Why Do People Misdiagnose Themselves with Food Hypersensitivity? An Exploration of the Role of Biopsychosocial Factors

Up to 35% of people self-diagnose food allergy or intolerance (food hypersensitivity [FH]), or diagnose it in their child, and self-manage the condition rather than seek a clinical diagnosis. This is much higher than the latest FH prevalence rate, estimated to affect 2–5% of the general population. The actual prevalence rate may be underestimated due to the lack of diagnostic services; however, this can only account for a small proportion of the discrepancy because only a small percentage of self-reported FH can be clinically confirmed. Many people are therefore misdiagnosing their or their child’s symptoms as FH and needlessly removing foods from their or their child’s diet. There are a number of possible reasons for this misdiagnosis, which can be considered from a biopsychosocial perspective. Psychological factors include a confusion over the diagnosis, coincidental pairing of food and symptom, psychological or psychosomatic reactions, and taste aversions. There are also biological mechanisms that have not been fully considered in food allergy research that may be relevant, such as conditioning of the immune system or stress responses. A social context pertains to a greater awareness of FH due to media coverage and changes in food labelling laws. Any of these theories are plausible, but the research to date has a number of methodological issues. Most studies report on small self-selected samples recruited from clinics and there is a lack of general population data. Studies also tend to be cross-sectional, which does not allow cause and effect to be established. Future research needs to include longitudinal designs that incorporate qualitative elements to enable a detailed exploration of reasons why people self and misdiagnose FH.

Why Do People Misdiagnose Themselves with Food Hypersensitivity? An Exploration of the Role of Biopsychosocial Factors

Up to 35% of people self-diagnose food allergy or intolerance (food hypersensitivity [FH]), or diagnose it in their child, and self-manage the condition rather than seek a clinical diagnosis. This is much higher than the latest FH prevalence rate, estimated to affect 2–5% of the general population. The actual prevalence rate may be underestimated due to the lack of diagnostic services; however, this can only account for a small proportion of the discrepancy because only a small percentage of self-reported FH can be clinically confirmed. Many people are therefore misdiagnosing their or their child’s symptoms as FH and needlessly removing foods from their or their child’s diet. There are a number of possible reasons for this misdiagnosis, which can be considered from a biopsychosocial perspective. Psychological factors include a confusion over the diagnosis, coincidental pairing of food and symptom, psychological or psychosomatic reactions, and taste aversions. There are also biological mechanisms that have not been fully considered in food allergy research that may be relevant, such as conditioning of the immune system or stress responses. A social context pertains to a greater awareness of FH due to media coverage and changes in food labelling laws. Any of these theories are plausible, but the research to date has a number of methodological issues. Most studies report on small self-selected samples recruited from clinics and there is a lack of general population data. Studies also tend to be cross-sectional, which does not allow cause and effect to be established. Future research needs to include longitudinal designs that incorporate qualitative elements to enable a detailed exploration of reasons why people self and misdiagnose FH.

Situation-specific cognitive behavioural self-therapy for erroneously suspected allergy or intolerance to a food. A short self-assessment tool

The recall of personal experiences relevant to a claim of food allergy or food intolerance is assessed by a psychologically validated tool for evidence that the suspected food could have caused the adverse symptom suffered. The tool looks at recall from memory of a particular episode or episodes when food was followed by symptoms resulting in self-diagnosis of food allergy or intolerance compared to merely theoretical knowledge that such symptoms could arise after eating the food. If there is detailed recall of events that point to the food as a potential cause of the symptom and the symptom is sufficiently serious, the tool user is recommended to seek testing at an allergy clinic or by the appropriate specialist for a non-allergic sensitivity. If what is recalled does not support the logical possibility of a causal connection between eating that food and occurrence of the symptom, then the user of the tool is pointed to other potential sources of the problem. The user is also recommended to investigate remedies other than avoidance of the food that had been blamed.

No unique role for nausea attributed to eating a food in the recalled acquisition of sensory aversion for that food

Currently in the U.K., as in the U.S.A. 20 years ago, when students were asked to name a food that they did not like, more dislike for the food was attributed to nausea or vomiting after eating than to other gastrointestinal symptoms or to illness in other parts of the body. However, when members of the public first identified adverse symptoms and then attributed them to foods, and dislike for the food was first enquired about on a later occasion, there was no evidence for a unique role for a causal association with nausea in the human acquisition of food aversions. Furthermore, fear of the symptom was more prevalent than acquired sensory aversion when there was more precise recall of memories of the food being followed by nausea or vomiting and greater likelihood of there having been causal contingency rather than mere coincidence. Therefore, the more frequent invocation of nausea than of some other symptoms as the cause of a sensory aversion to a food may result from personal theory of the body, rather than from a veridically recalled occasion when nausea was contingent on eating the food---an event that must occur for aversion to arise from associative conditioning.

Psychological characteristics of people with perceived food intolerance in a community sample

In most adults who believe themselves to be food intolerant there is no objective supporting evidence. It has therefore been proposed that the misperception of intolerance to food is linked to psychiatric illness or personality disorder. This hypothesis was tested in a community-derived sample of individuals who attributed an adverse symptom to a type of food. A random mailing recruited 955 participants aged > or =18 years, of whom 232 perceived themselves to be food intolerant (PFI). All recruits were sent two questionnaires, the General Health Questionnaire-28 (GHQ-28) and the shortened version of the Eysenck Personality Questionnaire (EPQ-R). A total of 535 GHQ-28 and 518 EPQ-R forms were returned that were correctly completed, an overall response rate of 55%. For the subscales of the EPQ-R, neuroticism was greater in those with a PFI than those without. Women with a PFI were more extroverted than control women. For the GHQ-28 subscales, women with a PFI had significantly higher scores than control women on somatic symptoms, anxiety, insomnia, and severe depression. There was a greater percentage of psychiatric caseness among women with a PFI than among men with a PFI or control women. Nevertheless, this percentage was no greater than that reported among a reference sample derived from NHS and university staff. It is concluded that perceived food intolerance is associated with psychological distress in women with a PFI, and neurotic symptoms in both men and women with a PFI, but there is no greater prevalence of psychiatric disorder among women or men with a PFI than there is in some professional groups.