Objective evaluation of immediate reading skin prick test applying image planimetric and reaction thermometry analyses.

The skin prick test is used to diagnose patients' sensitization to antigens through a mediated IgE response. It is a practical and quick exam, but its diagnosis depends on instruments for measuring the allergic response and observer's interpretation. The conventional method for inferring about the allergic reaction is performed from the dimensions of the wheals, which are measured using a ruler or a caliper. To make this diagnosis less dependent on human interpretation, the present study proposes two alternative methods to infer about the allergic reaction: computational determination of the wheal area and a study of the temperature variation of the patient's skin in the puncture region. For this purpose, prick test using histamine was performed on 20 patients randomly selected. The areas were determined by the conventional method using the dimensions of the wheals measured with a digital caliper 30 min after the puncture. The wheal areas were also determined by a Python algorithm using photographs of the puncture region obtained with a smartphone. A variable named circularity deviation was also determined for each analyzed wheal. The temperature variation was monitored using an infrared temperature sensor, which collected temperature data for 30 min. All results were statistically compared or correlated. The results showed that the computational method to infer the wheal areas did not differ significantly from the areas determined by the conventional method (p-value = 0.07585). Temperature monitoring revealed that there was a consistent temperature increase in the first minutes after the puncture, followed by stabilization, so that the data could be adjusted by a logistic equation (R2 = 0.96). This adjustment showed that the optimal time to measure the temperature is 800 s after the puncture, when the temperature stabilization occurs. The results have also shown that this temperature stabilization has a significant positive correlation with wheal area (p-value = 0.0015). Thus, we concluded that the proposed computational method is more accurate to infer the wheal area when compared to the traditional method, and that the temperature may be used as an alternative parameter to infer about the allergic reaction.

Beyond flat weals: validation of a three-dimensional imaging technology that will improve skin allergy research.

Skin-prick tests (SPTs) are a standard way to test for sensitizations to allergens, but to date, techniques that allow for high-quality measurements of the resulting weals for research purposes are lacking. In this study, we assessed a new three-dimensional (3D) imaging technology for its accuracy and consistency. We found that this new technology showed very little intraoperator and interoperator variation for repeated measurements of a model of known area by each of two operators. We also found that repeated measurements of the same object over 4 months showed virtually no variation. Finally, 3D imaging was superior to traditional ruler measurements for assessing SPT reactions to histamine and allergen. For high-quality measurements of SPT reactions, 3D imaging is accurate, consistent and reliable.

Computer-aided skin prick test.

The interpretation of the skin prick test is subject to inter-observer variation. To remove this variation, a computerized procedure for the skin prick test is suggested. Instead of manually measuring the emerging wheals, a series of photographs is automatically taken of the forearm. The photographs thus taken are then analyzed with a digital image processing algorithm to give the measurement results. The computerized test has the added benefit of being able to produce a time series for the wheal size. This makes it possible to see the onset time of the reaction in addition to the size of the wheal. Preliminary feasibility test suggests that the simple setup described in this letter is able to perform the skin prick test automatically and to show the kinetic behaviour of the wheal. The main challenges with the test setup are related to illumination and wheal detection algorithms.

Use of intradermal dilutional testing and skin prick testing: clinical relevance and cost efficiency.

OBJECTIVES/HYPOTHESIS: The objective was to determine the agreement of the positive results from a multiple skin prick test (SPT) device with the ability to determine a definable endpoint through intradermal dilutional testing (IDT) to compare semiquantitatively the degree of positivity of SPT results with quantitative results from IDT and to analyze the cost of immunotherapy based on SPT compared with IDT guided by SPT. STUDY DESIGN: Retrospective review of clinical data (random accrual). METHODS: One hundred thirty-four patients underwent allergy screening using a multiple SPT device. Antigens testing positive by skin prick device were tested using IDT on a separate day. Antigens testing negative by SPT were not evaluated by IDT. Regional allergy testing practice patterns were determined, and a cost analysis using Medicare rates was performed RESULTS: There was good agreement between an antigen testing positive by SPT and the determination of a definable endpoint (93.33%, n = 1,334 antigens). The degree of positivity from the SPT correlated poorly with the final endpoint concentration (r = 0.40, P < .0001). Blended testing techniques were similar in cost when compared with several commonly used allergy testing protocols. CONCLUSIONS: Antigens which show reactivity to a multiple SPT device usually have a treatable endpoint that is independent of the degree of positivity of the SPT result. IDT is an important step in the determination of the strongest starting dose of immunotherapy that may be safely administered. Initiating immunotherapy in this manner may potentially create significant health care savings by shortening the time required for a patient to reach their individual maximally tolerated dose. The use of a relatively large screening panel is cost effective and does not increase the average number of antigens treated by immunotherapy. Blended allergy testing techniques that include IDT in their protocol are comparable in cost with commonly used allergy testing protocols.

Accidental needle sticks, the Occupational Safety and Health Administration, and the fallacy of public policy.

BACKGROUND: Current Occupational Safety and Health Administration (OSHA) guidelines mandate the use of safety needles when allergy injections are given. Safety needles for intradermal testing remain optional. Whether safety needles reduce the number of accidental needle sticks (ANSs) in the outpatient setting has yet to be proven. OBJECTIVE: To determine the rate of ANSs with new (safety) needles vs old needles used in allergy immunotherapy and intradermal testing. METHODS: Allergy practices from 22 states were surveyed by e-mail. RESULTS: Seventy practices (28%) responded to the survey. Twice as many ANSs occurred in practices giving immunotherapy when using new needles vs old needles (P < .01). The rate of ANSs was roughly the same for intradermal testing with new needles vs old needles. CONCLUSIONS: These findings further question whether OSHA's guidelines for safety needle use in outpatient practice need revision and if allergy practices might be excluded from the requirement to use safety needles.

Cynomolgus monkeys (Macaca fascicularis) in preclinical immune function safety testing: development of a delayed-type hypersensitivity procedure.

A delayed-type hypersensitivity (DTH) test commonly used for humans was adapted for use with cynomolgus monkeys (Macaca fascicularis). Pilot experiments showed naive animals had poor response rates and inconsistent reactivity to the antigens. In an exploratory phase, it was determined that monkeys could be experimentally sensitized by immunization with commercially available antigens. Animals were then sensitized with various concentrations of diphtheria and tetanus toxoids, Candida, and Trichophyton in the dose-response phase. Antigens were injected intradermally (i.d.) 3 times over a 7-day period and monkeys were tested 14 days after the last injection. Responses were measured 24, 48, and 72 h post-challenge, with skin biopsies taken from two animals per group at the 24 h interval. Optimal concentrations were 1.2 Lf diphtheria, 6 Lf tetanus, 1000 PNU Candida, and 1000 PNU Trichophyton. These concentrations produced the best balance between DTH responses, homogeneity of dermal mononuclear cell infiltrate and lowest frequency of undesirable skin reactions. Positive responses were seen at 24 and 48 h post-challenge and were waning by 72 h. DTH responses were inhibited by topical corticosteroids. The final phase of these studies assessed whether sensitization of naive animals could be achieved using subcutaneous (s.c.) administration of the optimal antigen concentrations. Comparable responses to i.d. sensitization were obtained and skin sores did not develop at injection sites. These studies show that the DTH test adapted to monkeys was reproducible, minimally invasive, did not require sacrifice of the test animal, allowed repeated measurements and paralleled the reactions observed in humans.

Prilotest, an innovative disposable skin puncture test: qualitative aspects.

Prilotest is a new disposable skin puncture test that has been recently produced and marketed by Laboratorio Farmaceutico Lofarma, Milan-Italy. The tip of the device is submerged in a well containing the allergen extract. As a result, the product is ready for use and there is no longer a need to place a drop of the allergen extract on the skin beforehand. Thus, the diagnostic procedure is simplified, the test offers excellent reproducibility. We made a comparative test of the reproducibility of the new method and Pepys' modified prick test on thirty patients (10 sensitized to Grass pollen, 10 to Pellitory pollen, and 10 to house dust mites); each test was repeated eight times. We also evaluated the specificity and sensitivity of the new method in 39 different allergic patients (13 sensitized to Grass pollen, 13 to Pellitory pollen, and 13 to house dust mites) and in 39 healthy subjects. The results show that the new method has a significantly higher level of reproducibility than Pepys' modified prick test. Furthermore, the reproducibility obtained is higher than results reported in literature for various standardized prick test methods. The sensitivity and specificity of the new method was excellent.

Quantitative skin prick tests and specific IgE (CAP System) for D. pteronissynus--correlation of results in a paediatric population.

The CAP System compared with RAST has a greater sensitivity, with the same specificity, as well as an excellent correlation with skin prick tests (SPT), as documented by others. Standardization of SPT is essential for routine and investigational purposes. We used a standardized lancet (DHS), and the methodology of reading the SPT was a computerized digitalized graphics tablet coupled to an IBM-PC AT using CAD software, expressing the result as wheal areas with cut off +/- at 7 mm2. The method is precise and reproducible with a mean coefficient of variation (cv) intratester--T1: 3.1%, T2: 3.5% and a cv intertester: 2.93%. We compare the results of SPT of two different allergen extracts for Dermatophagoides Pteronissynus (DPt) (Bencard; Merck/Allergo-Pharma, standardized in SBU) and correlate them with specific IgE, in 122 patients, 72 males and 50 females, aged 3 to 19 years. The results between the extracts and the results of specific IgE obtained by CAP System with each of the extracts, were correlated. 34 patients were considered to be non atopic. 88 patients showed at least one positive result with one test, being those used to correlate the positive results.... The results showed good correlations for quantitative SPT between Bencard and Merck/Allergo-Pharma, as well as for the capacity of eliciting positive results. When SPT were compared to specific IgE as +/- and as quantitative results, there were good correlation for Bencard/CAP and Merck/CAP. The results obtained suggest that CAP can be used to validate allergen extracts of DPt and that studies with other extract are advisable.

["Allergy testing" with "Dr. Voll electroacupuncture"]. / "Allergiestestung" mit der "Elektroakupunktur nach Dr. Voll".

Electroacupuncture according to Dr. Voll (EAV) is one of the numerous unconventional methods propagated for allergy testing in Germany. From an experimental examination for "drug testing" of this method, it can be concluded that EAV is unsuitable for any form of allergy testing.

Prediction of pulmonary immunodeficiency in chronic bronchitis by cutaneous hypoergy to multitest.

Multitest (Pasteur Mérieux) is a plastic disposable device used to assess delayed cutaneous hypersensitivity (DCH) to seven antigens. Hypoergy to Multitest is believed to reflect a status of compromised cell-mediated immunity. Among the many possible pathogenic factors of chronic bronchitis, immunodepression has been little investigated. Indeed, whether lower immunodefence is the cause or the consequence of chronic bronchitis is still a subject of debate. The aim of the study was to evaluate DCH in a large group of patients with chronic obstructive pulmonary disease (COPD) and in a control group, in order to relate DCH (expressed as score, mm) to clinical and functional impairment. One hundred patients with COPD in stable conditions and not undergoing treatment with immunomodulating drugs (mean age, yr, M +/- SD: 66.1 +/- 6.5) and 40 normal controls in the same age range were admitted to the study. Evaluated parameters were: symptoms scores, physical examination, lung function tests and Multitest. Fifty-three percent of the COPD patients were hypoergic compared with 14% of controls. The Multitest score was 10 +/- 10 (mm M +/- SD) in COPD compared with 17 +/- 9 in controls. The Multitest score was significantly related to age (r = -0.45) in the control group, but not in COPD patients. DCH to only three of the seven antigens may predict a response to Multitest, with a sensitivity of 90%.(ABSTRACT TRUNCATED AT 250 WORDS)

Utilidad del multitest en el diagnóstico de las enfermedades alérgicas / Multitest usefulness in the allergenic diseases diagnosis

Se utilizaron al azar dos grupos de 30 pacientes con diagnóstico de rinitis y/o asma alérgicas, para conocer la sensibilidad y especificidad del multitest en el diagnóstico de tales enfermedades, comparado con las pruebas intradérmicas y Rast, a siete alergenos más comunes de esta zona, y el grado de aceptación de los pacientes. Al evaluar la preferencia del paciente, la mayoría prefirió multitest porque les dolió menos (p=0.000001); sin embargo, la prueba intradérmica demostró tener mayor sensibilidad y especificidad corroborando por Rast que multitest cuando se evaluaron polvo (P=000001) y dermatophagoides farinae (P>0.01), aunque no hubo diferencias con los otros alergenos y el testigo. Nosotros concluimos que el multiest es un método de diagnóstico útil, seguro y confiable para evaluar la respuesta alérgica en los pacientes; sin embargo, cuando el cuadro clínico sea sugestivo de alergia y el mutitest sea negativo, deberán practicarse pruebas intradérmicas.

[Use of the Sevac Immunoskintest kit in children]. / Pouzití soupravy Imunoskintest Sevac u detí.

The Immunoskintest SEVAC is a kit of antigens for skin tests to evaluate the state of cellular immunity. By means of this kit 591 children from birth to 15 years were examined: the children suffered from acute diseases of the CNS, respiratory diseases incl. relapsing ones, a malignant tumour, haematological disease, and there were children who were Mantoux II negative and healthy children from children's homes. The value of the index of the skin test was referred to the child's age and sex; the lowest values were recorded in children with immunosuppressive therapy and the highest values of the skin test were found in healthy children and those with acute disease; boys had higher values than girls. In none of the children undesirable side-reaction were recorded after administration of the antigens.

In vivo determination of cell mediated immune response in diabetic patients using a multiple intradermal antigen dispenser.

The in vivo cell mediated immune response using a multiple intradermal antigen dispenser (Multitest) was evaluated in 99 diabetic patients (24 Type I and 75 Type II) and in 50 age matched normal subjects. Seven different antigens (tetanus, diphteria, streptococcus, tubercoline, candida, trichophyton, proteus and a glycerine control) were applied in the forearm and the induration for the antigens tested was measured 48 hours later. A score was calculated adding the arithmetic means obtained with each single antigen. Overall we did not find major differences between diabetic patients and controls except Type I patients of shorter duration (less than 5 years) having a reduced response (p less than 0.05) and both Type I and Type II patients showing an elevated response to candida antigen (p less than 0.001). No correlation was found between the intradermal response and metabolic control. As the intradermal test is a model for delayed type of hypersensitivity, these data suggest that the in vivo lymphocyte to lymphocyte cooperation in patients with long standing diabetes is not impaired.

[Evaluation of the delayed hypersensitivity response by the Multitest-IMC. Multicenter study for the definition of reference values in a sample population]. / Valutazione della risposta di ipersensibilità ritardata mediante Multitest-IMC. Studio multicentrico per la definizione di valori di riferimento in una popolazione campione.

The latest investigations in the field of clinical immunology have proposed ways of assessing immunological efficiency that have also been used to identify patients most susceptible to infectious complications. The assessment of delayed hypersensitivity response (DHR) using anamnestic antigens is currently the most common method. The results of a polycentric study are presented. The study was conducted on a group of healthy subjects from various Italian regions divided into three age classes. Positive responses to the MT were noted in 96.4% of the population studied. The incidence of energy was statistically higher among females than males, while the mean response to the MT expressed in millimetres was statistically higher in males. Though 7 antigens were administered, the responsive population reacted on average to 3. The highest incidence of positive responses was to Candida, with Trichophyton responsible for the fewest.

The precision of intracutaneous skin test with timothy pollen allergen preparation using two different techniques.

The precision of two intracutaneous skin test techniques was investigated by testing three grass pollen-sensitive patients. Twenty tests were performed on the back of each patient with each of two techniques. One method used a glass syringe with a 26 G precision needle attached to micrometer equipment. The other method used a disposable 1-mL plastic syringe with a disposable 20 G needle. The tests were arranged in five rows. Each row consisted of two pairs of tests on each side of the spine. Each pair was considered as duplicate tests at the same site. The two methods were tested on either side of the back. No difference in precision between the techniques was found. The analysis revealed differences in skin reactivity between different areas of the back of individual patients but without a common pattern between patients. These differences, therefore, will not influence test results if several patients are included in the investigation, eg, of the relative potency of allergenic extracts and the allocation of test sites is consistent. The variation found, however, will influence comparisons within the same patient, but in an unpredictable way.