Provocation-neutralization: a two-part study. Part I. The intracutaneous provocative food test: a multi-center comparison study

Unproven Diagnostic Tests for Food Allergy

The gold standard for diagnosis of immunoglobulin E (IgE)-mediated food allergy remains the oral food challenge, with serum IgE testing and skin prick testing serving as acceptable alternatives. However, the increase in prevalence of food allergy (both physician diagnosed and patient suspected) has led patients to pursue a variety of other alternative diagnostic procedures for suspected food allergy, which are reviewed in this article. These procedures (IgG testing, electrodermal testing, cytotoxic testing, provocation/neutralization, and applied kinesiology) have largely been unproven and may lead to unnecessary elimination diets.

Nasal polyposis: Prevalence of positive food and inhalant skin tests

OBJECTIVES: To investigate the etiology of nasal polyps and its relationship to allergy. The prevalence of positive food and inhalant skin tests in patients with nasal polyps and nonatopic controls was compared.

STUDY DESIGN AND SETTING: Prospective controlled study in tertiary referral rhinology clinic.

RESULTS: Seventy percent (70%) of the patients with nasal polyps had positive skin tests to an average of four foodstuffs, compared to 34 percent of controls ( P = 0.006). Only 35 percent of the nasal polyp patients also had positive inhalant skin tests. Overall, the prevalence of positive inhalant skin tests was similar in the nasal polyp patients and controls.

CONCLUSIONS: These findings suggest that the positive skin tests to foods are not merely a reflection of the general atopic status of patients with nasal polyps. It may be that non-IgE-mediated hypersensitivities, such as to ingested foods, play a role on the basis of a significant number of patients with positive intradermal skin tests to foods.

SIGNIFICANCE: Evaluation of the allergic status of patients with polyposis is important. Dietary manipulation may be indicated, though its role needs further investigation.

EAACI food allergy and anaphylaxis guidelines: diagnosis and management of food allergy

Food allergy can result in considerable morbidity, impact negatively on quality of life, and prove costly in terms of medical care. These guidelines have been prepared by the European Academy of Allergy and Clinical Immunology's (EAACI) Guidelines for Food Allergy and Anaphylaxis Group, building on previous EAACI position papers on adverse reaction to foods and three recent systematic reviews on the epidemiology, diagnosis, and management of food allergy, and provide evidence-based recommendations for the diagnosis and management of food allergy. While the primary audience is allergists, this document is relevant for all other healthcare professionals, including primary care physicians, and pediatric and adult specialists, dieticians, pharmacists and paramedics. Our current understanding of the manifestations of food allergy, the role of diagnostic tests, and the effective management of patients of all ages with food allergy is presented. The acute management of non-life-threatening reactions is covered in these guidelines, but for guidance on the emergency management of anaphylaxis, readers are referred to the related EAACI Anaphylaxis Guidelines.

Potential non-immunoglobulin E-mediated food allergies: comparison of open challenge and double-blind placebo-controlled food challenge

OBJECTIVE

Comparison of open food challenge (OFC) with double-blind placebo-controlled food challenge (DBPCFC).

STUDY DESIGN

Prospective sequential randomized challenges.

METHODS

Twenty adults with chronic allergy symptoms and at least 1 positive intradermal food wheal response recorded symptoms during DBPCFC and OFC provoked using organic foods, normal portions, and normal food preparation. Acoustic Rhinometry and biochemical tests were done during DBPCFC.

RESULTS

All patients reacted to at least 1 food and to all challenges with the same food, with multiorgan symptoms in the nose, nervous system, throat, and lung. There was a correlation in the type and severity of symptoms (P = 0.015) for OFC and DBPCFC, and both were significantly (P < 0.01) more severe than placebo. Compared with DBPCFC, OFC sensitivity was 66%, and positive predictive value was 89%.

CONCLUSION

This is the first study showing both concordance of OFC and DBPCFC and also that intradermal tests can identify reactive foods that can be verified by DBPCFC. Because most tests for IgE-mediated food allergy were negative, observed reactions were probably non-IgE mediated.

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.

Unproved diagnostic and therapeutic approaches to food allergy and intolerance

PURPOSE OF REVIEW

Alternative and complementary medicine approaches to allergic disorders are commonly used by patients. Not all have been subjected to experimental analysis to support or refute their validity in the armamentarium of a practitioner. This review covers some of the most common unproved alternative or complementary approaches to diagnosis and therapy that we see in use by patients. These include the use of specific IgG to foods accompanied by rotary diets, provocation-neutralization testing and therapy, applied kinesiology followed by acupressure or acupuncture, and changes in cell size upon in-vitro exposure of leukocytes to food extract (using automated assays going under various trade names) followed by elimination diets or rotary diets.

RECENT FINDINGS

There continues to be a dearth of well performed studies investigating these approaches in the literature, but many testimonials have been posted on websites of practitioners using these methods attesting to their effectiveness. Several recent studies have refuted the use of applied kinesiology and provocation-neutralization in diagnosis. The placebo effect must not be overlooked as a potentially important factor in some approaches.

SUMMARY

There have been no studies supporting the use of these techniques, and several have refuted their utility. A beneficial placebo effect may be responsible for the perceived clinical effectiveness in many cases of food intolerance.

Prevalence of heat shock protein in patients with Meniere's disease and allergy

OBJECTIVE

The study purpose was to investigate the prevalence of elevated heat shock protein 70 (HSP-70) in patients with Meniere's disease who have milk allergy compared with those who are not allergic to milk.

METHODS

Fifty-five patients with Meniere's disease and allergy in whom milk allergy had been confirmed by intradermal progressive dilutional food testing or skin testing to milk antigen were included. Blood serum was tested for HSP-70 elevation with a Western blot assay using bovine renal extract. The 29 women and 26 men ranged in age from 29 to 76 years (mean age 52.8 years). Forty percent of the patients had bilateral Meniere's disease.

RESULTS

Overall prevalence of HSP-70 elevation was 29.1%. This was higher in bilateral patients (50%) than unilateral patients (15%) (P <or= 0.007). The effect was based primarily on elevated HSP-70 in bilateral (62.5%) and unilateral (7.7%) patients in those with no milk allergy (P <or= 0.006). The prevalence of HSP-70 elevation was actually lower in those with milk allergy (19.2%) than in those with no milk allergy (37.9%). This difference was statistically significant only in the subset of patients who were <50 years old (0% vs 33.3%, respectively; P <or= 0.04).

CONCLUSIONS

We found no relationship between the presence of antibodies to HSP-70 and allergy to milk. The significance of elevated HSP-70 in patients with Meniere's disease has yet to be defined.

Treatment of delayed food allergy based on specific immunoglobulin G RAST testing

This preliminary, descriptive study after extensive clinical experience demonstrates specific IgG food RASTs done in 114 consecutive patients with strong positive histories for delayed food allergy. Elimination of the positive foods was the sole means of treatment. The symptoms leading to the test are detailed, and the method of workup is reviewed. The overall results demonstrated a 71% success rate for all symptoms achieving at least a 75% improvement level. Of particular interest was the group of patients with chronic, disabling symptoms, unresponsive to other intensive treatments. Whereas 70% obtained 75% or more improvement, 20% of these patients obtained 100% relief.

Biological effects of low-level environmental agents

We compare three similar but different biological effects: provocation-neutralisation treatment of non-antibody-mediated hypersensitivities, hormesis and low-level effects in radiation biology. All three have not yet been fully explained but share some common and interesting properties: non-linear concentration dependence, typical stress pattern and typical immune response. We try to make a generalisation of the three phenomena in terms of the informational properties of the low concentrations, and imply the possible common mechanism.

Nasal polyposis: role of subclinical delayed food hypersensitivity

Nasal polyposis is a common problem in otolaryngology. The cause remains unclear, and treatment with medication and surgery is often unsatisfactory. We present our controlled study, which suggests a strong association between food allergy and nasal polyposis. The study was conducted in 2 parts. A postal survey of 900 patients with nasal polyps showed 53 respondents (5.9%) had a known food allergy. In the prospective study, 80 nasal polyp patients and 36 control subjects completed intradermal tests for food allergy. Sixty-five nasal polyp patients (81%) and 4 control subjects (11%) had positive intradermal food test results. This is highly significant. We believe that food allergy may play a significant role in the pathogenesis of nasal polyposis and should be further studied.

Dysphonia and delayed food allergy: a provocation/neutralization study with strobovideolaryngoscopy

In most cases the cause of intermittent dysphonia remains undiagnosed. This descriptive study explores the relationship between this problem and delayed food allergy. Double-blind intradermal provocation/neutralization skin tests to food antigens were used to do 12 tests in 10 subjects with food allergies. Strobovideolaryngoscopy was used to document changes in the vocal folds and in the quality of the voice. Double-blind measurements of signs and symptoms, digital audio recordings of the voice for perceptual and acoustic analysis, and aerodynamic laryngeal airflow and resistance measurements were done. The cause of dysphonia appeared to be associated with an increase in thick mucus production and irregular and asymmetric glottic edge edema of the vocal folds. Elimination of the positive specific foods resulted in cessation of dysphonia in all the test subjects. Statistical analysis was not done because of the lack of parametric data for paired analysis, lack of sufficient data points for resampling statistics, and the small sample size.

Intradermal testing for food and chemical sensitivities: a double-blind controlled study

BACKGROUND

Confirming adverse reactions to foods and chemicals is fundamental in providing a basis for diagnosis and treatment of patients with reported environmental sensitivities. Provocation-neutralization testing is widely used in this respect but has not been thoroughly evaluated, therefore remaining a controversial and unproven technique.

OBJECTIVE

This study investigated the validity of intradermal testing for evaluation of reported adverse reactions to a variety of incidents within the patient population at the Nova Scotia Environmental Health Centre.

METHODS

A total of 132 people who were referred to the Nova Scotia Environmental Health Centre, a dedicated government-funded research and treatment facility for suspected environmental sensitivities, were tested by the technique of provocation-neutralization by the guidelines set out by the American Academy of Environmental Medicine. A panel of 13 foods, 9 chemicals, and 4 placebos (normal saline solution) was evaluated in a double-blind, randomized study. Symptoms and skin reactions were recorded, and response rates were determined for all substances, including saline solution injections.

RESULTS

Seventy percent of the patients reported symptoms to 1 or more of the 4 saline solution injections. In comparison, 15% of patients experienced a skin reaction (wheal) to 1 or more injections of saline solution. Only 5% of individuals experienced a wheal to more than 1 saline solution injection, although 40% of the patients reported symptoms to more than 1 saline injection. Patients who experienced 1 or more reactions (wheal or symptoms) to saline solution were more reactive to injected allergens, on average reacting to 67% of active substances. Patients who experienced no reaction to the saline solution did experience a reaction to 48% of injected substances on average. Reaction by symptoms to foods, chemicals, and normal saline solution showed a random pattern, although wheal reactions showed a distinct pattern. Subsequent observations have indicated that experiencing no reaction to previous saline solution injections does not accurately predict response to saline solution in later testing. Some individuals who did not experience a reaction to saline solution in an initial screening later experienced a reaction to saline solution during further testing.

CONCLUSIONS

Provocation of symptoms in usual testing conditions is not a useful tool for discriminating between reactions to saline solution and reactions to specific chemicals or foods. Skin response alone may be a more reliable indicator and will require cross-validation with other tests, such as oral and inhalation challenges and comparison with a control population. Heightened sensitivity and chaotic responses may be a feature of chemical sensitivity. Meanwhile, the results of provocation-neutralization testing, using symptoms alone as an indicator of neutralization, should not be used as a basis for clinical intervention.

An unproven technique with potentially fatal outcome: provocation/neutralization in a patient with systemic mastocytosis

OBJECTIVE

To describe the risks associated with use of an unproven technique, provocation/neutralization, in diagnosis and treatment of a putative "food allergy" in a patient with systemic mastocytosis.

METHODS

A case report of a 68-year-old woman with mastocytosis is reported. The patient was interviewed, examined, and all medical records were reviewed. Photos were taken, and skin and colonic biopsies were performed.

RESULTS

The patient was previously diagnosed with urticaria pigmentosa but also had significant diarrhea that was well-controlled by oral cromolyn sodium. She saw a physician who practiced provocation/neutralization and was told that food allergies were the cause of her gastrointestinal symptoms. She was placed on "neutralizing" injections of milk and wheat, but experienced flushing, palpitations, and lightheadedness with syncope upon injections into her thigh, which is a skin area highly involved by visible lesions of cutaneous mastocytosis. Later evaluation revealed increased numbers of mast cells in her colonic mucosa as well as confirmation of cutaneous mastocytosis.

CONCLUSIONS

The patient's previous history of urticaria pigmentosa, orally communicated by the patient, documented in medical records, and easily visible on physical examination, was discounted by a practitioner of an alternative and unproven medical treatment, provocation/neutralization. She subsequently had potentially life-threatening reactions to "provocative" skin testing and "neutralizing" injections. Patients with systemic mastocytosis are at risk for significant mast cell mediator release during immunotherapy, conventional or alternative.

Allergy for the laryngologist

Allergic disease can affect any portion of the respiratory tract, including the larynx, trachea, bronchial tree, nasal cavity, paranasal sinuses, nasopharynx, and pharynx. This review evaluates laryngeal manifestations of allergic disease and the impact of allergic mechanisms in disorders, within the scope of laryngology.

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.

Multiple chemical sensitivity multiorgan dysesthesia, multiple symptom complex, and multiple confusion: problems in diagnosing the patient presenting with unexplained multisystemic symptoms

Patients are presenting in increasing numbers with multiorgan symptoms allegedly resulting from exposure to environmental chemicals. Among the symptoms expressed by patients with alleged multiple chemical sensitivities (MCS) are profound fatigue, mental confusion, myalgia, depression, anxiety, dizziness, headache, insomnia, loss of appetite, and numbness of the extremities, all in the absence of objective physical signs. Diagnostic criteria to assess the effects of environmental agents on organ systems are sorely needed because patients with MCS often have no tissue pathology or physiological abnormalities, but often do have diagnosable psychiatric illnesses. In treating patients with MCS, the physician should first perform a complete history and physical examination, including a comprehensive evaluation of chemical exposure. If the findings strongly suggest the presence of disease related to particular organ systems, further diagnostic evaluation should be undertaken. If abnormal findings are absent, psychiatric advice may be useful. The physician should keep an open mind about MCS but must also remember that a cause-effect relationship between exposure to multiple chemicals and symptoms has not been established.

Science or flat earthers? The clinical ecologist replies

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Use of electrocochleography to monitor antigenic challenge in Menière's disease

Allergy has been reported as a cause of Menière's disease. King et al. have established the validity of the provocative food test (PFT) for the diagnosis of food allergy. When the PFT is used to test patients with Menière's disease, the test is considered positive if the patient develops aural fullness, hearing loss, increased tinnitus, or dizziness during challenge with the offending food and relief of these symptoms during neutralization. Ferraro et al. have shown that electrocochleography (ECoG) provides an objective indication of subjective symptoms in Menière's disease by demonstrating an increased SP/AP amplitude ratio when the symptoms of aural fullness and hearing loss are present. We present several patients with Menière's disease in whom measurement of the SP/AP amplitude ratio was compared with symptom production during antigenic challenge and neutralization.

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.