Efficacy of alternative tests for delayed-cyclic food hypersensitivity

Clinical Relevance and Advantages of Intradermal Test Results in 371 Patients with Allergic Rhinitis, Asthma and/or Otitis Media with Effusion

Background: We evaluated the value of positive intradermal dilution testing (IDT) after negative skin prick tests (SPT) by retrospectively determining allergy immunotherapy (AIT) outcomes. Methods: This private practice, cohort study compared the relative value of SPT vs. IDT in 371 adults and children with suspected manifestations of allergy: chronic allergic rhinitis (AR), asthma and/or chronic otitis media with effusion (OME). The primary outcome measure was symptom resolution following immunotherapy, as determined by symptom severity questionnaires completed by patients before and after AIT. Results: Positive IDT identified 193 (52%) patients who would not otherwise have been diagnosed. IDT detected 3.7-fold more allergens per patient than SPT (8.56 vs. 2.3; p < 0.01). Patients positive only on IDT responded to AIT equally well as those identifiable by SPT, independent of allergen sensitivity (67% by SPT vs. 62% by IDT; p = 0.69, not significantly different). Conclusion: Intradermal titration can identify patients who will benefit from allergy immunotherapy more accurately than SPT. Outcomes analysis in 371 patients shows that IDT doubled their chance of successful treatment with no greater risk of therapeutic failure. Positive IDT, following negative SPT, is clinically relevant and offers superior sensitivity over SPT for detecting allergens clinically relevant to diagnosis of AIT-responsive atopic disease.

Safety of intradermal skin tests for inhalants and foods: a prospective study

BACKGROUND

Intradermal skin testing is a useful allergy diagnostic tool. Although considered safe when properly performed, systemic reactions have been reported. This is the first large, prospective study to record and evaluate all systemic reactions from intradermal skin testing (IDT) to inhalant or food antigens.

METHODS

A 24-month prospective study by 40 physician practices, recording all IDT tests, including reactions, symptoms, severity, time after injection, and reaction treatments.

RESULTS

Eighty systemic reactions (22 major) occurred among 20,530 patients (878,583 wheals). Nine had epinephrine treatment, 4 were observed in an emergency department, and there were no hospitalizations or fatalities. The overall systemic reaction risk was 0.009%. The risk of having a major reaction was 0.003%, or 1 reaction per 933 patients.

CONCLUSION

Intradermal skin tests for inhalants or foods, when performed with appropriate precautions, have a safety profile comparable to skin prick tests.

Approaches to testing for food and chemical sensitivities

Testing for food and chemical sensitivities usually becomes necessary as part of the evaluation of otolaryngology patients who have chronic illness. The more complex the patient, and the more recalcitrant the problem is to treatment, the more likely it is that allergies, and especially food or chemical sensitivities, are involved in the pathogenesis of the illness. Failure to consider all major allergen contacts, including foods and chemicals, can lead to inadequate therapy. Similarly, failure to understand total allergic and oxidant load and the effects of chemical toxicity can lead to inappropriate or ineffective treatment. Clinically, food allergies occur in two different types: immediate, anaphylactic, fixed reactions and delayed, chronic, cyclic reactions. Different test methods have been developed for the two types. Fixed food allergies can be safely and efficiently detected by in vitro specific IgE or histamine release tests. Cyclic food allergies are best detected by either oral food challenges or by the IPDFT test. Choosing the best test for a particular patient requires a clear understanding of the two food allergy types and how their clinical presentations differ. Other tests for food allergies are compared and contrasted with these primary tests. Chemical sensitivity also occurs in two different clinical types: allergic, and toxic. True allergy to chemical haptens, either type I, IgE-mediated, or type IV, delayed hypersensitivity, occurs with significant frequency but is often unsuspected. Chemical toxicity can be caused by the aftereffects of an acute exposure or as a result of chronic, low-level exposure, but is even more frequently unsuspected and will not be diagnosed without a high index of suspicion. Both types of chemical sensitivity need to be addressed in any patients who have either a high allergen or chemical exposure load [105]. Either in vitro or in vivo tests can be used for chemical allergy detection; the advantages of each are outlined. Chemical toxicity screening tests are available and useful but do not detect all possible toxicants. Definitive toxic chemical tests usually require specialized laboratory facilities and expert consultation, for which possible sources are specified. The most important point in testing for food or chemical sensitivity is to be aware that food or chemical sensitivity can be contributing to a specific patient's clinical problems. Only then can appropriate investigations be undertaken to understand and then, perhaps, to intervene successfully in that illness.

The importance of glycerin-containing negative control tests in allergy research studies that use intradermal skin tests

OBJECTIVE

We sought to assess skin whealing with glycerin-containing control injections for intradermal skin tests.

DESIGN

Observational.

METHODS

Wheal sizes were measured at 0, 10, and 15 minutes after intradermal injection of 0.01 and 0.02 mL of phenolated normal saline and 0.5% and 5% concentrations of glycerin in the same quantity of phenolated saline.

RESULTS

Intradermal injection of 0.01 mL of phenolated saline produced an average 4.9-mm wheal, which expanded to 5.2 mm at 10 minutes and to 6.0 mm at 15 minutes. Intradermal injection of 0.02 mL of phenolated saline produced a 6.4-mm wheal, which expanded to 7.0 mm at 10 minutes and 8.0 mm at 15 minutes. The addition of glycerin produced proportionally larger wheals.

CONCLUSIONS

Because glycerin increases whealing beyond that with phenolated saline, skin tests containing glycerin must be compared with glycerin-containing negative controls. Intradermal skin tests that fail to compare findings in this manner contain an inherent methodologic flaw and are uninterpretable.

Allergy skin tests for inhalants and foods. Comparison of methods in common use

Many types of skin tests have evolved from Blackley's early scratch tests. This review highlights both the similarities between current skin tests and their differences. All current skin tests are capable of detecting allergic hypersensitivity, but the tests differ in their sensitivity, specificity, safety, reproducibility, and applications. Common factors in initial and final test doses, and in test dose increments, are identified. Test methods that quantitatively measure a range of allergen concentrations have diagnostic advantages in terms of safely detecting a wide range of allergic sensitivities. Failure to detect the full spectrum of allergic disease can lead to treatment failure; therefore, complete skin testing is desirable. This is especially important when dealing with exquisitely sensitive patients, such as many grass or ragweed sensitized patients, but is equally vital when evaluating low sensitivity patients, including many who are mold or food sensitive. Quantitation also improves test reproducibility, which is why it is used for antigen standardization. Finally, quantitation has advantages when used to initiate and escalate allergen immunotherapy. In vivo testing continues to evolve. New types of prick testing devices, and refinements of intradermal and patch test methods, continue to be reported. All allergists need to stay current with developments in vivo testing, so that they can offer their patients diagnosis that is appropriate to each individual situation.

Evolution to current otolaryngic allergy techniques

The evolution of current otolaryngic allergy techniques for the diagnosis and management of inhalant and food allergens is presented in this article. Skin titration, in vivo diagnostic techniques, and symptom-relieving immunotherapy are emphasized for the former sensitivities and oral challenge tests, skin titration, and elimination or rotary diets for the latter.

Association of otitis media with effusion and allergy as demonstrated by intradermal skin testing and eosinophil cationic protein levels in both middle ear effusions and mucosal biopsies

This study was performed to ascertain the role of allergy, as defined by skin testing and histochemical markers, in the pathogenesis of otitis media with effusion (OME). A historical perspective of allergy as it relates to OME is presented. The study included 89 patients: 48 with persistent effusion but no recent acute infection, 25 with purulent OME complicated by a superimposed infection, and 16 control subjects. All 89 patients had persistent effusion for more than 2 months and subsequently required the placement of tympanostomy tubes. Allergy was defined using the radioallergosorbent test (RAST), serum immunoglobulin E (IgE) levels, and skin tests. Allergies were present in 97% of the patients with nonacute OME. The relationship between allergy and OME was corroborated clinically in 89% of patients and was also substantiated by elevated levels of effusion eosinophil cationic protein (ECP) in 87.5% of OME patients. Histologically, polyclonal antibody staining for ECP demonstrated the presence of eosinophils in middle ear mucosal biopsy specimens. This study confirms that OME is a sign of allergic inflammation in the middle ear that is associated with an increase in eosinophils and a concomitant release of ECP into the effusion in individuals with allergy demonstrated by skin testing.

Levels of Eosinophil Cationic Protein and Myeloperoxidase from Chronic Middle Ear Effusion in Patients with Allergy and/or Acute Infection

BACKGROUND AND OBJECTIVE: Allergy may play a role in the middle ear inflammation that leads to otitis media with effusion. The purpose of this study was to determine whether an elevated mediator correlated with the patient's disease and thus could be used to differentiate allergy vs. infection as the cause of the middle ear inflammation.

METHODS: We evaluated 57 individuals with otitis media with effusion, 32 with persistent effusion but no recent acute infection, 14 with recent infection and purulent otitis media with effusion, and 11 healthy subjects. The mediator activity of eosinophils and neutrophils in effusion was studied in patients characterized as having allergy by positive intradermal skin test results and positive radioallergosorbent test results. Eosinophils were characterized by measurement of eosinophil cationic protein in the effusion. Neutrophils were characterized by measurement of myeloperoxidase in the effusion. The levels of eosinophil cationic protein and myeloperoxidase in patients with and without allergy were correlated to patient history.

RESULTS: Significantly elevated levels of both eosinophil cationic protein and myeloperoxidase indicated that inflammation in the ear of patients with otitis media with effusion was characterized by a pronounced involvement of both eosinophils and neutrophils. Eighty-nine percent of all patients with disease had allergy. A higher ratio of myeloperoxidase to eosinophil cationic protein in patients with purulent otitis media with effusion indicated that in patients with a superimposed acute infection, neutrophil activity was increased even further. The level of eosinophil cationic protein was elevated only during the effusion of patients with allergies as compared with controls ( p < 0.01). Among 29 cases of nonpurulent otitis media with effusion, 96.5% had allergic immune-mediated disease proved by skin testing, which was related clinically to their ear disease. Eighty-nine percent (89.6%) of these patients had eosinophil cationic protein levels greater than 10 μg/L.

CONCLUSION: Middle ear eosinophil cationic protein may be used as a marker of related allergy.

The presence of eosinophil cationic protein in middle ear effusion

Eosinophil cationic protein (ECP) is probably responsible for the underlying inflammatory mechanisms seen in asthma. It can be modulated in vivo by immunotherapy or steroids, with an appropriate reduction in symptoms of respiratory tract diseases. ECP is an identifiable mediator in additional target organs involved in allergic reactions, making it of potential interest in the study of otitis media with effusion. A qualitative prospective study was designed to discover the relationship of ECP and serum IgE in patients with middle ear effusion and allergy, as demonstrated by RAST and skin testing. The concentrations of ECP in the middle ear fluid from 23 consecutive patients with otitis media with effusion undergoing the placement of tympanostomy tubes ranged from 2 to 1248 micrograms (normal serum ECP, 5 to 15 micrograms), with 87% being abnormally elevated. There was no correlation between an individual's ear and serum levels of ECP (r = 0.1672; p = 0.6232), suggesting a more localized process. There was no relation between effusion ECP and serum IgE (p = 0.0040). ECP from middle ear effusion did correlate with a patient's having allergy, as confirmed by RAST and skin testing (p = 0.0095). Mechanisms involving immune mediated disease in the middle ear, of which the eosinophil may be one participant, are presented.

The intracutaneous progressive dilution multi-food test

Data have been published supporting the view that skin response is more valid and reliable than symptom provocation for interpretation of the intracutaneous provocative food test (IPFT). As such, an intracutaneous progressive dilution food test technique interpreted by skin response is now the standard IPFT technique taught at American Academy of Otolaryngic Allergy-sponsored courses. While this test technique is less time-consuming than the 5-day oral challenge food test of Rinkel, the 15- to 90-minute per test demand still presents a significant deterrant to widespread use. Here we present a time-efficient, multi-test technique that allows testing of three to seven foods at one time. The technique is not recommended for use on patients with a history of severe allergic reactions, such as asthma or angioedema, or for testing any food that by history may produce an anaphylactic reaction.