Intradermal Test Reactions Research Articles

Humoral measurement of type‐1 hypersensitivity reactions to a commercialMalasseziaallergen

Malassezia pachydermatis is considered to be a contributing factor to canine atopic dermatitis (AD). The purpose of this study was to investigate the humoral response to a commercially produced M. pachydermatis extract. Fifteen atopic dogs with Malassezia overgrowth on the skin (MD), 16 atopic dogs without MD, three atopic dogs with overgrowth of Malassezia in the ears only (MO), and 12 normal dogs were intradermally tested with M. pachydermatis extract at 50, 100, 250, 500, 1000, 2000 and 4000 PNU mL(-1). All dogs were evaluated cytologically by cutaneous tape strip and bilateral ear exudate sampling to determine presence of MD or MO. Each had serum evaluated for anti-Malassezia IgE using three Malassezia extracts with an ELISA assay. The irritant threshold concentration at which healthy nonatopic dogs ceased to react was 1000 PNU mL(-1). There was a significant difference in intradermal test reactivity between the atopic groups. At this dilution, 93% (14/15) of the atopic MD group, 31% (5/16) of the atopic group without MD or MO, and 100% (3/3) of the atopic MO only group reacted. There were no significant differences in the serum IgE levels as measured by the Greer ELISA assay, between any groups using any of the three extracts. These results support that Greer's M. pachydermatis extract is useful for intradermal testing of dogs with an allergic phenotype, and that atopics with MD are more likely to have a type-1 Malassezia hypersensitivity than those without. The ELISA assay may require further development in order to be useful for the diagnosis of Malassezia hypersensitivity.

Rapid Effects of Antihistamines on Histamine-Induced Intradermal Reaction Tests by Iontophoresis Method

Rapid Effects of Antihistamines on Histamine-Induced Intradermal Reaction Tests by Iontophoresis Method

Prevalencia de infección tuberculosa en las personas inmigrantes del área de salud de Toledo

The rise in the frequency of tuberculosis is due to several factors: resistance to treatment, human immunodeficiency virus infection, unemployment, poverty and migratory movements. This study is aimed at ascertaining the prevalence of tuberculosis infection among the immigrant population in the Toledo Health District. Descriptive, cross-sectional, multi-center study conducted at the Primary Care level. The immigrants were attracted and recruited on the based of their health cards within the December 2002-September 2003 period. Mantoux intradermal reaction test was performed with 0.1 ml (2UT) of PPD RT-23, following informed consent. Other variables were collected: age, sex, weight, country of origin, work situation, BCG vaccination, number of individuals living with them, length of time residing in Europe. A total of 344 immigrants were included in the study, averaging 28.8 +/- 12.7 years of age. Fifty percent were females (172). They had been living in Europe for an average of 3.4 +/- 3.7 years. A total 78.8% (271) of the immigrants completed the study. The intradermal reaction was positive in 75 of them [27.7% (CI 95%: 23-32.5)]. Those immigrants showing a positive Mantoux were older (age 32.5 +/- 8.5 years) than those showing a negative result (age 27.7 +/- 13.8 years), p=0.006. Originally being from the sub-Saharan area increased the probability of showing a positive intradermal reaction. The immigrant population of the Toledo Health District shows a high prevalence of tuberculosis infection, which is higher than the general Spanish population. Differences exist depending upon the country of origin. These results indicate the importance of considering the Mantoux test among the preventive activities addressed toward this immigrant population.

P‐45 Treatment of allergic feline asthma with allergen avoidance and specific immunotherapy: 20 cats

Twenty cats presented with respiratory signs identified as asthma lasting for several months or years. The episodes of acute coughing and dyspnea were severe, requiring frequent glucocorticoid therapy. An allergic diagnosis was proposed in order to identify the putative allergens involved and to try specific therapy. Three cats developed diabetes mellitus secondary to glucocorticoid treatments. Two of them could not be tested and were given inhalant therapy with bronchodilators and glucocorticoids several times during the day and night. Intradermal tests were performed in 18 cats using 42 aeroallergens. Three tests were negative, even after a second test. Inhalant therapy was prescribed for three cats. Fifteen cats showed positive intradermal test reactions to house dust mites, storage mites and less frequently, pollens. When intradermal test results were positive for storage mites or cockroach, elimination of dried food was first recommended. This was sufficient for remission of the respiratory signs in three cats. Specific immunotherapy was prescribed for the other 12 cats. At the initiation of immunotherapy, all cats were treated with inhaled medications. After 6–9 months, immunotherapy was effective in controlling clinical signs of asthma without any other symptomatic treatment in eight cats. Four cats still required inhaled salbutamol and beclometasone two to three times weekly, instead of two to three times daily. This study demonstrates the role of allergenic stimuli in feline asthma and the advantage of specific immunotherapy as a long‐term treatment. Funding: Self‐funded.

P‐44 The presence of dust mite species in the environment of dust mite‐sensitized atopic dogs

Dust mites (DM), especially Dermatophagoides farinae (DF), are the most common offending aeroallergens in atopic dogs. The aim of this study was to compare the DM species in the households of atopic dogs (Group A, n = 8) that reacted intradermally to DF, D. pteronyssinus (DP), Acarus siro (AS), Lepidoglyphus destructor (LD) and/or Tyrophagus putrescentiae (TP), to DM species in households of nonatopic dogs (Group B, n = 4) and households without pets (Group C, n = 8). Group A dogs exhibited perennial pruritus, were free of pathogenic mites and fleas, did not respond to an elimination diet, and fulfilled the diagnostic criteria for atopic dermatitis. All Group B dogs tested ID negative and had no dermatological problems. Dust samples were vacuum collected in a standardized fashion from two sites of the dog living quarters, one time for each season. DM quantitation was made stereoscopically and their species identification by microscopy. DM median number in Group A was 1.5 for DF, 0.5 for DP and 0 for the other three species. One of eight, one of four and one of four dogs were sensitized to DF, AS and TP, respectively, despite the absence of these species from their environment. No difference could be found in terms of DM species between the three groups (lowest P value = 0.06). In conclusion, cross‐sensitization between DM or irritant intradermal test reactions to their allergenic extracts may be common, and no preferential overpopulation of DF can explain the frequent sensitization of atopic dogs to this mite. Funding: Self‐funded.

FC‐30 Presence of dust mites in the environment of dust mite‐sensitized atopic dogs

Dust mites (DM) are the most common offending aeroallergens in atopic dogs. The aim of this study was to compare the DM load of households with atopic dogs (Group A, n = 8) that had positive intradermal test reactions to Dermatophagoides farinae, D. pteronyssinus, Acarus siro, Lepidoglyphus destructor and/or Tyrophagus putrescentiae to the DM load of households with nonatopic dogs (Group B, n = 4) and of nonpet households (Group C, n = 8). Group A dogs presented with perennial pruritus, were free of pathogenic mites and fleas, did not respond to an elimination diet, and fulfilled the diagnostic criteria of atopic dermatitis. All Group B dogs tested intradermally negative and had no dermatological problems. Dust samples were vacuum collected in a standardized fashion from the human (all groups) and dog mattresses (Groups A and B) or from the couch (Group C) four times, once for each season of the year. The presence of DM was assessed with a commercial test (Acarex test) and stereoscopically. At least one DM was found in all Group A houses. The DM load was not significantly different between the seasons or the three animal groups. The sensitivity of the Acarex test was significantly lower than that of stereoscopic examination (P < 0.001). In conclusion, the environmental DM load was similar between atopic and nonatopic dogs, the presence of dogs in a household didn't increase DM numbers, and stereoscopy was more sensitive than the Acarex test for the detection of DM. Funding: Self‐funded.

Clinical, histopathological and immunological effects of exposure of canine skin toMalasseziapachydermatis

The effects of the daily application for 7 days of suspensions of Malassezia pachydermatis to normal canine skin were evaluated in 10 beagle dogs. Four out of six dogs challenged without occlusion developed transient lesions generally characterized clinically by mild erythema with papules and histologically by mild epidermal hyperplasia and a superficial perivascular dermatitis. Saline-treated control sites showed no clinical signs. In four dogs challenged with occlusion, skin lesions occurred at both yeast and saline-treated sites; erythema and papules were more severe at the yeast-treated sites in three dogs. Occlusion induced more persistent lesions, which resolved within 24 days. Population densities of the yeast were highest at day 8 and declined rapidly following cessation of application. Peripheral blood mononuclear cell proliferation indices following M. pachydermatis exposure in vitro and serum concentrations of M. pachydermatis-specific IgG antibodies did not vary significantly during the study. Delayed (24 h) intradermal test reactivity to M. pachydermatis antigens developed in all eight dogs with clinical signs following yeast exposure. This study suggests that the resistance of healthy canine skin to infection by M. pachydermatis is mediated by local delayed hypersensitivity responses and, or innate epidermal immune mechanisms.

Pilot study to assess the effects of early flea exposure on the development of flea hypersensitivity in cats

This pilot study was to determine if early oral flea exposure reduces the incidence of flea allergy dermatitis (FAD) in cats. Eighteen kittens, assigned to three groups, received no flea exposure, oral flea exposure or flea infestation for 12 weeks. Then all the kittens were exposed continually to fleas for 31 weeks. Sensitization was monitored using intradermal testing (IDT), in vitro measurement of anti-flea saliva immunoglobulin E (IgE) and development of FAD. There was no statistically significant difference between groups in IDT reactions, in vitro data or clinical scores. The development of FAD was not associated with the presence of anti-flea saliva IgE. However, the development of a delayed reaction to flea bite was associated with symptoms after flea exposure. Although not statistically significant, the FAD scores in the oral group were lower than in the controls. Further studies are required to determine the role of oral flea exposure in the development of FAD in cats.

The prevalence of immediate and delayed type hypersensitivity reactions to Microsporum canis antigens in cats

Spontaneous recovery from Microsporum canis infections in cats is thought to be dependent on the development of a competent immune response. The purpose of this study was to determine the prevalence of positive delayed type hypersensitivity reactions in cats with and without dermatophytosis. Four groups of cats were intradermally skin tested with M canis extract and test sites were evaluated both subjectively and objectively at 0, 24 and 48 h after injection. Delayed intradermal testing (IDT) reactions were absent in cats not exposed to dermatophytosis ( n=20); infected–recovered cats ( n=38 culture negative lesion negative and n=43 lesion negative but culture positive) had significantly larger IDT reactions than unexposed cats and cats that were still actively infected ( n=18). Based on the results of this study, IDT with M canis extract can be used to assess the cellular immune response of cats with dermatophytosis.

Tuberculose bovine au Mali : résultats d’une enquête épidémiologique dans les élevages laitiers de la zone périurbaine du district de Bamako

L’enquête a été réalisée dans 36 troupeaux bovins laitiers repartis dans 19 sites localisés dans la zone périurbaine du district de Bamako. Au total 1 087 sujets ont subi le test d’intradermoréaction comparative avec 202 (18,58 p. 100) cas de réaction positive. La prévalence au sein des troupeaux a été évaluée à 94,44 p. 100 (34 troupeaux positifs au test d’intradermoréaction sur 36 testés). Les résultats ont montré que, dans les troupeaux visités, la prévalence intradermo comparative individuelle positive a varié selon l’âge et la race des animaux testés : elle a été plus élevée chez les adultes âgés de plus de 10 ans (44,18 p. 100) et les sujets appartenant aux races bovines importées et ceux issus de croisement (22,42 p. 100).

Caprine tuberculosis eradication program: an immunohistochemical study

We studied the evolution of different forms of tuberculosis in herds which are periodically submitted to the comparative tuberculin intradermal reaction (CTID) test within the Caprine Tuberculosis Eradication Program in the Region of Murcia (Spain). In the study, 135 goats with tuberculosis from different herds were diagnosed by histopathological and immunocytochemical techniques. Most animals (58 of the 135) were in the primary complex of tuberculosis, with few or no acid-fast bacilli (AFB) and mycobacterial antigens. Generalized tuberculosis was present in 31 of the 135 animals, and the numbers of bacilli and positive immunocytochemical particles were higher than in animals with the primary complex. Postprimary phase was observed in 44 of the 135 animals, and the number of bacilli and positive immunocytochemical particles increased in proportion to the extent and gravity of the necrotic foci. Tuberculous pneumonia with a high number of bacilli was only observed in two goats. Extrapulmonary tuberculosis was present with lesions in the intestines (60/135), liver (80/135) and spleen (77/135). This study confirmed that the Caprine Tuberculosis Eradication Program is resulting in fewer animals with postprimary tuberculous processes, and a corresponding increase in the number of primary complex and generalized tuberculosis.

Evaluation of the usefulness of sensitization to aeroallergens as a model for canine atopic dermatitis in genetically predisposed Beagles.

To evaluate a model for atopic dermatitis (AD) and to measure the effect of sensitization in Beagles genetically predisposed to produce high serum concentrations of allergen specific IgE. 22 laboratory Beagles. Seventeen dogs were sensitized from birth to 3 allergens (recombinant birch pollen, Dermatophagoides pteronyssinus, and D farinae). Five nonsensitized dogs from the same litters served as controls. Clinical scoring, regular intradermal testing, measurement of serum concentrations of allergen-specific IgE, and collection of biopsy specimens of skin at 23, 32, and 43 weeks of age were performed. Serial tissue sections were stained for identification of IgE+ cells, mast cells and their subtypes, T-cells, Langerhans cells, and major histocompatibility complex class-II+ cells. At the age of 15 months, dogs were continuously exposed to 2 microg of mite allergen/g of dust. Sensitized dogs had positive intradermal test reactions and significantly higher serum concentrations of allergen specific IgE, compared with nonsensitized dogs. In sensitized and nonsensitized dogs, a significantly higher number of mast cells was found at predilection sites, compared with the control biopsy site. The number of mast cells at predilection sites increased with age. Sensitization significantly increased the number of epidermal Langerhans cells by 23 weeks of age. The number of epidermal Langerhans cells significantly increased in nonsensitized dogs by 32 weeks of age. Clinical scoring only revealed mild transient erythema in some dogs. increases in concentrations of serum allergen-specific IgE and exposure to allergens is not sufficient to induce clinical signs of AD in genetically predisposed dogs.

A pilot trial on the effect of Cyclosporin A on intradermal skin test reactions in dogs with atopic dermatitis

The purpose of this study was to determine if Cyclosporin A, given at a dose of 5 mg kg−1 per day for 42 days, negatively influenced intradermal skin test results in dogs with atopic dermatitis. Six mixed‐breed dogs of varying ages and sexes with a clinical diagnosis of atopic dermatitis were included in this study. All dogs were intradermally skin tested (IDT) with 61 allergens from varying groups, grass pollens, weed pollens, tree pollens, moulds, insects and dust mites. IDT reactions were recorded as absent, weak, moderate or strong reactions. All dogs showed several strong reactions in the initial IDT. On days 0 to 42, the dogs received 5 mg kg −1 per day of Cyclosporin A. On day 42, all dogs showed a marked reduction in pruritus. A second IDT was performed and the results of both tests compared. The χ2‐test was used to statistically analyse changes between pre‐ and post‐treatment reactions for each of the allergen groups. There were no mould reactions recorded and this group was discarded from analysis. When all reactions were used in analysis, Cyclosporin A tended to significantly reduce the number of IDT reactions. However, when only moderate and strong reactions were considered (weak reactions excluded) there were no significant differences between pre‐ and post‐treatment results for the other allergen groups. Cyclosporin A at a dose of 5 mg kg−1 per day for 42 days controlled pruritus, but did not significantly alter moderate and strong intradermal skin test reactions in the six dogs tested. This suggests that Cyclosporin A, at this dose, did not prevent mast cell degranulation. Funded by Novartis Animal Health, Australia.

Immediate intradermal flea‐antigen reactivity in dogs in a flea‐scarce environment

The aim of this study was to determine the prevalence of intradermal test (IDT) reactions to flea antigen in dogs in a flea‐scarce environment. Seventy‐three client‐owned dogs without present or prior exposure to fleas were used. Forty dogs had a history of, and clinical signs compatible with, atopic dermatitis (AD), after exclusion of other causes of pruritus, and 33 dogs were healthy or had some disease other than AD. A questionnaire was used to collect information about previous ectoparasitic infestations. An aqueous extract of whole bodies of Ctenocephalides spp. (Nelco Laboratories Inc., NY, USA) was used for IDT at a concentration of 1:1000 w/v. None of the dogs had been treated with corticosteroids or antihistamines within the previous 3 months. A positive reaction was defined as a wheal that was equal to or larger in diameter than the average of the saline and histamine controls. Two of the dogs with clinically diagnosed AD and none of the nonatopic dogs had immediate skin‐test reactions to flea antigen. The prevalence (2.7%) for positive IDT against flea extract found in this study is low compared with studies performed in a flea‐rich environment. Immediate skin‐test reactivity against flea antigen in clinically normal dogs in flea‐endemic areas could represent subclinical hypersensitivity or true false‐positive reactions (due to skin irritation). Thus, these findings indicate that false‐positive reactions against whole‐body flea antigen from Nelco in dogs not exposed to fleas are rare.

Allergen‐specific immunotherapy in dogs with atopic dermatitis and house dust mite hypersensitivity: use of symptom/medication scores

There is no published literature on the efficacy of allergen‐specific immunotherapy (ASIT) for dogs with atopic dermatitis (AD) and house dust mite (HDM) hypersensitivity. Symptom/medication (SM) scoring is the standard measure of clinical disease during ASIT in humans. The purpose of this study was to determine the response to ASIT in dogs with AD and HDM hypersensitivity using SM scores, and compare results with the owner’s global assessment and the investigator’s clinical evaluation. All dogs had nonseasonal AD, positive intradermal test reactions to HDM, and were treated for 12 months with ASIT that included HDM allergens. Evaluations at 0, 3, 6, 9 and 12 months included: daily owner symptom (pruritus, lesions, coat character) and medication (all anti‐inflammatory medications) scoring for 28 days; owner global assessment; and investigator clinical sign score. Occurrence of skin infections was documented throughout the study. Statistical analysis of SM scores at 0 and 12 months was performed using Student’s t‐test. Nineteen dogs completed the study. Fourteen (74%) dogs showed significant improvement (P < 0.05) in SM score. A 50% improvement in SM score, owners’ global assessment and clinical sign score was seen in 12 (63%), 17 (89%) and 10 (53%) dogs, respectively. In the first 6 months of ASIT, 17 episodes of skin infections (12 dogs) were recorded, and 13 episodes (10 dogs) in the final 6 months. The majority of dogs with AD and HDM hypersensitivity improved with ASIT. SM scores are a useful semiquantitative measure of clinical disease. Many dogs continued to have skin infections. This study was funded by the Ohio Animal Health Foundation.

Serological responses to house dust mite antigens in atopic dogs while receiving allergen‐specific immunotherapy

In human atopic disease a beneficial response to immunotherapy may be associated with humeral changes in serum IgE and subclass IgG. The aim of this study was to investigate the humeral response to allergen‐specific immunotherapy (ASIT) in dogs with atopic dermatitis. Twelve dogs with clinical signs consistent with atopic dermatitis and positive intradermal test reactions to house dust mite antigens (Greer Laboratories, Lenoir NC, USA) were studied. The clinical response to ASIT (Greer) was evaluated when blood samples were collected at 0, 2 and 4 weeks; and at 3, 6 and 12 months after starting ASIT. The ASIT was administered for a minimum of 9 months. The serum concentration of total and subclass IgG antibodies was measured against Dermatophagoides farinae and Dermatophagoides pteronyssinus antigens (Greer) by ELISA using polyclonal and monoclonal antidog IgG reagents, respectively. Serum IgE was measured using a Fc‐epsilon R1 receptor alpha chain‐based ELISA. The data were analysed using a multilevel model in MLwiN software (Institute of Education, University of London, UK). Antibody concentrations of IgE and total IgG increased during the period of administration of ASIT and decreased after ASIT was stopped. There was no obvious pattern in subclass‐IgG concentrations during ASIT. Response to ASIT was excellent (four dogs), equivocal (three dogs) or poor (five dogs). During ASIT a poor or equivocal response was associated with a statistically significant increase in IgE to D. pteronyssinus antigen compared with the excellent responders. This relationship was present to a lesser extent with IgE to D. farinae and total IgG to both antigens. This study was supported, in part, by the RCVS Alison Alston Canine Award and by Heska Corporation.

Intradermal test reactivity to Malassezia pachydermatis in healthy basset hounds and basset hounds with Malassezia dermatitis

Nineteen healthy beagles, eight healthy basset hounds and 17 basset hounds with Malassezia dermatitis weretested intradermally with two extracts of M pachydermatis. One healthy beagle and two affected basset houndsshowed...

Insulin-induced Drug Eruptions and Reliability of Skin Tests

Allergic reaction to insulin preparations seemed to have decreased since the introduction of contaminant-free, human preparations. The role of protamine sulfate in decreasing the prevalence of allergy is unclear. This study examines the causative components of insulin allergy along with the value of skin tests for diagnosis. Eleven patients with insulin allergy and 53 patients receiving insulin but without an insulin allergy were included as controls. Intradermal skin tests were conducted using preparations containing various concentrations of insulin [Neutral protamine Hagedorn (NPH) insulin, regular insulin (RI)] and protamine sulfate. Of the 11 patients studied, 3 had anaphylaxis and 8 displayed localized reactions. All of the patients reacted positively during skin testing. Five patients showed positive intradermal skin test reactions to protamine sulfate, and 4 reacted to insulin. Two patients that were not tested with protamine sulfate reacted positively to NPH insulin. In the case of protamine sulfate, 4 patients with localized symptoms displayed positive reactions at concentrations of 10 microg/ml, 3 microg/ml or 0.3 microg/ml. One patient with anaphylaxis reacted positively to a concentration as low as 0.03 ng/ml. In the case of insulin protein, 3 patients reacted positively to a 100-fold dilution (1 UI/ml). Eight of the 53 controls experienced pruritus and/or skin lesions. However, none of the controls reacted at a concentration of NPH insulin of less than 10 U/ml or to protamine sulfate at less than 30 microg/ml. Allergic reactions to protamine sulfate are common and should not be ignored. This study shows a good correlation between clinical manifestations and skin test reactions for insulin allergy.

Sensitivity patterns to house dust mites and forage mites in atopic dogs: 150 cases.

This study investigated intradermal test reactions to extracts of six species of mites in 150 dogs with atopic dermatitis. At least one positive reaction was seen in 120 animals (80%). Dermatophagoides farinae attracted the highest number of positive reactions (108 dogs, 90% of dogs and 72% of atopic dogs showing positive reactions). Positive reactions to other mites were not uncommon, with many dogs testing positive for Dermatophagoides pteronyssinus (32% of dogs tested), Acarus siro (35%), Tyrophagus putrescentiae (30%), Glycyphagus domesticus (27%) and Lepidoglyphus destructor (23%). Sensitivity to D. farinae alone occurred commonly (57% of cases), but multiple sensitivities were seen frequently with the other mites. Cases of sensitivity to only one mite were also seen: D. pteronyssinus (five cases), T. putrescentiae (one case) and G. domesticus (one case). Further studies are needed to appreciate more clearly the precise role played by the different species of mite in canine atopic dermatitis.

Natural rubber pharmaceutical vial closures release latex allergens that produce skin reactions

Background: The release of allergenic proteins from natural rubber vial closures (stoppers) into aqueous pharmaceuticals may induce allergic reactions in individuals with latex allergy (LA) receiving medications from such vials. Objective: The goal of this study was to determine whether solutions stored in vials containing natural rubber closures release allergenic proteins detectable by skin testing of subjects with LA. Methods: Five pharmaceutical vial closures (2 natural rubber and 3 synthetic) were coded, inserted onto vials containing phenol-saline-human serum albumin, and stored in an inverted position before use. Twelve volunteers with and 11 volunteers without LA underwent skin testing with solutions from each of the 5 vials, either those not punctured (0P) or those punctured 40 times with a 21-gauge needle 12 to 24 hours before testing (40P). Results: All intradermal skin test responses in the group without LA were negative. Two and 5 of the 12 subjects with LA had positive intradermal skin reactions to 0P and 40P solutions, respectively, from vials containing rubber closures. Two subjects with LA had inexplicable, positive, nonreproducible intradermal skin test reactions to solutions from vials containing bromobutyl but not vials with isoprene synthetic closures. In vitro inhibition analysis detected 6 to 7 AU/g latex allergen in extracts of cut natural rubber containing closures but not in extracts of synthetic closures. Conclusion: Natural rubber vial closures released allergenic latex proteins into the tested solutions in direct contact during storage in sufficient quantities to elicit positive intradermal skin reactions in some individuals with LA. These data support a recommendation to eliminate natural rubber from closures of pharmaceutical vials. (J Allergy Clin Immunol 2001;107:958-62.)