Intracutaneous Tests Research Articles

Spätreaktion auf Röntgenkontrastmittel

Anaphylaktoide Symptome sowie Exantheme können Stunden bis Tage nach der Gabe von Röntgenkontrastmitteln (KM) auftreten. Bei einer Patientin kam es eine Stunde nach einer Kontrastmitteluntersuchung zu einer anaphylaktoiden Unverträglichkeitsreaktion und vier Tage später zu einem makulo-papulösen Exanthem im Sinne einer Typ-IV-Spätreaktion. In Epikutan- und Intrakutantesten mit einigen ionischen und nicht-ionischen KM konnten positive Reaktionen nach 24 und 48 Stunden gegen das nicht-ionische KM Iopamidol nachgewiesen werden. Positive Hautteste auf KM können auf einen möglichen immunologischen Mechanismus von Spätreaktionen auf KM hinweisen.

Specific immunotherapy in Albanian patients with anaphylaxis to hymenoptera venoms.

Severe allergic reactions during rush-specific immunotherapy (Rush-SIT) may occur in the treatment of hymenoptera sting allergy. The objective of the present study was to examine the characteristics of allergic reactions during Rush-SIT in a cohort of patients with allergy towards hymenoptera venom in the mediterranean population of Albania. A retrospective study was performed using the clinical reports of 37 patients with venom of bee (apinae), wasp (vespidae, subfamily vespinae) or paperwasp (vespidae, subfamily polistinae) allergy treated with Rush-SIT between 1987 and 1996. After hymenoptera sting allergy diagnosis according to anamnesis and intracutaneous tests the patient were treated with Rush-SIT. The protocol lasted 3 - 4 d with an increase in the concentration from 0.01 microg/ml to 100 microg/ml. Anaphylactic reactions were classified according to the Mueller-classification. The frequency of reactions during Rush-SIT for bee-venom was 4.7% and for wasp-venom was 1.5% (p < 0.01). The mean frequency of reactions of Mueller grade II for the bee-venom Rush-SIT patients during the first 4 d (= 26 injections) was 0.73 and for the wasp-venom Rush-SIT patients 0.15. No patient experienced a third-degree reaction. 94.6% of the patient supported an end dose of 100 microg. Rush-SIT is a reliable method for the treatment of anaphylactic reactions to hymenoptera venom even in less developed countries. Bee-venom Rush-SIT was found to cause higher numbers allergic reactions than wasp or paperwasp Rush-SIT.

Successful treatment of autoimmune chronic idiopathic urticaria with intravenous cyclophosphamide

A 45-year-old woman presented with a 20-year history of chronic idiopathic urticaria (CIU) unresponsive to H1- and H2-antagonists and combinations of other anti-inflammatory agents but controlled with daily prednisone (35 mg) for more than 13 years. Intracutaneous testing to autologous serum revealed an 8 x 10-mm wheal/flare reaction consistent with the presence of anti-Fc epsilonRIalpha autoantibodies. These autoantibodies have been reported to be present in >45% of patients with CIU. Their functional role in the pathogenesis of CIU remains poorly understood. Because of the therapeutic refractory nature of this patient's CIU requiring high doses of corticosteroids, it was decided to initiate treatment with intravenous cyclophosphamide (CTX) in an attempt to eradicate autoantibody-producing B-lymphocyte clones. This therapeutic approach has been previously successful in other autoantibody-mediated disorders such as type II acquired angioedema and factor VIII deficiency. Initial treatment consisted of 500 mg CTX intravenously followed by increases of 100 mg every 2 weeks, with the maximum dose reaching 1,500 mg once a month, which represents approximately 20% of the dose administered during systemic cancer chemotherapy. Within 7 months there was a complete clinical remission and prednisone was discontinued. Repeat intracutaneous testing to autologous serum was negative, consistent with an abrogated autoantibody response. The patient has not experienced a recurrence of CIU at the time of this report. This index case suggests that intravenous CTX may be effective in alleviating autoantibody-associated CIU in corticosteroid-dependent patients refractory to conventional therapies.

Recombinant Hymenoptera venom allergens.

Hymenoptera venoms, instead of the previously used whole body extracts, were introduced in the late 1970s for the diagnosis and treatment of IgE-mediated allergic reactions to stings by insects of the order Hymenoptera, such as honey bees and vespids (1, 2). Insect venom allergy is often considered as a model for IgE-mediated allergy: Diagnostic tests (skin tests and radioallergosorbant assays, RAST) are thought to be reliable, and specific immunotherapy with venoms is claimed to be safe and highly effective. However on closer looks the specificity of the main diagnostic tests (prick tests or intracutaneous skin tests with insect venom extracts, and tests for venom-specific serum IgE antibodies) is far from perfect. Up to 20% of individuals with no history of systemic sting reactions have positive tests. On the other hand only 30–50% of those with positive tests will react to a subsequent sting by the respective insect (3). According to a sting provocation test during venom immunotherapy around 95% of patients allergic to vespid stings are completely protected and do not develop any generalized allergic symptoms, while the complete protection rate achieved for those allergic to honey bee venom is only 80–90% (3, 4). Systemic allergic side-effects to immunotherapy injections may occur in 20–40% of patients during immunotherapy with honey bee venom and 5–10% during immunotherapy with vespid venoms (4). There is therefore considerable potential for improvement of both diagnosis and immunotherapy of Hymenoptera venom allergy. Thanks to modern molecular biology technology, recombinant venom allergens are available today and offer several promising approaches to achieve such an improvement. Expression of various recombinant allergens from Hymenoptera venoms

Intracutaneous tests with recombinant allergens in cystic fibrosis patients with allergic bronchopulmonary aspergillosis and Aspergillus allergy.

Allergic bronchopulmonary aspergillosis (ABPA), an intensive inflammatory reaction to Aspergillus fumigatus, can cause irreversible lung damage in patients with cystic fibrosis (CF). The aim of this study was to assess if intracutaneous testing with recombinant A. fumigatus allergens (rAsp f ) allowed a reliable diagnosis of ABPA. Fifty patients with CF were tested, 12 suffering from ABPA, 21 with allergy to A. fumigatus, and 17 CF control patients not sensitized to A. fumigatus. All patients with ABPA reacted to at least one of the two intracellular A. fumigatus allergens rAsp f 4, a 30-kD protein of unknown biologic function, and rAsp f 6, a 23-kD manganese superoxide dismutase, at a concentration of 10(-2) microg/ml. The intracutaneous tests were negative or only marginally positive in the patients with allergy to A. fumigatus and completely negative in the CF control patients. The differential responses to the recombinant A. fumigatus allergens were in perfect agreement with our previous serologic results, so that rAsp f 4 and rAsp f 6 can be considered specific markers for ABPA. Early diagnosis of the disease might help to prevent irreversible lung damage and minimize possible steroid-mediated side effects as a consequence of an optimized control of the disease.

Estudio clínico y alergológico en pacientes con manifestaciones cutáneas minor de dermatitis atópica

Abstract.—Background: the minor sings of atopic dermatitis can be the only manifestation of the process or to be a part of the florid disease. Their importance for the diagnose has been object of multiple studies. Objetive: to relate the minor cutaneous manifestations of atopic dermatitis with the atopic constitution, personal and family history and the interrelation with the environmental factors. Methods: fifty children with minor atopic cutaneous manifestatios were investigated. Clinical and analytic exploration, and epidermic and intracutaneous test (True Test®, acari, foods) were performed. Conclusions: minor criteria seem to be more indicative of the atopic consitution than of atopic eczema, in the last, both environment and inheritance influence in an important way. Eosinophils and IgE levels were not related with the intensity of cutaneous process, but with the intensity of the respiratory process and the hypersentivity to acari. Foods did note related with cutaneous manifestations.

Epidemiology, clinical features, and immunology of the "intrinsic" (non-IgE-mediated) type of atopic dermatitis (constitutional dermatitis).

Departmentof Pharmacology, University of Bern, Bern, SwitzerlandKey words: atopic dermatitis; clinical features;constitutional dermatitis; epidemiology; extrinsictype; immunopathology; intrinsic type.Prof. Dr B. Wu¨thrichAllergy Unit, Department of DermatologyUniversity Hospital8091 ZurichSwitzerlandAccepted for publication 22 March 2001

Cutaneous reactions to anticoagulants. Recognition and management.

Anticoagulant-induced skin reactions appear as allergic or necrotic responses to vitamin K antagonists or heparins. Cutaneous allergy has been reported with danaparoid sodium and flush reactions have been seen with hirudins. The pathogenesis of the reactions differs between drugs. Generally, they occur between days 3 to 10 after the start of treatment, but may also occur later. In patients experiencing necrosis with a vitamin K antagonist, concomitant protein C deficiency, protein S deficiency or lupus anticoagulant has been described, whereas the precise mechanism of the other reactions is unknown. In patients with allergic reactions to heparins, cutaneous tests may help to identify alternative anticoagulants. Such a test cannot be performed in patients with skin necrosis. In patients with heparin-induced skin reactions danaparoid sodium may be used after negative intracutaneous testing in some patients and a hirudin may be used without testing in all patients. Heparin-induced skin necrosis has been reported to be mediated by immunologic mechanisms and to be associated with a high frequency of heparin-induced thrombocytopenia type II. Surgical excision of the necrosis may be required. If further anticoagulation is indicated in any patient, extreme caution has to be taken when restarting oral anticoagulants. Because a large number of anticoagulants available today, safe treatment of all patients experiencing anticoagulant-induced skin reactions is feasible.

Skin prick tests may give generalized allergic reactions in infants

Skin prick testing, a widely used method of studying sensitization, is usually considered quick, pedagogic, and relatively inexpensive. Previous studies have shown very few negative reactions and no fatalities. In contrast, both anaphylaxis and death have been reported as a result of intracutaneous tests. To examine detailed case studies of generalized allergic reactions in connection with skin prick testing in order to identify possible risk factors and thereby increase the safety of the test procedure. A retrospective study of medical records of six cases with generalized allergic reaction occurring during the study period 1996-1998 at the Pediatric Clinic, University Hospital of Linköping, Sweden. Data about the total number of children tested during the period were collected from the clinic's database. All six cases with generalized reactions were infants <6 months who showed positive skin prick tests to fresh food specimen. Other common features were active eczema and a family history of allergic disease. All infants received prompt treatment and recovered well. The overall rate of generalized reactions was 521 per 100,000 tested children. In the age group <6 months, the corresponding figure was 6,522 per 100,000. The risk of generalized reactions after skin prick test with fresh food specimens in young children ought to be acknowledged and should lead to increased precautions when performing the test.

Cutaneous Reactions to Rubber

Abstract The three major adverse cutaneous reactions to rubber include natural rubber latex allergy, irritant contact dermatitis and allergic contact dermatitis. An overview of relevant aspects of the types of natural and synthetic rubber, rubber production, and specific chemicals used in compounding and vulcanization, as well as latex proteins is essential to an understanding of these reactions. Natural rubber latex allergy is a type I, IgE mediated, immediate hypersensitivity reaction to one or more proteins present in natural rubber latex with clinical manifestations ranging from contact urticaria to allergic rhinitis, asthma, and anaphylaxis. Over the past decade, natural rubber latex allergy has become a major medical, occupational health, and medicolegal problem. Individuals at highest risk are patients with spina bifida and health care workers. Diagnosis is based largely on clinical history and examination, and serologic and intracutaneous testing. Irritant contact dermatitis is non-immunologic and is the most common cutaneous reaction to rubber. Cumulative exposure to low-grade irritants impairs the barrier function of the skin and allows penetration of potential irritants and allergens. Diagnosis is based on history of exposure to known irritants, cutaneous examination, and exclusion of allergy. Allergic contact dermatitis is a type IV cell mediated, delayed hypersensitivity reaction which occurs primarily from exposure to rubber chemicals either directly or from residual amounts present in rubber products. Most cases present with an eczematous dermatitis, but purpura, lichenoid dermatitis, and depigmentation occasionally occur. Diagnosis is made on the basis of history, examination, and epicutaneous patch testing with rubber chemicals and rubber products. Treatment is with allergen and irritant avoidance and substitution, environmental control, personal protective equipment and topical and systemic pharmacologic therapy. A unified approach is needed in the diagnosis and treatment of adverse cutaneous reactions to rubber and it is important to remember that some patients may have both contact dermatitis and natural latex allergy. Determining the bioavailability and elicitation threshold of rubber allergens may be helpful in reducing allergic reactions from consumer and industrial rubber products.

Delayed-type hypersensitivity skin reactions caused by subcutaneous unfractionated and low-molecular-weight heparins: Tolerance of a new recombinant hirudin

Eczema-like infiltrated plaques at subcutaneous heparin injection sites are well-documented side effects of these anticoagulants. However, surgical interventions may be problematic if heparin is urgently needed in these patients. The aims of this study were to perform extensive allergy skin testing in 24 patients, including a pregnant woman in whom subcutaneous infiltrated plaques developed after subcutaneous heparin injections, and to find safe therapeutic alternatives for this group of patients. Patch, intradermal, and subcutaneous tests were performed with a panel of unfractionated heparins (UFHs), low-molecular-weight heparins (LMWHs), and heparinoids. Since 1997, we have also been performing allergy studies in 8 patients with lepirudin, a new recombinant heparinoid; tolerance of lepirudin was investigated by means of subcutaneous and intravenous injections. The allergy investigations in the pregnant woman were limited to patch tests with heparins and intradermal and subcutaneous tests with pentosanpolysulfate, which are not contraindicated during pregnancy. In our study population 19 of 23 patients were sensitized to all the UFHs and LMWHs tested when intracutaneous and subcutaneous test results were read at up to 96 hours. LMWH was found to be a possible substitute in 4 patients. Five patients were also sensitized to the heparinoid pentosanpolysulfate. Sensitization to the heparinoid danaparoid was observed in 12 of the 13 patients who were tested with this substance. The administration of an intravenous bolus containing a therapeutic dose of lepirudin after negative subcutaneous provocation was tolerated without any side effects in all 8 patients. The pregnant woman was sensitized to LMWH but tolerated subcutaneous pentosanpolysulfate without any side effects. Extensive allergy skin testing should be performed to find safe alternatives. With few exceptions, all patients react to both UFHs and LMWHs, as well as to danaparoid. The subcutaneous provocation test is the most reliable diagnostic measure. Intravenous lepirudin, and in some cases subcutaneous pentosanpolysulfate, appears to be a safe alternative in patients with eczema-like infiltrated plaques at subcutaneous heparin-injection sites.

Delayed-type hypersensitivity skin reactions caused by subcutaneous unfractionated and low-molecular-weight heparins: Tolerance of a new recombinant hirudin

Background: Eczema-like infiltrated plaques at subcutaneous heparin injection sites are well-documented side effects of these anticoagulants. However, surgical interventions may be problematic if heparin is urgently needed in these patients. Objective: The aims of this study were to perform extensive allergy skin testing in 24 patients, including a pregnant woman in whom subcutaneous infiltrated plaques developed after subcutaneous heparin injections, and to find safe therapeutic alternatives for this group of patients. Methods: Patch, intradermal, and subcutaneous tests were performed with a panel of unfractionated heparins (UFHs), low-molecular-weight heparins (LMWHs), and heparinoids. Since 1997, we have also been performing allergy studies in 8 patients with lepirudin, a new recombinant heparinoid; tolerance of lepirudin was investigated by means of subcutaneous and intravenous injections. The allergy investigations in the pregnant woman were limited to patch tests with heparins and intradermal and subcutaneous tests with pentosanpolysulfate, which are not contraindicated during pregnancy. Results: In our study population 19 of 23 patients were sensitized to all the UFHs and LMWHs tested when intracutaneous and subcutaneous test results were read at up to 96 hours. LMWH was found to be a possible substitute in 4 patients. Five patients were also sensitized to the heparinoid pentosanpolysulfate. Sensitization to the heparinoid danaparoid was observed in 12 of the 13 patients who were tested with this substance. The administration of an intravenous bolus containing a therapeutic dose of lepirudin after negative subcutaneous provocation was tolerated without any side effects in all 8 patients. The pregnant woman was sensitized to LMWH but tolerated subcutaneous pentosanpolysulfate without any side effects. Conclusion: Extensive allergy skin testing should be performed to find safe alternatives. With few exceptions, all patients react to both UFHs and LMWHs, as well as to danaparoid. The subcutaneous provocation test is the most reliable diagnostic measure. Intravenous lepirudin, and in some cases subcutaneous pentosanpolysulfate, appears to be a safe alternative in patients with eczema-like infiltrated plaques at subcutaneous heparin-injection sites. (J Am Acad Dermatol 2000;42:612-9.)

Chronic urticaria serum induces histamine release, leukotriene production, and basophil CD63 surface expression—Inhibitory effects of anti-inflammatory drugs

Background: A role of potential histamine-releasing autoantibodies against the high-affinity IgE receptor on the surface of basophils and mast cells is discussed in the pathogenesis of chronic urticaria. This so-called autoimmune urticaria may be diagnosed by a positive intracutaneous autologous serum skin test, which is found in about 30% of patients with chronic urticaria. Objective: Our purpose was, first, to compare the effect of complement-inactivated sera of 20 patients with chronic urticaria and positive autologous serum skin tests, 20 patients with chronic urticaria and negative skin tests, and 20 control subjects without chronic urticaria (10 atopic and 10 nonatopic subjects) and, second, to analyze the effect of anti-inflammatory drugs on the serum activity. Methods: The following assay systems were used: release of histamine in whole blood samples, surface expression of the activation marker CD63 on basophils, and sulfidoleukotriene de novo production in leukocyte suspensions. Whole blood, basophils, and leukocyte suspensions were obtained from a nonatopic and an atopic donor. Results: Sera of patients with autologous serum skin test positive chronic urticaria resulted not only in significantly increased histamine release compared with skin test–negative chronic urticaria sera but also in a significant higher induction of basophil CD63 surface expression and sulfidoleukotriene de novo production. However, serum activity was neither characteristic for chronic urticaria nor for chronic urticaria with a positive autologous serum skin test. Preincubation with dapsone, chloroquine, and lidocaine dose dependently resulted in a significant reduction of all histamine release, CD63 expression, and sulfidoleukotriene production. In addition, mizolastine was able to inhibit serum-induced sulfidoleukotriene production. Conclusion: Further studies investigating the in vivo effect of these drugs will have to clarify their role in the management of the subset of patients with chronic urticaria demonstrating serum-induced inflammatory effects. (J Allergy Clin Immunol 2000;105:552-60.)

Klinische Bedeutung allergischer Reaktionen bei Glukokortikoidbehandlung

Glucocorticoids are widely used in medicine. Within the last few years, however, patients have become very suspicious of corticoids. The attending physicians frequently has to use a great deal of persuasion prior to applying this very effective and often indispensable group of medication. We report on four patients who developed allergic reactions (i.e. erythema in face and on body, itching, flushing, drop in blood pressure, respiratory distress, cold sweats, etc.) immediately after intravenous administration of prednisolone-21 hydrogen succinate (Solu-Decortin H, SDH). Three out of four patients had a positive reaction to an intracutaneous test with SDH, but no reaction to the additive sodium succinate. The prick test was negative in all patients. No specific IgE antibodies were detected in the serum of these patients. However allergic reaction to SDH must be presumed in at least three cases as it is difficult to detect glucocorticoid antibodies in serum and standardizes techniques are lacking. One female patient had a cross-reaction to prednisolon and dexamethasone. A renewed application of SDH was tolerated well by all patients when H1- and H2-receptors were blocked and calcium was administered to stabilize membranes. Allergic reactions after glucocorticosteroid therapy are only occasionally mentioned in literature, appear more often when the agent is applied topically, and may lead to dangerous complications in patients if administered intravenously. Therefore, when allergic reactions result from glucocorticoid therapy (immediate reactions should be suspect), corticosteroid allergy should be considered as a differential diagnosis.

Atopy patch testing--a diagnostic tool?

Atopy patch testing--a diagnostic tool?

STINGING INSECT HYPERSENSITIVITY: A PRACTICE PARAMETER

STINGING INSECT HYPERSENSITIVITY: A PRACTICE PARAMETER

Association of heparin-induced skin lesions, intracutaneous tests, and heparin-induced IgG.

Cutaneous heparin-induced allergic reactions to subcutaneous heparin may begin 2-5 days after administration. The relation of the delayed-type hypersensitivity and a systemic immunologic response is controversial. The present investigation aimed to analyze the occurrence of thromboembolic complication, pathologic heparin-induced platelet activation (HIPA), and the presence of circulating heparin-induced IgG in patients with heparin-induced skin reactions. Intracutaneous tests, HIPA assay, and heparin-heparin IgG antibodies were performed in nine patients with heparin-induced skin lesions. Six of eight patients showed positive intracutaneous tests to heparin and to four low-molecular-weight heparins. Three of six heparin-positive patients presented hypersensitivity to a heparinoid, too. Two of three patients had a positive HIPA test and elevated heparin-induced IgG antibodies. Both patients developed complications presenting as heparin-induced skin necrosis or arterial thrombosis. Two of nine patients were treated with danaparoid, 4/9 patients received r-hirudin, and 1/9 received oral coumarin. In 2/9 patients, anticoagulant therapy was stopped, but these patients will receive r-hirudin if indicated. On the basis of the coincidence of local and systemic hyperreactivity to heparin and danaparoid, patients with heparin-induced skin lesions should receive r-hirudin, a nonheparin compound, for anticoagulant treatment.

Bronchial allergen challenge in subjects with low levels of allergic sensitization to indoor allergens.

Low skin reactivity to common inhalant allergens is frequently found in asymptomatic individuals as well as in patients with respiratory complaints. However, most studies on bronchial allergen challenge concern patients with high levels of allergic sensitization. The present study was directed to bronchial reactions after allergen challenge in subjects with low skin reactivity to Dermatophagoides pteronyssinus or cat dander. Titrated intracutaneous skin tests, skin prick tests, specific IgE assays, histamine release on washed leukocytes, and bronchial histamine and allergen-challenge tests were performed in 20 subjects with an intracutaneous skin test threshold for cat dander (Felis domesticus) or D. pteronyssinus above 0.1 BU/ml (mean wheal diameter in skin prick test with 10000 BU/ml: 4.4mm). Ten of the 20 patients had specific IgE below the detection limit in at least one of the three IgE assays which were done. Fifteen patients had a specific IgE level below 2 kU/I in all three tests. As a positive control group, the same parameters were studied in seven moderately sensitized patients with an intracutaneous skin test threshold below 0.1 BU/ml (mean wheal diameter with 10000 BU/ml: 7.2mm). The 20 subjects with low levels of allergic sensitization had an early decrease in FEV1 of 8.6% (P<0.01) and a mean late decrease of 6.3% (P<0.05). There was a trend for decrease in PC20 histamine 24h after allergen challenge (-0.4 doubling doses, P=0.09). In this group of subjects with low levels of allergic sensitization, a statistically significant early and late decrease in FEV1 was found. However, the decrease in lung function was small and unnoticed by most patients. The increase in nonspecific bronchial hyperresponsiveness after bronchial allergen challenge did not reach statistical significance in the study group. The results indicate that allergen exposure in patients with low levels of allergic sensitization may lead to airways changes in the absence of acute symptoms.

Asthma and chemical bronchitis in vanadium plant workers.

Whether vanadium induces bronchial hyperresponsiveness and asthma in previously normal subjects is unresolved: the two reported series addressing this question both have shortcomings. To determine the cause of cough and breathlessness in vanadium plant workers after variable periods of exposure. Case series of employees presenting with persistent symptoms over a 24-month study period. Forty of an estimated 1,440 patients were investigated by 1) blood count and serum IgE, 2) intracutaneous allergen skin tests, 3) spirometry, and 4) bronchoprovocation by histamine inhalation or exercise challenge. Exposure was assessed by measurement of 1) ambient V2O5, NH3 and SO2 over 7 days during the 24-month study period, 2) urine vanadium concentration at time of first presentation. Twelve of 40 subjects had bronchial hyperreactivity (BHR), and these were compared to 12 age-matched companion subjects whose BHR was normal. In 10, BHR was diagnosed by histamine inhalation (PC20 0.25-1.82 mg/ml, nl > 8.0 mg/ml), and in six of these the abnormality was severe (PC20 < 0.5 mg/ml). A further two had BHR by exercise challenge (FEV1, 600 ml/30% and 770 ml/18% pre/post exercise). After removal from exposure, 9 of the 12 subjects returned for follow-up 5 to 23 months later. BHR was worse in one, still present although less severe in five, and was no longer found in one subject. Baseline spirometry measurements were normal in seven subjects and only mildly impaired in the remaining five of the 12 subjects with BHR. This study provides strong supporting evidence that inhaled V2O5 induces BHR and asthma in subjects previously free of lung disease; the abnormality may persist for up to 23 months following exposure; routine spirometry will not detect affected subjects.

Equine glanders in Turkey

In the course of an epidemiological study of glanders on a number of Turkish islands in the Sea of Marmara, 1128 horses were examined by using the intracutaneous mallein test....