EAACI position paper: Comparing insect hypersensitivity induced by bite, sting, inhalation or ingestion in human beings and animals.

Adverse reactions to insects occur in both human and veterinary patients. Systematic comparison may lead to improved recommendations for prevention and treatment in all species. In this position paper, we summarize the current knowledge on insect allergy induced via stings, bites, inhalation or ingestion, and compare reactions in companion animals to those in people. With few exceptions, the situation in human insect allergy is better documented than in animals. We focus on a review of recent literature and give overviews of the epidemiology and clinical signs. We discuss allergen sources and allergenic molecules to the extent described, and aspects of diagnosis, prophylaxis, management and therapy.

Serum IgE against cross-reactive carbohydrate determinants (CCD) in healthy and atopic dogs.

BACKGROUND: Cross-reactive carbohydrate determinants (CCD) are Immunoglobulin E (IgE)-binding carbohydrate structures common to plant and insect species. In people, anti-CCD IgE is thought to be clinically irrelevant, but to have the potential to confound serological IgE test interpretations. Previous studies reported the detection of anti-CCD IgE in 24-73% of atopic dog sera; prevalence in healthy dogs has not been reported. OBJECTIVE: To compare the prevalence of anti-CCD IgE in a group of healthy and atopic dogs. ANIMALS: Sera from 61 healthy dogs and 101 dogs with a clinical diagnosis of atopic dermatitis were analyzed for IgE against CCD. METHODS AND MATERIALS: Sera were analyzed for the presence of anti-CCD IgE and IgE against environmental allergens using a commercial multiplex allergen-specific IgE assay. RESULTS: Anti-CCD IgE was detected in 17 of 101 (16.8%) atopic dog sera and eight of 61 (13.1%) healthy dog sera (P = 0.65, Fisher's exact test). All healthy and atopic dogs with anti-CCD IgE had strong reactivity to grass pollens. CONCLUSIONS AND CLINICAL IMPORTANCE: A similar prevalence of anti-CCD IgE was found in healthy and atopic dogs. Further investigation is warranted to determine the clinical significance of anti-CCD IgE antibodies in dogs, how they are best detected and if blocking these antibodies during diagnostic testing has clinical value.

A preliminary study of serum IgE against cross-reactive carbohydrate determinants (CCD) in client-owned atopic dogs.

BACKGROUND: Cross-reactive carbohydrate determinants (CCD) are defined carbohydrate portions of glycoprotein cell surface molecules common to many plant and insect species. Mammalian species recognize CCD as foreign antigens and can mount humoral immune responses against them. Approximately 20-37% of grass and venom allergic people possess circulating IgE against CCD; these antibodies are generally considered clinically irrelevant. Anti-CCD IgE is, however, recognized as a cause of false positive, clinically incongruent serum allergen test results in people; this phenomenon has not been investigated in animals. OBJECTIVE: To determine if anti-CCD IgE could be detected in sera of client-owned atopic dogs and how frequently it is found. ANIMALS: Sera from 38 dogs with a clinical diagnosis of atopic dermatitis and prior serological evidence of IgE antibodies, defined as a positive result to at least one mite and pollen (of any type). METHODS: Sera were analysed for IgE against CCD and environmental allergens with a commercially available multiplex enzyme-labelled allergen-specific IgE assay. RESULTS: Anti-CCD IgE was detected in nine of 38 (24%) of atopic dog sera. As with their human counterparts, all dogs with anti-CCD IgE had strong serological reactivity to grass pollens. CONCLUSIONS AND CLINICAL IMPORTANCE: Anti-CCD IgE can confound serological allergen testing in people; the same might be true in dogs. Further studies are warranted to investigate the clinical implications of anti-CCD IgE in dogs, including the potential for these antibodies to affect serum allergen-specific IgE assays used for clinical diagnosis, and whether they are relevant to clinical disease.

The future of immunotherapy for canine atopic dermatitis: a review.

Allergen specific immunotherapy (ASIT) is a foundation treatment for canine atopic dermatitis (CAD), though few critical studies have documented its effectiveness as a disease-modifying treatment in dogs. The mechanisms by which ASIT works in dogs have not been elucidated, although they are likely to parallel those known for humans. Current ASIT approaches in CAD focus on either subcutaneous or sublingual administration. Greater knowledge of major allergens in dogs, ideal dosage regimes and details of allergen admixture are likely to lead to better efficacy in CAD. Evaluation of biomarkers for successful therapy may also be of benefit. Potentially important advances in human medicine, that have yet to be explored in dogs, include use of modified allergen preparations such as allergoids, recombinant major allergens or allergen peptides; modification with adjuvants; or packaging of the above in virus-like particles. Co-administration of immunomodulators such as CpG oligodeoxynucleotides or specific monoclonal antibodies might direct the immune response in the desired direction while calming the "cytokine storm" of active disease. Initial trials of alternative routes of administration such as intralymphatic immunotherapy have yielded exciting results in humans, and continuing study in dogs is underway. Progress in ASIT of human food allergy may provide clues that will assist with improved diagnosis and patient management of CAD. Importantly, further study must be undertaken to clarify the conditions under which ASIT is a valuable treatment modality for dogs.

Clinical and immunological responses of dust mite sensitive, atopic dogs to treatment with sublingual immunotherapy (SLIT).

BACKGROUND: Sublingual immunotherapy (SLIT) has been reported to be beneficial in people with atopic dermatitis (AD) and dust mite sensitivity. Evaluation of this therapy has not been reported in spontaneous canine AD. OBJECTIVES: The objective of this study was to preliminarily evaluate the effectiveness of an established SLIT protocol, as used in human patients, in dogs with AD. ANIMALS: Ten dust mite sensitive dogs with spontaneous AD. METHODS: Dogs underwent a 6 month open trial of SLIT concurrently with decreasing dose oral methylprednisolone. Clinical evaluations and quantitative serum anti-mite IgE and IgG levels were performed every 2 months. RESULTS: Mean methylprednisolone use from the first 2 months of the study to the final 2 months declined from 10.2 to 4.3 mg/kg/2 months (P < 0.001, Student's paired t-test); at 6 months, four dogs required no oral corticosteroid administration. Over the course of the study, median Canine Atopic Dermatitis Extent and Severity Index (CADESI)-03 scores declined from 76.5 to 59; median pruritus scores declined from 65 to 37 (P < 0.02 and P < 0.01, respectively; Wilcoxon signed-rank test). Pre- and post-SLIT intradermal test scores for mite allergen were not significantly different over time. Median Dermatophagoides farinae (DF)-specific IgE levels declined significantly from 150.2 × 10(3) AU/mL to 3.6 × 10(3) AU/mL (P < 0.05). Concurrently, median DF-specific IgG levels increased from 18.5 × 10(6) AU/mL to 3923.4 × 10(6) AU/mL (P < 0.05; Wilcoxon signed-rank tests). CONCLUSIONS AND CLINICAL IMPORTANCE: SLIT treatment produced clinical improvement in dogs with dust mite-associated AD and was associated with serological changes supporting this improvement. Further studies in larger numbers of dogs and those with polysensitization are warranted.

Treatment of canine atopic dermatitis: 2015 updated guidelines from the International Committee on Allergic Diseases of Animals (ICADA).

BACKGROUND: In 2010, the International Task Force on Canine Atopic Dermatitis (now International Committee on Allergic Diseases of Animals, ICADA) published the first consensus guidelines for the treatment of atopic dermatitis (AD) in dogs. This is the first 5-year minor update of this document. RESULTS: The treatment of acute flares of AD should involve the search for, and then elimination of, the cause of the flares, bathing with mild shampoos, and controlling pruritus and skin lesions with interventions that include topical and/or oral glucocorticoids or oclacitinib. For chronic canine AD, the first steps in management are the identification and avoidance of flare factors, as well as ensuring that there is adequate skin and coat hygiene and care; this might include more frequent bathing and possibly increasing essential fatty acid intake. The medications currently most effective in reducing chronic pruritus and skin lesions are topical and oral glucocorticoids, oral ciclosporin, oral oclacitinib, and, where available, injectable recombinant interferons. Allergen-specific immunotherapy and proactive intermittent topical glucocorticoid applications are the only interventions likely to prevent or delay the recurrence of flares of AD. CONCLUSIONS: This first 5-year minor update of the international consensus guidelines for treatment of AD in dogs further establishes that the treatment of this disease is multifaceted, and that interventions should be combined for a proven (or likely) optimal benefit. Importantly, treatment plans are likely to vary between dogs and, for the same dog, between times when the disease is at different stages.

Comparison of the results of intradermal test reactivity and serum allergen-specific IgE measurement for Malassezia pachydermatis in atopic dogs.

BACKGROUND: Malassezia pachydermatis is part of the normal flora of canine skin. Malassezia hypersensitivity is recognized as a trigger for clinical signs of atopic dermatitis (AD) in some dogs. Determinations of Malassezia hypersensitivity are often made with intradermal testing (IDT), which may have limited availability in a first-opinion veterinary practice. HYPOTHESIS/OBJECTIVES: The purpose of this study was to compare immediate IDT reactivity to M. pachydermatis with results of an enzyme-linked immunosorbent assay (ELISA) designed to detect anti-Malassezia IgE. ANIMALS: Eighty-four dogs with a clinical diagnosis of AD. METHODS: Multi-allergen IDT was performed on all dogs. Serum testing for allergen-specific IgE against a panel of common environmental allergens and M. pachydermatis was performed by ELISA using the FcεRIα receptor fragment as a detection reagent, with results reported as adjusted optical density (OD). A receiver operating characteristic (ROC) curve was used to analyse the results of the two tests. RESULTS: The median adjusted OD of the anti-Malassezia IgE ELISA for dogs reactive and nonreactive to M. pachydermatis on IDT was 0.137 and 0.024, respectively. Analysis of the ROC curve suggested a cut-off point for the anti-Malassezia ELISA that yielded a sensitivity of 77.0% and a specificity of 89% relative to IDT results. CONCLUSIONS AND CLINICAL IMPORTANCE: Substantial agreement was demonstrated between IDT reactivity and anti-Malassezia IgE as detected by the FcεRIα receptor reagent. Although correlation with a clinical diagnosis of Malassezia dermatitis was not attempted in this study, the results indicate that the ELISA may be used to demonstrate the presence of immediate-type Malassezia hypersensitivity in dogs with AD.

Serum allergen-specific immunoglobulin E in atopic and healthy cats: comparison of a rapid screening immunoassay and complete-panel analysis.

Feline and canine atopic dermatitis are thought to have a similar immunopathogenesis. As with dogs, detection of allergen-specific IgE in cat serum merely supports a diagnosis of feline atopy based on compatible history, clinical signs and elimination of other pruritic dermatoses. In this study, a rapid screening immunoassay (Allercept(®) E-Screen 2nd Generation; Heska AG, Fribourg, Switzerland; ES2G) was compared with a complete-panel serum allergen-specific IgE assay (Allercept(®); Heska AG; CP) in healthy cats with no history of skin disease and in atopic cats. The latter had no diagnosis of external parasitism, infection, food hypersensitivity or other skin disease explaining their pruritus, and expressed cutaneous reaction patterns typically associated with feline allergic skin disease (head, neck or pinnal pruritus, miliary dermatitis, self-induced alopecia, eosinophilic granuloma complex). The proportion of cats positive on either the ES2G or the CP assays was not significantly different between the atopic and healthy cat groups. There was, however, strong agreement between the results of the ES2G and CP assay; overall, the two tests were in agreement for 43 of 49 (88%) serum samples. There was also strong agreement when individual allergen groups were evaluated (agreement noted: indoor, 41 of 49 samples; grasses/weeds, 37 of 49 samples; and trees, 41 of 49 samples). These results indicate that although neither test is diagnostic for feline atopic dermatitis, the screening assay is beneficial for predicting the results of a complete-panel serum allergen-specific IgE assay in cats.

Treatment of canine atopic dermatitis: 2010 clinical practice guidelines from the International Task Force on Canine Atopic Dermatitis.

Atopic dermatitis (AD) is a common chronic relapsing pruritic skin disease of dogs for which treatment has varied over time and geographical location. Recent high quality randomized controlled trials and systematic reviews have established which drugs are likely to offer consistent benefit. The International Task Force for Canine AD currently recommends a multi-faceted approach to treat dogs with AD. Acute flares should be treated with a combination of nonirritating baths and topical glucocorticoids, once an attempt has been made to identify and remove the suspected causes of the flare. Oral glucocorticoids and antimicrobial therapy must be added when needed. In dogs with chronic AD, a combination of interventions should be considered. Again, factors that trigger flares of AD must be identified and, if possible, avoided. Currently recognized flare factors include food, flea and environmental allergens, Staphylococcus bacteria and Malassezia yeast. Skin and coat hygiene and care must be improved by bathing with nonirritating shampoos and dietary supplementation with essential fatty acids. The severity of pruritus and skin lesions can be reduced with a combination of anti-inflammatory drugs. Currently, medications with good evidence of high efficacy include topical and oral glucocorticoids, and calcineurin inhibitors such as oral ciclosporin and topical tacrolimus. The dose and frequency of administration of these drugs should be tailored to each patient considering each drug's efficacy, adverse effects and cost. Allergen-specific immunotherapy should be offered, whenever feasible, in an attempt to prevent recurrence of clinical signs upon further exposure to environmental allergens to which the patient is hypersensitive.

IgE sensitivity to Malassezia pachydermatis and mite allergens in dogs with atopic dermatitis.

In this study, dogs with atopic dermatitis were separated into non-food-induced atopic dermatitis (NFIAD) group (n = 15) and food-induced atopic dermatitis (FIAD) group (n = 37) based on an elimination diet test. IgE reactivity for crude Malassezia pachydermatis (M. pachydermatis) and house dust mites (HDM) allergen extracts was investigated in the two groups using fluorometric enzyme-linked immunosorbent assay (ELISA) and intradermal skin test (IDST). Nine (60%) of the 15 dogs in NFIAD group and 6 (16%) of the 37 dogs in FIAD group showed specific IgE for M. pachydermatis (Mann-Whitney U-test, P < 0.01). By immunoblotting analysis, the pooled serum samples from dogs with IgE for M. pachydermatis showed IgE reactivity for 50 kDa protein of M. pachydermatis. Twelve (80%) of the 15 dogs in NFIAD group and 8 (22%) of the 37 dogs in FIAD group showed specific IgE for HDM (Mann-Whitney U-test, P < 0.01). In addition, the dogs in NFIAD group significantly show a positive IDST to M. pachydermatis and HDM extracts compared with the dogs in FIAD group. The results suggest that dogs with NFIAD are at increased risk of becoming sensitized to the normal commensal organism M. pachydermatis compared with dogs with FIAD, perhaps co-sensitization occurred due to an HDM protease antigen's, Der f 1 and/or Der p 1, proteolytic activity related epidermal skin barrier defects. Treatment to limit skin colonization may thus be especially important in NFIAD.

Formulations for Allergen Immunotherapy in Human and Veterinary Patients: New Candidates on the Horizon.

Allergen immunotherapy is currently the only causal treatment for allergic diseases in human beings and animals. It aims to re-direct the immune system into a tolerogenic or desensitized state. Requirements include clinical efficacy, safety, and schedules optimizing patient or owner compliance. To achieve these goals, specific allergens can be formulated with adjuvants that prolong tissue deposition and support uptake by antigen presenting cells, and/or provide a beneficial immunomodulatory action. Here, we depict adjuvant formulations being investigated for human and veterinary allergen immunotherapy.

Performance characteristics of a monoclonal antibody cocktail-based ELISA for detection of allergen-specific IgE in dogs and comparison with a high affinity IgE receptor-based ELISA.

The purpose of this study was to define the operational and performance characteristics of a commercially available monoclonal antibody based (mac) ELISA for detection of allergen-specific IgE in dogs. The average intra-assay variance over 1 year was 9.7% (range 2.5-62.7%), while the interassay variance averaged 10.8% (range 8.1-13.8%). The average positive control responses observed for grass, weed, tree and mite allergens during each month remained relatively constant; the average monthly variance was 11.6% (range 8.3-19.2%) for grass pollens, 13.3% (range 9.1-20.4%) for weed pollens, 13.3% (range 9.8-18.2%) for tree pollens and 13.6% (range 8.9-18.7%) for mite allergens. The interlaboratory concordance of results for the macELISA was approximately 91%. The interlaboratory concordance of results comparing the macELISA and a high affinity IgE receptor-based ELISA was approximately 92%. The results demonstrate that the macELISA is reproducible and the results are comparable to the high affinity IgE receptor based ELISA within and between laboratories.

Immunoblot analysis for IgE-reactive components of fetal calf serum in dogs that developed allergic reactions after non-rabies vaccination.

We previously demonstrated the presence of IgE directed to fetal calf serum (FCS) in the sera from dogs that developed allergic reactions after vaccination. In this study, by an immunoblot analysis, we investigated the IgE-reactive components of FCS using sera from 16 dogs that exhibited allergic reactions after vaccination. The immunoblot analysis revealed that several FCS proteins of approximately 25-, 50-, 66-, 75-, 120-, and 175-kDa strongly reacted with IgE in the sera from dogs that showed post-vaccination allergic reactions. The 66-kDa band was detected in the sera from 14 of the 16 dog serum samples analyzed in the immunoblot analysis for FCS, and it was speculated to be albumin based on its molecular weight; however, serum IgE reactivity to bovine serum albumin could be detected in only four of the 14 dog samples. These findings demonstrated that a variety of FCS components including albumin could function as allergens in dogs that developed allergic reactions after vaccination.

Serum Malassezia-specific IgE in dogs with recurrent Malassezia otitis externa without concurrent skin disease.

Immediate-type hypersensitivity (ITH), mediated by IgE, to Malassezia pachydermatis is recognized in atopic dogs with recurrent yeast dermatitis and otitis externa (OE). Malassezia-associated OE commonly occurs in dogs without other signs of atopic dermatitis (AD). The aim of this study was to detect Malassezia-specific IgE in the sera of dogs with recurrent Malassezia OE without concurrent skin disease. Sera from healthy dogs were used for comparison. An FcεRIα-based ELISA was used to measure Malassezia-specific IgE. There was no significant difference between number of positive affected dogs (6/21, 29%) and number of positive unaffected dogs (15/86, 17%) (P=0.36). There was also no significant difference in the concentrations of Malassezia-specific IgE between the two groups (P=0.97). Malassezia-specific IgE did not distinguish between patient groups so, as with other canine allergens, serum IgE reactivity for Malassezia could not be used to differentiate between diseased and healthy patients. The presence of Malassezia-specific IgE in some of the affected dogs might indicate ITH to Malassezia in those dogs. Evaluation of ITH via intradermal test reactivity and response to allergen-specific immunotherapy might clarify the role of Malassezia-associated ITH in similarly affected dogs.

IgE reactivity to hen egg white allergens in dogs with cutaneous adverse food reactions.

Dogs with cutaneous adverse food reactions (CAFR) often have specific IgE to food allergens. Egg white, which is majorly composed of ovomucoid, ovalbumin, ovotransferrin, and lysozyme, is a food allergen in dogs. Information of the IgE reactivity to purified egg white allergens supports accurate diagnosis and efficiency treatment in humans. However, to the best of our knowledge, there have been no studies on the IgE reactivity to purified egg white allergens in dogs. Here, we investigated the IgE reactivity to crude and purified allergens of hen egg white in dogs with CAFR. First, when we examined serum samples from 82 dogs with CAFR for specific IgE to crude egg white by ELISA, 9.8% (8/82) of the dogs with CAFR showed the IgE reactivity to crude egg white. We then used sera from the eight dogs with positive IgE reactivity to crude egg white to examine the IgE reactivity to four purified allergens, ovomucoid, ovalbumin, ovotransferrin, and lysozyme, by ELISA. We found that 75% (6/8) of the dogs showed IgE reactivity to both ovomucoid and ovalbumin, and that 37.5% (3/8) of the dogs showed IgE reactivity to ovotransferrin. None (0/8) showed IgE reactivity to lysozyme. Moreover, validating these results, the immunoblot analyses were performed using the sera of the three dogs showing the highest IgE reactivity to crude egg white. Both anti-ovomucoid and anti-ovalbumin IgE were detected in the sera of these dogs, while anti-ovotransferrin IgE was not detected. Considering these, ovomucoid and ovalbumin appears to be the major egg white allergens in dogs with CAFR.

Molecular characterization of Staphylococcus intermedius carriage by healthy dogs and comparison of antimicrobial susceptibility patterns to isolates from dogs with pyoderma.

We conducted an epidemiological study of Staphylococcus intermedius using arbitrarily primed PCR (AP-PCR) and antibiograms. One hundred and twenty-five S. intermedius isolates were recovered from the oral cavity and/or cranial hair coat of healthy dogs enrolled in a pet therapy program. Commensal S. intermedius was cultured from 32% of the oral cavity cultures and 13% of the cranial hair coat cultures. We characterized the colonization of the dogs as transient, intermittent, or persistent. For dogs characterized as persistently colonized, 73% of the isolates came from the oral cavity. These isolates were also genotyped by AP-PCR. A single major AP-PCR type was observed in 91% of the dogs (n=22); minor variations were frequently observed in these major types. Antibiograms of these commensal isolates were compared to antibiograms from 97 historical clinical isolates (1988-1992) obtained from cases of canine pyoderma. Resistance was most often observed to penicillin (64% and 55%) and tetracycline (38% and 38%) among the commensal and clinical isolates, respectively. The commensal isolates were significantly less resistant to erythromycin, clarithromycin, clindamycin, and trimethoprim/sulfamethoxazole. Our data suggests that differences in both genotype and antimicrobial susceptibility phenotypes exist among S. intermedius strains isolated from different anatomic sites from the same dog and supports the opportunistic nature of S. intermedius in canine infections.

IgE reactivity to vaccine components in dogs that developed immediate-type allergic reactions after vaccination.

Allergic reactions after vaccination are considered as an important practical problem in dogs; however, their immunological mechanism has not been well understood. The present study was designed to investigate the relationship between IgE reactivity to the vaccines and immediate-type allergic reactions after vaccination in dogs. Sera from 10 dogs that developed immediate-type allergic reactions such as circulatory collapse, cyanosis, dyspnea, facial edema, and vomiting within 1h after vaccination with non-rabies monovalent or combined vaccines and sera from 50 dogs that did not develop allergic reactions after vaccination were collected. Serum IgE reactivity to the injected vaccines was measured by fluorometric ELISA using a mouse monoclonal anti-dog IgE antibody. Then, IgE reactivity to fetal calf serum (FCS) and stabilizer proteins (gelatin, casein, and peptone) included in the vaccines was measured in sera that had high levels of IgE to the vaccines. Levels of serum specific IgE to the vaccines in dogs with immediate-type allergic reactions (59-4173 fluorescence units [FU], mean +/- S.D.: 992.5 +/- 1181.9 FU) were significantly higher than those in control dogs (38-192 FU, 92.4 +/- 43.3 FU) (P < 0.001). Of the eight dogs that developed immediate-type allergic reactions and had high levels of serum specific IgE to the vaccines, seven had specific IgE directed to FCS. The IgE reactivity to the vaccines in sera from these dogs was almost completely inhibited by FCS. The other one dog had serum IgE directed to gelatin and casein included in the vaccine as stabilizers. The results obtained in this study suggest that immediate-type allergic reactions after vaccination in dogs were induced by type I hypersensitivity mediated by IgE directed to vaccine components. In addition, FCS, gelatin, and casein included in vaccines could be the causative allergens that induced immediate-type allergic reactions after vaccination in dogs.

Evaluation of serum obtained from atopic dogs with dermatitis attributable to Malassezia pachydermatis for passive transfer of immediate hypersensitivity to that organism.

OBJECTIVE: To determine the functionality of canine anti-Malassezia IgE via the passive transfer of immediate hypersensitivity localized to the skin (ie, cutaneous anaphylaxis) from atopic dogs with dermatitis attributable to overgrowth of Malassezia pachydermatis (Malassezia dermatitis [MD]) to healthy recipient dogs by use of the Prausnitz-Küstner (P-K) technique. ANIMALS: 7 clinically normal dogs, 32 atopic dogs with MD, serum from 11 atopic dogs with MD, and 3 healthy dogs without prior sensitization to M pachydermatis. PROCEDURE: Serum from atopic dogs with MD was used for P-K tests in 3 clinically normal recipient dogs. Serial dilutions of untreated, heat-inactivated, IgE-absorbed, and bovine serum albumin (BSA)-absorbed (control) aliquots of serum were injected ID in triplicate for dermal sensitization. Twenty-four, 48, and 72 hours later, a crude extract of M pachydermatis was injected ID into the sites used for sensitization injections, and immediate hypersensitivity reactions were graded on a 4-point scale. RESULTS: Untreated serum caused P-K reactivity beginning 24 hours after passive sensitization and persisting through 72 hours (titers, 1:32 to 1:64). Heat inactivation and IgE-absorption of serum eliminated P-K reactivity, whereas treatment of serum with BSA did not. CONCLUSIONS AND CLINICAL RELEVANCE: Analysis of P-K test results supports the passive transfer of cutaneous anaphylaxis by anti-Malassezia IgE and indicates it is functional in type-1 hypersensitivity reactions of atopic dogs with MD. Reduction or blockade of anti-Malassezia IgE in atopic dogs with MD may provide better clinical control of the disease.

Safety and immunologic effects after inoculation of inactivated and combined live-inactivated dermatophytosis vaccines in cats.

OBJECTIVE: To determine antidermatophyte immunologic effects of an experimental combined live-inactivated dermatophytosis vaccine (CLIDV) and a commercial inactivated dermatophytosis vaccine (IDV) in cats and to evaluate adverse effects associated with administration of these vaccines. ANIMALS: 20 healthy juvenile domestic shorthair cats. PROCEDURE: Cats were injected with 2 doses of CLIDV at the standard dosage or 1 dose of CLIDV at 10 times the standard dosage; IDV was administered at the manufacturer-recommended dosage. Cats were observed for illness and reactions at inoculation sites. Periodically, samples were obtained for fungal culture, lymphocyte blastogenesis test (LBT) as an indicator of cell-mediated immunity against dermatophyte antigens, and antidermatophyte IgG titers. Following vaccination, cats were challenge-exposed by topical application of Microsporum canis macroconidia and examined weekly for clinical signs of dermatophytosis. RESULTS: of 10 cats given CLIDV developed focal crusts at the injection site that resolved without treatment; these were areas of dermatophyte infection with the vaccine strain. Antidermatophyte IgG titers increased significantly with all vaccination protocols. Cellular immunity against M canis increased slightly and variably during the vaccination period and did not differ significantly between vaccinated and control cats. All cats developed dermatophyte infection after challenge exposure. Vaccination with CLIDV or IDV was associated with slightly reduced severity of initial infection. CONCLUSIONS AND CLINICAL RELEVANCE: Noculation with IDV or CLIDV did not provide prophylactic immunity against topical challenge exposure with M canis. Inoculation with either vaccine did not provide a more rapid cure of an established infection.