Basophil responsiveness in patients with insect sting allergies and negative venom-specific immunoglobulin E and skin prick test results

Background Current guidelines do not adequately address the question of how best to manage patients with a convincing history of insect allergy, but negative venom-specific IgE and skin test results.
Methods Forty-seven patients out of a total of 1219 (4%), with a positive history of sting allergy, were recruited over a period of 4.5 years. All recruited patients had a convincing history of a severe or a life-threatening anaphylactic reaction of Mueller grade II–IV (median grade III) after Hymenoptera sting, but negative venom-specific IgE and skin prick test results. Diagnostic work-up was prospectively followed by the CD63 basophil activation test and by intradermal skin testing. A control group of 25 subjects was also assessed.
Results Thirty-five out of 47 (75%) patients demonstrated a positive basophil CD63 response after stimulation with bee and/or wasp venom. Intradermal venom skin tests were performed for 37 patients, 17 (46%) of whom showed positive results. Out of 20 patients who demonstrated negative intradermal test results, 12 patients showed a positive CD63 response (60%). In contrast, out of 9 patients who showed a negative CD63 response, only one was detected by intradermal testing (11%). In the control group, only two out of 25 (4%) subjects displayed a positive basophil response and/or intradermal test.
Conclusion Here we show that, in complex cases with inconclusive diagnostic results, the CD63 activation test could be particularly useful and more sensitive than intradermal skin testing.     

Histamine control affects the weal produced by the adjacent diluent control in skin prick tests

The effect of histamine chloride control (10 mg/ml) on the weal reaction produced by the adjacent test solution (buffered glycerol-saline diluent control) in skin prick tests was studied among 270 peat workers and 214 lumberjacks. The diluent control was placed on the skin at two test sites: 3-4 cm and 18-19 cm from the site of the histamine control. Prick-test lancets (Dome/Hollister-Stier) were used to prick the skin. Weal areas of 6 mm2 or larger were considered to be positive reactions. In both populations the diluent control caused positive reactions nearly three times more often when the test site was 3-4 cm from the site of the histamine control than when it was 18-19 cm away from the control (P less than 0.001). Similar relationships might be found between histamine control and allergen solutions. This finding should be taken into account in histamine-based standardisation of the results of skin prick tests as well as in biological standardization of allergen solutions.     

Diagnosis of Polistes wasp hypersensitivity

Patients referred from the Houston, Texas, metropolitan area were evaluated for allergic reactions to insect stings. Forty-eight persons reported at least one systemic reaction caused by a Polistes paper-nest wasp sting. Honey bees, imported fire ants, and other types of Hymenoptera were identified in that order by 19 other subjects with systemic allergic reactions. Life-threatening airway obstruction and/or hypotension were noted by most of our patients. Wasp venom skin testing was positive in 65% of subjects reporting sensitivity to this insect. Skin testing was correlated quantitatively with basophil histamine release, and qualitatively with RAST assays using Polistes wasp venom. Venoms from common species of Polistes were highly cross-reactive as shown by RAST and basophil histamine release. Patients having a positive history and laboratory response (by skin testing, histamine release, or RAST) to Polistes wasp venom also were positive to bee venom about 20% of the time and to another vespid (hornet or yellow jacket) over 50% of the time.     

Diagnostic value of the skin-prick test and RAST assay in insect sting allergy

The results of skin-prick tests to four concentrations of venom (0.1, 1, 10 and 1000 μg/ml) carried out on two occasions were analysed in relation to the history of adverse reactions to stings and to the level of venom-specific IgE antibody in serum, in forty-two subjects allergic to insect stings (sixteen to bee and twenty-six to wasp). Fifty control subjects (some of whom had never been stung by bee or wasp) with no history of adverse reaction to stings were also studied. No subject gave a positive skin-test reaction to 0.1 μg/ml, and small numbers reacted to either 1 or 10 μg/ml. The lowest concentration of venom to which most subjects had a positive skin test was 100 μg/ml. Our data suggest that in wasp-allergic patients a positive skin test to 100 μg/ml is normally significant (reflecting the presence of specific IgE), whereas in bee-allergic patients a skin test reaction to 100 μg/ml is usually non-specific for the following reasons. (i) In the allergic patients when skin tests were repeated, a reaction to 100 μg/ml bee venom often became negative (in six of eight), whereas for wasp venom the reaction became more positive (at 10 or 1 μg/ml) in seven of eight patients. Whilst this might reflect lack of reproducibility, the consistent direction of change for either bee or wasp venom suggests responses to this concentration of these venoms may have different interpretations. (ii) In bee-allergic patients, where positive skin tests to 100 μg/ml wasp venom were found they were repeatable in all patients, and occurred only in patients who had been stung by a wasp. In wasp-allergic patients, skin test reactions to 100 μg/ml bee venom were not reproducible between studies in any patient and often occurred in subjects never stung by a bee. (iii) A better correlation between skin test and RAST occurred for wasp venom when a skin-test reaction to 100 μg/ml was included as a positive (rather than reactions to 1 or 10 μg/ml only). For bee venom the correlation did not improve when skin-test reactions to 100 μg/ml were included. (iv) In the control group, skin-test reactions to 100 μg/ml bee venom were often false positives (seven of eight had never been stung by a bee). Four out of fifty controls reacted to wasp venom 100 μg/ml, but three of these had received a wasp sting. These findings suggest that in routine clinical practice skin tests should be carried out over the range 1–10 μg/ml in bee-allergic subjects but in wasp-allergic patients 100 μg/ml should also be included. Extracts of 0.1 μg/ml need not be used.     

Skin and radioallergosorbent tests in patients with sensitivity to bee and wasp venom

Intradermal (ID) and prick tests with bee or wasp venom (Pharmalgen) have been performed on 102 subjects with a history of adverse reactions to stings and forty-six control subjects giving no such history. Venom was diluted 100, 10 and 1 μg/ml for prick testing and 10^-2, 10^-2, 10^-3 and 10^-4%mUg/ml for ID injections. In forty-six control subjects all were tested with the highest concentration of prick testing solution (100 μg/ml), eight (17%) had positive reactions, a similar reaction rate to that reported in control subjects using 10^-1μg/ml ID. In our 102 test subjects skin tests were therefore regarded as positive only if the reaction was elicited by 10^-2μg/ml or less by prick test of 10^-2μg/ml or less ID. In general the results with skin prick tests and ID tests were comparable when the prick solution was 1000 times the concentration of that used for ID testing. ID tests were positive in thirteen with negative skin prick, seven of whom had detectable antibodies when tested by RAST. Conversely four with a positive skin prick test (two of whom were RAST positive) were considered negative on ID testing. As judged either by RAST or skin tests it appeared that sensitivity diminished with the time interval from the last sting (P< 0-001).     

Insect Allergy

One hundred and seventeen persons all stung by yellow jacket (YJ) and/or bee were examined by means of skin prick test with venom of these insects, skin prick test with 10 inhalant allergens and analyses of total IgE. Specific IgE and IgG against honey bee and YJ venom. Eighty-seven persons had had a systemic reaction. Positive correlations ( P < 0.05) were found between results of skin prick tests and specific IgE against venoms and, for YJ, between the severity of symptoms after sting and the size of skin prick test with the venom. That some of the more severe symptoms could have been caused by non-immunological mechanisms could explain why a significant correlation was present only between the results of the prick test and specific IgE and not between these tests and the clinical symptoms. Specific IgE values against YJ and honey bee venom showed convariation, although no correlation could be demonstrated between the clinical symptoms after stings from these insects, or between skin prick test results using the two different extracts. The severity of the sting reactions was not correlated to age, atopic disposition, amount of total IgE, number of stings during life, or positive skin prick test to inhalant allergens. It is concluded that in insect allergy, specific IgE analysis and skin prick tests are supplementary.     

Clinical symptoms and immunologic reactivity to bee and wasp stings in beekeepers

We compared the history of sting reactions with venom skin prick test (SPT) and CAP RAST reactions in beekeepers in order to assess the value of structured questions and symptom backgrounds. The study population consisted of 102 beekeepers, who were 25–75 years of age. Bee and wasp venom SPT was performed with concentrations of 10, 100, and 300 μg/ml. The CAP Phadiatop® test was used in the screening of IgE antibodies against common inhalant allergens. Eorty-two beekeepers had never experienced large local or systemic reactions after a bee sting. Of the 31 subjects with a history of systemic reactions, 13 had experienced these during the previous year. A significant difference ( P <0.01) between systemic reactors and nonreactors was found in bee venom CAP and SPT (300 μg/ml). However, due to considerable overlap, these tests are unable to discriminate between allergic and nonallergic beekeepers. Both bee venom SPT (300 μg/ml) and CAP tests were positive in 65% of systemic reactors and in 34% of nonreactors ( P =0.008). Venom SPT (300 μg/ml) correlated significantly with CAP for both venoms. No correlation was observed between venom allergy and atopy. Clinically, the most practical concentration for evaluating bee and wasp venom sensitization by SPT proved to be 300 μg/ml.     

Recombinant allergens for skin testing.

Skin testing is a basic diagnostic procedure widely used to explore immediate-type reactions to allergen preparations in vivo. Despite their reliability, if standardized extracts are used, skin tests suffer from limited reproducibility due to difficulties in preparing consistently standardized extracts from natural raw material. Starting from allergen-encoding cDNAs, large amounts of highly pure allergens with a high batch-to-batch consistency satisfying the quality requirements of medicinal products manufactured by recombinant DNA technology can be produced. These reagents are expected to be qualitatively superior to the commercially available allergen preparations used for the in vitro and in vivo diagnosis of allergic conditions. In this article the current literature available on skin testing with such recombinant allergens (rAllergens) is reviewed and critically analyzed. To date many different rAllergens of various pollens, moulds, mites, bee venom, latex and celery have been used in skin testing in more than 1,600 allergic and control individuals. Skin prick tests as well as intradermal skin tests with rAllergens prove to be highly specific and safe. The diagnostic sensitivity of single rAllergens is generally lower than those obtained with allergen extracts, but can be considerably increased by using rAllergen panels covering the most important allergenic structures present in a given complex allergenic extract. Moreover, quantitative skin testing with single rAllergens allows interesting insights into correlations between the in vivo and in vitro sensitization to a given allergen. In conclusion, skin testing with rAllergens offers a highly specific and safe additional diagnostic tool to elucidate patient- and disease-specific sensitization patterns which will be needed for the development of patient-tailored immunotherapeutic treatments.     

Three cases of centipede allergy--analysis of cross reactivity with bee allergy]

BACKGROUND: We experienced three cases of patients who suffered from systemic urticaria and systemic symptoms such as general fatigue and dyspnea which occurred just after the sting of centipede. The result of prick test by centipede venom revealed positive reaction in all three patients, so we diagnosed the symptoms of them as immediate type allergic reaction against centipede venom. And more there have been some reports documented the relationship between centipede allergy and bee allergy, so we added the examination about bee allergy on these three patients. METHODS: The measurement of bee venom specific IgE was practiced on all three patients and intradermal skin test about bee venom was done only on one patient. Moreover we also practiced prick test of centipede venom against another three patients who were diagnosed as having bee allergy. RESULTS: All patients of centipede allergy showed positive reaction for the specific IgE antibody of Wasp and/or Honeybee and one patient who was practiced skin test also reacted positively against Wasp and Yellow Jacket venom. But none of three patients of bee allergy showed positive reaction against centipede venom. CONCLUSION: According to these results we suspected that there lies some relationship between centipede allergy and bee allergy. But it is supposed that only little involvement of centipede allergy was concerned among the patients of bee allergy. Until now there have been only a few reports as to the centipede allergy. But actually we guess it may be the phenomenon that could occur frequently.     

Anaphylaxis caused by the new ant, Pachycondyla chinensis: demonstration of specific IgE and IgE-binding components

BACKGROUND: There have been no reports dealing with the pathogenic mechanism and IgE-binding components in patients with anaphylaxis caused by a sting from Pachycondyla chinensis. OBJECTIVES: This study was conducted to observe the clinical features of patients with P chinensis -induced anaphylaxis. The roles of specific (s) IgE and sIgG4 antibodies were evaluated, and IgE-binding components were identified. METHODS: Seven patients with P chinensis -induced anaphylaxis and 15 unexposed control subjects were enrolled. P chinensis ants were collected at the patients' homes, and venom was prepared as P chinensis extract. Five patients complained of bee venom-induced anaphylaxis and had positive sIgE levels to yellow jacket venom, wasp venom, or both as well. Serum sIgE and sIgG4 were detected by means of ELISA. To identify IgE-binding components within P chinensis extracts, 12% SDS-PAGE with immunoblot analysis was applied. RESULTS: All patients had positive skin prick test responses to P chinensis antigen and positive sIgE levels. Five (71%) patients had positive sIgG4 levels. Eight IgE-binding components (58, 46, 3l, 29, 27, 25, 22, and 12 kd) were noted, and the component at 12 kd was the most frequently found allergen (85%). IgE ELISA inhibition tests were performed on 2 groups of sera: one from patients with anaphylaxis induced by both P chinensis and bee venom (group A) and the other from patients with anaphylaxis induced by P chinensis venom alone without bee venom allergy (group B). ELISA inhibition tests with serum from group A showed significant inhibitions with addition of P chinensis extract, partial inhibitions with yellow jacket antigen, and minimal inhibitions with wasp or imported fire ant antigens. However, ELISA inhibition tests with serum from group B showed significant inhibitions with P chinensis antigen but no inhibition with wasp, yellow jacket, or imported fire ant antigens. CONCLUSIONS: IgE-mediated reactions contributed to the development of P chinensis -induced anaphylaxis. Eight IgE-binding components and one major allergen (12 kd) were identified. Further studies will be needed to clarify the role of sIgG4 and to identify allergenic relationships with major bee and wasp allergens.     

Agreement of skin test with IL-4 production and CD40L expression by T cells upon immunotherapy of subjects with systemic reactions to Hymenoptera stings

Venom immunotherapy is the only curative intervention for subjects with Hymenoptera venom allergy who suffering systemic reactions upon bee or wasp stings. Venom immunotherapy can restore normal immunity against venom allergens, as well as providing to allergic subjects a lifetime tolerance against venoms. Nevertheless, it is necessary using safety assays to monitoring the development of tolerance in the VIT protocols to avoid fatal anaphylactic reactions. The purpose of this study was to assess the modifications in several markers of tolerance induction in subjects with Hymenoptera venom allergy undergoing immunotherapy. The studies were performed at baseline time and after six month of VIT. Intradermal skin tests, basophil activation tests, specific IgE levels; and the T-cell markers (IL-4 and IFN-γ producing cells; and expression of the surface activation markers CD40L and CTLA-4) were assayed. At six month of imunotherapy all parameters studied had significant alterations. All decreased, except the IFN-γ producing cells. In addition, modifications in intradermal skin test showed a significant correlation with both, CD40L expression on CD4 T lymphocytes (p = 0.043) and IL-4 producing T lymphocytes (p = 0.012). Neither basophil activation test nor serum levels of sIgE demonstrated any correlation with the immunological parameters studied nor among them. These results suggest that both IL-4 production and CD40L expression could be two good indicators of the beneficial effects of venom immunotherapy which translate into skin tests.     

Simplification of intradermal skin testing in Hymenoptera venom allergic children

Background

The direct comparison between children and adults with Hymenoptera venom anaphylaxis (HVA) has never been extensively reported. Severe HVA with IgE-documented mechanism is the recommendation for venom immunotherapy, regardless of age.

Variations in skin tests before and after immunotherapy in allergic asthma

The clinical relevance of positive intradermal and prick skin tests were evaluated on 195 patients with allergic asthma subjected to prick test and intradermal tests before and after 3 years of immunization. Satisfactory clinical improvement followed immunotherapy based on the results of intradermal skin tests. Skin reactivity may change in time with or without immunotherapy.     

Role of intradermal skin tests in the evaluation of clinically relevant respiratory allergy assessed using patient history and nasal challenges.

BACKGROUND: Skin testing, correlated with patient history, is the accepted method of identifying clinically relevant aeroallergen sensitivity. Traditionally, intradermal tests are believed to be more sensitive in identifying aeroallergen sensitivity than the epicutaneous and percutaneous methods. Therefore, many allergy practitioners use the epicutaneous or percutaneous method first and, if the results are negative, follow up with intradermal tests. OBJECTIVES: To compare the epicutaneous, percutaneous, and intradermal methods to determine their sensitivity to patient history and to evaluate the value of intradermal tests when epicutaneous and percutaneous test results are negative. METHODS: Participants were evaluated for rhinoconjunctivitis symptoms and then were skin tested using the prick and Multi-Test II (MTII) methods. Intradermal tests were performed when prick and MTII test results were negative to an aeroallergen. Participants with negative prick and MTII test results and corresponding positive intradermal test results underwent nasal challenges with evaluation by anterior rhinomanometry. RESULTS: Compared with patient history, average sensitivity for MTII was 77% and for the prick method was 62%. When MTII results were negative, 17% of intradermal tests corresponded with probable patient histories of allergy but none with positive nasal challenge results. Nasal challenge results were similar to those of the negative control group and significantly different from those of the positive control group (P < .001). CONCLUSIONS: The MTII tests are more sensitive and equally specific compared with the prick method. When MTII results are negative, positive intradermal test results are unlikely to identify clinically relevant aeroallergen sensitivity. Routine performance of intradermal tests when MTII results are negative is likely to be of low clinical yield.     

The use of the radioallergosorbent test in the diagnosis of Hymenoptera anaphylaxis

IgE antibody levels to Hymenoptera (honey bee, hornet, wasp or yellow jacket) venom or venom sac were measured in the serum of ninety-six patients with a history of immediate hypersensitivity reactions to these insect stings. Normal levels of IgE antibody were found in fourty-four of these patients tested. The severity of the systemic reaction was similar in those patients with normal and elevated IgE antibody levels, and the interval from the systemic reaction to antibody determination was also similar. In twelve patients with a definite reaction to honey bee venom, the IgE antibody was elevated in all and correlated with a positive venom skin test in nine out of the twelve. It is not possible to determine if the other patients with normal IgE antibody and a systemic reaction represent a false negative RAST value, loss of sensitivity to the Hymenoptera venom, or a lack of RAST sensitivity with some venom or venom sac antigens. Without the ready availability of venom skin tests to all Hymenoptera antigens or other in vitro tests, a definite assessment of insect anaphylaxis remains in doubt for the patient and physician.     

Reproducibility of the skin prick test

Reproducibility of the skin prick method of testing for allergy was studied in 20 subjects examined by four nurses. Hypodermic needles were used for pricking and the test panel included a histamine control, a diluent control, and nine allergens. The reproducibility of the method was best when the size of the weal reaction caused by an allergen was expressed as the geometric area of the weal. When the weal reaction was expressed as the ratio of the weal reaction caused by an allergen to that caused by histamine, the reproducibility of the method was decreased considerably. When the ratios were further classified into three class ratings, reproducibility was very low. The reduction in reproducibility was due to the low reproducibility of histamine reactions. According to these results, at least in epidemiological studies the weal reactions should be expressed as geometric areas. In clinical practice it might also be preferable to express prick test results as the diameters of the weals without adjusting them by histamine reactions.     

Studies on antibiotic skin testing

Commercially available antibiotics for injection are supplied with test ampules. Users are instructed to dissolve them to make 300 micrograms/ml solution for intradermal pretests to avoid allergic reactions. Sometimes this concentration is too low to prevent anaphylactic reactions. In the present study, we tried to find the maximum concentration for the intradermal tests which would have high sensitivity without giving nonspecific, false positive reactions. We investigated intradermal tests with cephalothin (CET) in a patient who suffered from anaphylaxis after drip infusion with CET, although she was judged to be negative to CET by the usual intradermal test prior to the infusion. Her CET skin test was negative at a concentration of 150 micrograms/ml and positive at 300 micrograms/ml 6 weeks after anaphylaxis, but negative at 300 micrograms/ml and positive at 1000 micrograms/ml 4 and 7 years after anaphylaxis. Prick tests were always negative, even with the maximum soluble concentration of CET, 200 mg/ml. Nonspecific reactions to intradermal tests at concentrations as high as 1000 micrograms/ml were examined with 20 kinds of penicillins and cephems in 51 healthy subjects without histories of drug allergies. Very few false positive reactions were observed, except in 5 out of 24 cases with cefotiam. Intradermal tests at 3000 micrograms/ml, however, frequently resulted in nonspecific reactions. We conclude that 1000 micrograms/ml, not 300 micrograms/ml solutions should be used for intradermal tests to prevent allergic reactions to the injection of antibiotics.     

Diagnosis and Immunotherapy of Mould Allergy

To determine reproducibility and the optimal way of expressing skin sensitivity, simultaneous skin prick tests (SPT) and intradermal tests (ICT) were performed on 25 mould-allergic patients. The patients had a well-documented history of allergy to Cladosporium and Alternaria and were tested with partially purified standardized extracts of these two mould species. Skin prick tests were carried out on the volar side of the forearm and intradermal tests on the backs of the patients. The skin tests were performed as titration using quadruplicate determinations of 10-fold allergen dilutions. The area of the skin reactions measured by planimetry were plotted in a log-log system as a function of the allergen concentration. The reproducibility (SD/mean area X 100%) of the ICTs was significantly higher than that of the SPTs (17% versus 29%). A very low reproducibility was found with wheal areas less than 5 mm2. The dose response curve of the SPT wheal area was steeper than that obtained with ICT, both concerning ICT wheal and flare. Increasing the allergen concentration with a factor 10 resulted in a doubling of the wheal area in SPT, in contrast to a factor 1.7 using ICT. The coefficient of correlation using linear regression on the dose response curve was always higher than 0.9 with SPT and ICT wheal, but significantly lower with ICT flare. Skin sensitivity was estimated as end-point and histamine equivalent reaction. No significant correlation between SPT and ICT end-point titration was found contrary to the histamine equivalent reaction.(ABSTRACT TRUNCATED AT 250 WORDS)     

Wheat allergy: diagnostic accuracy of skin prick and patch tests and specific IgE

BACKGROUND: Food allergy makes an important contribution to the pathogenesis of atopic eczema in infants. However, clinical data on cereal allergy are scanty. The objective was to study the relevance of patch testing, skin prick tests, and the concentration of wheat-specific IgE antibodies (CAP RAST) in correlation with oral wheat challenge in infants with suspected wheat allergy. In particular, we aimed to determine whether the patch test could increase the diagnostic accuracy in detecting wheat allergy. METHODS: The study material comprised 39 infants under the age of 2 years. Of these patients, 36 were suffering from atopic eczema and three had only gastrointestinal symptoms. The patients were subjected to a double-blind, placebo-controlled or open wheat challenge. Wheat-specific IgE was measured by CAP RAST, and skin prick and patch tests were performed. RESULTS: Of the total 39 wheat challenges, 22 (56%) were positive. Of the positive reactions, five involved immediate-type skin reactions over a period of 2 h from the commencement of the challenge. In 17 patients, delayed-onset reactions of eczematous or gastrointestinal type appeared. Of the infants with challenge-proven wheat allergy, 20% showed elevated IgE concentrations to wheat, 23% had a positive skin prick test, and 86% had a positive patch test for wheat. The specificities of CAP RAST, skin prick tests, and patch tests were 0.93, 1.00, and 0.35, respectively. CONCLUSIONS: Our study demonstrated that patch testing with cereals will significantly increase the probability of early detection of cereal allergy in infants with atopic eczema and is helpful in the planning of successful elimination diets before challenge. The specificity of the patch test was lower than that of other tests. Therefore, confirmation of the diagnosis with the elimination-challenge test is essential in patients with positive patch test results.     

Skin testing: a survey of allergists.

BACKGROUND: In the allergist's office, skin testing remains the central way to confirm allergic response. Although anecdotal data suggest widely varying practices in skin testing by allergists, the diversity and relative frequency of these practices have not been documented. OBJECTIVE: To determine the extent of the diversity in skin testing practices among allergists. METHODS: A questionnaire was sent via the Internet to all physician members and fellows of the American College of Allergy, Asthma and Immunology who practice in the United States. This survey explored choice of extract concentrations, skin test device, number and type of tests, method for interpretation and documentation of skin test results, and quality assurance procedures used. RESULTS: Overall, a significant degree of variability was reported with regard to number of skin tests performed, extract concentrations, skin test devices, interpretation and documentation of results, and quality assurance procedures. The average number of skin prick tests performed ranged from 5.09 (grasses) to 10.9 (trees), whereas the average number of intradermal tests performed ranged from 2.03 (grasses) to 5.6 (perennial). The allergen extract concentrations used for intradermal testing varied widely. Expressed as a dilution of the concentrated extracts, 20.8% use 1:100 dilutions, 10.3% use 1:500 dilutions, and 59.4% use 1:1,000 dilutions. Significant variability also occurred regarding devices and the technique with which the devices were used. Most clinicians (92.1%) used the most concentrated extract available for skin prick testing. For reporting the results of skin testing, 53.8% used a 0 to 4+ scale, and only 28.3% measured orthogonal diameters. Of those using a 0 to 4+ scale, two thirds related the results to the size of the histamine control. Quality assurance testing was reportedly performed by 61.2% of responders. However, less than 10% of responders used an objective test protocol for this purpose. CONCLUSIONS: This survey highlights some of the areas that allergists can improve on in the use and reporting of skin tests.