗

Clinical and immunological evaluation of isocyanate-exposed workers.

Isocyanates are the most significant cause of occupational asthma in our country. To evaluate the prevalence of work-related respiratory symptoms and immunologic sensitization to it, we performed a questionnaire survey, allergy skin test, radioallergosorbent test (RAST) to toluene diisocyanate (TDI)-human serum albumin (HSA) conjugate and methacholine bronchial challenge test on 23 isocyanate-exposed employees and 9 unexposed controls working in a zipper factory. Six employees (26.1%) complained of work-related respiratory symptoms and three symptomatic workers showed significant bronchoconstrictions on TDI-bronchoprovocation test. Three (13%) asymptomatic workers had high specific IgE antibodies to TDI-HSA and none of the TDI-sensitive asthmatic workers had specific IgE antibody. One of the TDI-sensitive asthmatic workers showed a negative result on the initial methacholine bronchial challenge test, but bronchial hyperresponsiveness developed after the TDI challenge. It was suggested that TDI-sensitive asthma was noted in three (13%) of 23 exposed workers and that asymptomatic workers could have high specific IgE antibody. Measurement of the changes in bronchial hyperresponsiveness after the TDI challenge could be helpful to diagnose TDI-sensitive asthma.

Adult↗

Multicenter study on the prevalence of perennial allergic rhinitis and allergy-associated disorders.

Multicenter Study on the Prevalence of Perennial Allergic Rhinitis and Allergy-Associated Disorders This study was aimed to determine the prevalence of perennial allergic rhinitis (PAR) using the skin test, radioallergosorbent test (RAST), or multiple allergosorbent test (MAST) and to clarify the clinical aspects of the patients diagnosed as having PAR by the questionnaire survey and rhinologic examination. The 71,120 subjects who had visited the 23 otolaryngology clinics at the randomly selected tertiary referral hospitals in Korea between November 1, 1999 and April 30, 2000 were studied. PAR was diagnosed when subjects complained of two or more associated symptoms and the skin test, RAST, or MAST using perennial inhalant allergens was positive. The questionnaire survey and rhinologic examination were performed in subjects with PAR. The prevalence of PAR was 3.93%. We could find no significant difference in the prevalence of PAR between the two sexes. However, there was a significant difference in the prevalence of PAR between the child and adult groups. The chief complaints were, in order of decreasing frequency, nasal obstruction, watery rhinorrhea, and sneezing. There was a family history of PAR in 40.2% of the subjects. The 39.6% of the subjects had associated allergic diseases, being atopic dermatitis most common. In conclusion, the prevalence of PAR in tertiary referral hospitals in Korea is 3.93%. Many subjects with PAR have family history and appear to be associated with other allergic diseases.

Adult↗

Diagnosing rhinitis: allergic vs. nonallergic.

Allergic rhinitis, the most common type of rhinitis, generally can be differentiated from the numerous types of nonallergic rhinitis through a thorough history and physical examination. Allergic rhinitis may be seasonal, perennial, or occupational. The most common cause of nonallergic rhinitis is acute viral infection. Other types of nonallergic rhinitis include vasomotor, hormonal, drug-induced, structural, and occupational (irritant) rhinitis, as well as rhinitis medicamentosa and nonallergic rhinitis with eosinophilia syndrome. Since 1998, three large expert panels have made recommendations for the diagnosis of allergic and nonallergic rhinitis. Allergy testing (e.g., percutaneous skin testing, radioallergosorbent testing) is not necessary in all patients but may be useful in ambiguous or complicated cases.

Diagnosis, Differential↗

Prosopis juliflora pollen allergen induced hypersensitivity and anaphylaxis studies in guinea pigs.

In vivo and in vitro allergenic activities of Prosopis juliflora pollen allergens were measured in guinea pigs. Intracutaneous skin test showed an early wheal flare response and a late erythema-redness, sensitized with various concentrations (100, 50, 25, 5 and 1.5 micrograms/ml) of Prosopis juliflora pollen extract after administration of a challenging dose. A 50 micrograms/ml sensitizing dose of Prosopis juliflora pollen allergen gave optimum skin response as both early and late effects. The nature of immunochemical reactivity between pollen allergens and reaginic antibodies were further characterized by histamine release test, gel diffusion test, radioallergosorbent test and passive cutaneous anaphylaxis test. These tests confirm allergenicity caused by Prosopis juliflora pollen allergens and showed the binding of allergens with reaginic antibody and its regulation in guinea pigs.

Allergens↗

[Extrinsic and intrinsic asthma from childhood to early adult age. A 10-year follow-up].

The purpose of this study was to describe factors of potential importance for the outcome in children with intrinsic and extrinsic asthma. Of 85 consecutive children, five to 15 years of age, with asthma, 70 (82%) participated in a ten year follow up examination. At the time of referral all children underwent certain tests for asthma (case history, total IgE, skin prick tests, radioallergosorbent tests (RAST) and specific bronchial provocations). On the basis of these tests 24 children had intrinsic asthma and 46 extrinsic asthma. At the follow up examination 60 of the 70 adults (86%; 20 with intrinsic asthma) had current symptoms; 54 of the 60 (90%; 18 with intrinsic asthma) were receiving maintenance therapy. Both FEV1 %pred (from 73% +/- 19% to 92% +/- 17%) and FEV1/FVC (from 75% +/- 13% to 80% +/- 12%) increased significantly from childhood to early adulthood (p < 0.0002 and p < 0.001, respectively); a corresponding amelioration of symptoms was also observed (p < 0.0001). In children with intrinsic asthma the outcome seems to be predicted by a combination of the initial frequency of symptoms (p = 0.04), initial FEV1 (p = 0.001), active smoking (p = 0.001) and age at onset of respiratory symptoms (p = 0.001), whereas the initial FEV1 (p < 0.001) seems to be a strong predictor for the outcome in children with extrinsic asthma. These findings suggest that the pathogenetic mechanisms underlying intrinsic and extrinsic asthma in children may differ.

Adolescent↗

Manifestations of food allergy: evaluation and management.

The term "food allergy" refers to adverse immunologic reactions to food. Food allergy is usually mediated by IgE antibody directed to specific food proteins, but other immunologic mechanisms can also play a role. The primary target organs for food allergic reactions are the skin, the gastrointestinal tract and the respiratory system. Both acute reactions (hives and anaphylaxis) and chronic disease (asthma, atopic dermatitis and gastrointestinal disorders) may be caused or exacerbated by food allergy. The foods most commonly causing these reactions in children are milk, egg, peanuts, soy, wheat, tree nuts, fish and shellfish; in adults, they are peanuts, tree nuts, shellfish and fish. The diagnosis of food allergy requires a careful search for possible causes, confirmation of the cause(s) with supporting tests, including specific tests for IgE (i.e., prick skin tests, radioallergosorbent tests) and, in some cases, oral food challenges. Treatment consists of elimination of the causal food(s) along with medical treatment, including the prompt self-administration of epinephrine in the event of a serious reaction.

Diagnosis, Differential↗

Epidemiology of insect venom sensitivity.

The prevalence of insect sting reaction and of venom sensitization in adults is unknown. We report the results of intake evaluation of a stratified random sample of a large adult population previously studied for the determinants of atopic disease. In 269 subjects, the prevalence of systemic allergic sting reactions was 3.3% and 26.5% had IgE antibodies to venom demonstrated by skin test or radioallergosorbent test. Asymptomatic sensitization (positive venom skin test) was observed in 15% of subjects with no history of an allergic sting reaction. Positive venom skin tests were more frequent in men, in those with positive skin tests to inhalant allergens, and in subjects aged 20 through 29 years. A positive venom skin test or radioallergosorbent test was more frequent in subjects who had been stung within the previous 3 years (35%) than in those stung more than 3 years before (20%). We conclude that both systemic allergic reactions to insect stings and asymptomatic sensitivity to venom are common and that most affected persons never seek medical advice. The significance of asymptomatic venom sensitization is unknown.

Adult↗

Latex allergy. Review of 44 cases including outcome and frequent association with allergic hand eczema.

BACKGROUND AND DESIGN: Latex allergy is a type I reaction to natural rubber latex (NRL) proteins with clinical manifestations ranging from contact urticaria to fatal anaphylaxis. Previous US studies on NRL allergy have largely been reported by allergists with little detailed information on concomitant hand eczema, contact allergy, or on outcome. The charts of all patients with latex allergy seen between 1980 and 1994 in a dermatology department are reported with results of history; prick, scratch, wear, and patch tests; latex radioallergosorbent test; and follow-up questionnaire. RESULTS: There were 44 patients (37 female) with NRL allergy; 34 of whom had atopy. In 38 it was occupationally related, with all but two in health-related professions. Of the six nonoccupational cases, three had spina bifida. Twenty-nine had local skin reactions of urticaria and/or pruritus; seven, anaphylaxis; and eight, contact urticaria with other systemic symptoms. The diagnosis was based on a positive prick or scratch test to NRL in 37 cases, a class 2 or greater latex radioallergosorbent test in five cases, and strongly positive wear test results to an NRL glove in two cases. Thirty-six patients had hand eczema, with 26 having relevant positive patch test results that included glutaraldehyde, latex and vinyl gloves, and rubber chemicals. Follow-up revealed one patient quit work and eight changed jobs or tasks because of NRL allergy, 33 of 39 continued to have symptoms at work, and 12 had lost work time because of latex allergy symptoms. CONCLUSIONS: Latex allergy was frequently seen in health care or dental workers, which was frequently associated with systemic symptoms, hand eczema, and allergic contact dermatitis. Most continue to work, but remained symptomatic. Patients with NRL allergy should be provided information on nonlatex devices and latex avoidance in medical, dental, and occupational settings. Low-NRL allergen gloves should be worn by coworkers of health care workers with NRL allergy.

Adolescent↗

Atopic eczema and allergy.

Although the pathomechanisms of respiratory atopy are well established, the role of IgE-mediated hypersensitivity in the elicitation and maintenance of eczematous skin lesions in atopic eczema (AE) is still controversial. There is, however, evidence for exogenous elicitation of AE by contact with aero- or food allergens (house dust mite, cat, and so forth). Recent investigations show that epidermal Langerhans' cells bind IgE via different receptors, especially the high-affinity receptor (Fc epsilon RI), which is significantly more strongly expressed in lesional skin of AE compared with other inflammatory skin diseases including allergic contact dermatitis. The clinical relevance of IgE-mediated sensitization in AE has been evaluated by the so-called atopy patch test (APT). The APT shows a much higher specificity compared with the skin prick test and radioallergosorbent test. However, allergic reactions do not play a decisive role in every case of AE. Other factors, such as nonspecific skin irritability or psychosomatic interactions, have to be considered. The concept of "extrinsic" versus "intrinsic" types of AE seems attractive. The concept of AE starting with TH2 inflammation, becoming TH1 inflammation in chronicity, and finally progressing to an autoimmune disease with IgE antibodies against autologous epidermal proteins is very attractive. Based on new knowledge, new methods in diagnosis, treatment, and prevention will develop, including more effective avoidance strategies, more potent anti-inflammatory treatment (e.g., immunomodulation or topical immunophyllins), and new ultraviolet modalities. The new findings have given rise to a possible new classification of eczema/dermatitis. The concept of "patient management," including all aspects from avoidance to therapy, has gained acceptance.

Animals↗

Evaluating the relevance of aeroallergen sensitization in atopic eczema with the atopy patch test: a randomized, double-blind multicenter study. Atopy Patch Test Study Group.

BACKGROUND: IgE-mediated sensitization of questionable clinical relevance is routinely demonstrated in patients with atopic eczema (AE) by skin prick test or radioallergosorbent test (RAST). We report the results of a randomized, double-blind multicenter study in patients with AE on the relevance and technical aspects of aeroallergen patch testing (atopy patch test, APT). METHODS: Two hundred fifty-three adult patients with AE in remission were tested in 7 study centers on clinically uninvolved, unabraded back skin with 3000 to 10,000 PNU/g of Dermatophagoides pteronyssinus, cat dander, grass, birch, and mugwort pollen allergen extracts in petrolatum. After skin prick and RAST and a detailed history on aeroallergen-induced eczema flares was obtained, reading was done at 48 to 72 hours. RESULTS: Previous eczema flares after contact with specific allergens were reported by 10% (mugwort pollen) to 52% (D pteronyssinus) of patients. The percentage of clear-cut positive APT reactions ranged from 44% with D pteronyssinus to 5% with mugwort. Positive skin prick (36% to 65%) and RAST (49% to 75%) results were more frequent. APT results showed significant concordances with history, skin prick, and RAST for D pteronyssinus, cat dander, and grass pollen (P < .001). Optimal test concentrations were 5000 (grass pollen) and 7000 PNU/g (D pteronyssinus, cat dander). The APT had a higher specificity (69% to 92% depending on allergen) with regard to clinical relevance of an allergen compared with skin prick test (44% to 53%) and RAST (42% to 64%). CONCLUSION: Aeroallergens are able to elicit eczematous skin reactions after epidermal application. The relevance of aeroallergens for AE flares may be evaluated by APT.

Adolescent↗

Food allergy: when and how to perform oral food challenges.

In many situations, the diagnosis of food allergy rests simply upon a history of an acute onset of typical symptoms, such as hives and wheezing, following the isolated ingestion of a suspected food, with confirmatory laboratory studies of positive prick skin tests or Radioallergosorbent tests. However, the diagnosis is more complicated when multiple foods are implicated or when chronic diseases, such as asthma or atopic dermatitis, are evaluated. The diagnosis of food allergy and identification of the particular foods responsible is also more difficult when reactions are not mediated by IgE antibody, as is the case with a number of gastrointestinal food allergies. In these latter circumstances, well-devised elimination diets followed by physician-supervised oral food challenges are critical in the identification and proper treatment of these disorders. Because childhood food allergies to common allergenic foods such as milk, egg, wheat and soy are usually outgrown, oral food challenges are also an integral part of the long-term management of these children.

Antibody Specificity↗

Mite allergen (Der p 1) levels in houses of children with atopic dermatitis: the relationship with allergometric tests.

Several studies, in particular in adult groups, have evaluated the involvement of mites in the pathogenesis of atopic dermatitis (AD). This still remains controversial. The objective of this study was to determine the level of house dust mites (HDMs) in the beds of a group of children with AD and correlate these levels with their allergometric assessment. Forty-one children with AD underwent allergometric tests (prick test, patch test and radioallergosorbent test, RAST) and the concentration levels of HDMs in their homes were evaluated. Our data show that about half of the children (51%) with AD presented Dermatophagoides pteronyssinus positivity (prick test and/or RAST and/or patch test). Dust was collected in the period October-November from the children's beds, by the same two operators, using a dust-collection device. The dust mite level was tested by an enzyme-linked immunosorbent assay with antibody against Der p 1 allergen. Ten children (24%) presented a Der p 1 concentration > 2 microgram/g of dust (the value assumed to be a risk level for sensitization), 20 (49%) between 0.1 and 2 microgram/g and 11 (27%) < 0.1 microgram/g of dust. In the group with the highest Der p 1 concentration (> 2 microgram/g dust) nine children (90%) presented an allergometric D. pteronyssinus sensitivity, the difference with the other two groups being statistically significant at P < 0.018. The results of the present study show that the highest HDM concentrations were observed in the group with an allergometric D. pteronyssinus positivity (prick test and/or RAST and/or patch test). It is hypothesized that a higher HDM concentration may elicit D. pteronyssinus IgE sensitization and delayed hypersensitivity in children with AD.

Animals↗