A Histamine-Free Diet Is Helpful for Treatment of Adult Patients with Chronic Spontaneous Urticaria

The Western Diet and Atopic Dermatitis: The Potential Role of Nutrients, Contaminants, and Additives in Dysbiosis and Epithelial Barrier Dysfunction

Atopic dermatitis (AD) is a chronic inflammatory skin disorder influenced by both genetic and environmental factors, collectively termed the exposome. Among these determinants, diet emerges as a pivotal component, with diverse nutrients, contaminants, and additives shaping immune responses, microbiota composition, and systemic inflammatory status. This literature review aimed to elucidate the interplay between dietary factors and skin dysbiosis in AD, providing insights into how these interactions may impact disease susceptibility and progression. A comprehensive search of PubMed and Scopus was conducted using relevant keywords and medical subject headings (MeSH). Studies published in English within the past 25 years were included, encompassing in vitro, in vivo, and ex vivo research, as well as reviews. Priority was given to frequently cited articles, reflecting significant contributions to current understanding. Findings suggest that dietary habits influence AD by modulating both gut and skin microbiota, immune pathways, and inflammatory processes. These insights underscore the importance of considering diet within a broader exposome framework, paving the way for targeted interventions to improve AD management. Further research is needed to clarify the mechanisms and optimize nutritional strategies, potentially informing preventive and therapeutic approaches for AD.

Comorbidity of Histamine Intolerance and Polyvalent Allergy: A Case Report and Literature Review

Background/Objectives: Histamine intolerance is becoming a critical medical problem across numerous clinical specialties, due to the absence of a standardized diagnostic and therapeutic strategy to manage patients with a suspicion of or diagnosis of this condition. Histamine intolerance is a type of non-immune food hypersensitivity, characterized by heterogenous etiologies and a very broad range of symptoms. The condition is the result of an imbalance between the amount of histamine accumulated within the body and the body's systemic ability to degrade it. In regard to the diagnostics of histamine intolerance, the need to preliminarily exclude other potential conditions associated with increased histamine levels in the blood has been highlighted. The co-occurrence of allergies and histamine intolerance is not uncommon, and the similarity of the clinical manifestations can lead to diagnostic, as well as therapeutic, difficulties. This paper details the diagnostic and clinical workflow for a patient with histamine intolerance and polyvalent allergy comorbidity, with the aim being to help outline a protocol that may be helpful to clinicians managing patients with histamine intolerance. Case Presentation: This article presents the case of a 30-year-old patient with a polyvalent allergy and multimorbidity (allergic rhinitis, asthma, a food allergy, and eosinophilic esophagitis), with comorbid histamine intolerance. Due to the violent and severe symptoms, including facial erythema, urticaria, pruritus, abdominal pain, and tachycardia, experienced after meals, the patient received intramuscular epinephrine injections three times a week. The diagnostic protocol and the course of therapeutic management are presented. Conclusions: The diagnosis of histamine intolerance is difficult due to the high variability and heterogeneity of clinical symptoms in individual patients. Many studies on the issue recommend ruling out an allergic background in terms of the complaint. However, the possibility of the symptoms of an IgE-dependent allergy overlapping with those of histamine intolerance should be taken into account in every case. This is particularly important in patients presenting with an atypical and severe course of allergic diseases. The clinical case presented herein may be helpful for the daily practice of allergologists and physicians with other specialties, as an example of multimorbidity with both allergic and non-allergic backgrounds.

Study Protocol for a Prospective, Unicentric, Double-Blind, Randomized, and Placebo-Controlled Trial on the Efficacy of a Low-Histamine Diet and DAO Enzyme Supplementation in Patients with Histamine Intolerance

BACKGROUND/OBJECTIVES

Histamine intolerance is primarily caused by a deficiency in the diamine oxidase (DAO) enzyme at the intestinal level. The reduced histamine degradation in the gut leads to its accumulation in plasma, thereby causing multiple clinical manifestations, such as urticaria, diarrhea, headache, dyspnea, or tachycardia, among others. The dietary management of this food intolerance consists of the follow-up of a low-histamine diet, often combined with DAO supplementation. To date, around twenty studies have investigated the effectiveness of these dietary strategies in reducing the frequency and/or intensity of symptoms, with promising results. However, the limitations of these studies (small patient cohort, lack of control group, and short dietary intervention periods) highlight the need for more ambitiously designed research. Therefore, the main objective of this prospective, unicentric, double-blind, randomized, and placebo-controlled trial is to evaluate the efficacy of a low-histamine diet and/or DAO supplementation over a three-month period in improving symptoms of histamine intolerance. Additionally, the impacts of these dietary strategies on the intestinal microbiota composition, urinary profile of histamine metabolites, serum DAO activity, and plasma histamine levels will be assessed throughout the intervention.

METHODS

The trial will enroll 400 patients who will be randomly assigned to one of two groups: the intervention group, which will follow a low-histamine diet, or the control group, which will maintain their habitual dietary habits. Within each of these groups, participants will be further divided into four subgroups to receive either exogenous DAO enzyme supplementation (from porcine or plant sources, with the latter administered at two different dosages) or a placebo. Therefore, a total of eight distinct intervention groups will be considered. The comparison of these groups will allow the evaluation of the individual effects of the low-histamine diet or DAO enzyme supplementation, as well as their possible synergistic effect.

RESULTS

The results of this study should help to improve dietary recommendations for histamine-intolerant patients and ultimately enhance their quality of life.

Naturally Occurring Food Chemical Components and Extraintestinal and Gastrointestinal Symptoms in Adults: A Systematic Review

OBJECTIVE

This systematic review aims to synthesise existing literature to examine the relationship between natural food chemical components and reported symptoms.

DESIGN

A systematic literature review was completed. Databases CINAHL (Ebscohost), Medline (Ovid), Scopus, Informit Health and Google Scholar were searched to identify relevant articles. The population included human studies of adults (≥17 years) and excluded those with IgE-mediate food allergies. Studies examining food chemical components or 'food chemical elimination diets' and symptoms were included. Data was synthesised based on clinical conditions and specific food chemical components examined. The risk of bias was assessed using the Academy of Nutrition and Dietetics 'Quality Criteria Checklist: Primary Research'.

RESULTS

Of the 1659 articles retrieved, 21 met inclusion criteria. This included eight randomised controlled trials, four non-randomised controlled trials, four cohort studies with placebo-controlled challenge, one prospective cohort study, three cross sectional cohort studies, one case-controlled study. Available studies support the role of a low-histamine diet for symptoms in chronic urticaria and low-salicylate diet for reducing sino-nasal symptoms in aspirin exacerbated respiratory disease and chronic rhinosinusitis and/or asthma. While further evidence is needed to verify the role of glutamate in respiratory, pain, asthma and gastrointestinal symptoms.

CONCLUSIONS

Food chemical elimination diets may improve condition-specific symptoms across the adult cohorts outlined within this review, with the strongest evidence to support the role of a low-histamine diet for management of symptoms in chronic urticaria and a low-salicylate diet in aspirin exacerbated respiratory disease and/or asthma. Further well-designed trials are needed to elucidate the effect of specific natural food chemical components on symptoms.

TRIAL REGISTRATION

Systematic review number: CRD42022322511.

Measurement of diamine oxidase (DAO) during low-histamine or ordinary diet in patients with histamine intolerance

BACKGROUND/OBJECTIVES

Quantification of diamine oxidase (DAO) concentrations in serum has been proposed as an adjunctive diagnostic modality for the evaluation of histamine intolerance (HIT). Limited empirical data exist concerning the influence of dietary patterns on DAO levels.

SUBJECTS/METHODS

In the context of a prospective study employing a crossover design, 18 individuals diagnosed with HIT were randomized to initiate either a low histamine diet (LHD) or a conventional mixed diet (MXD). Serum DAO concentrations were measured at the commencement of the study and following each dietary phase. A control group underwent analogous DAO assessments without imposition of dietary constraints.

RESULTS

During the time when a diet restricted in histamine was implemented, noticeable differences in changes in DAO levels did not become apparent when compared to the changes observed during the mixed (MXD) phase. Specifically, among the group, 10 of the 18 patients exhibited elevated DAO values subsequent to the LHD regimen, while the remaining eight displayed either reduced or unchanging DAO levels. The prevalence of elevated DAO levels in the LHD group did not differ significantly from that observed in the control group during the MXD phase. Additionally, during the LHD phase, patients reported a significant reduction in gastrointestinal and cutaneous symptoms.

CONCLUSIONS

This prospective investigation underscores the enduring utility of a histamine-restricted diet, coupled with structured dietary reintroduction, as an efficacious diagnostic approach for individuals presenting with suspected food-related histamine hypersensitivity. Notably, the measurement of DAO levels appears to furnish only a limited capacity to discern dietary-induced fluctuations. Notwithstanding, the dynamics of DAO alteration do not appear to exhibit a discernible association with specific dietary patterns, a finding consistent across both patient and control groups.

Urticaria

The relevance of the disease is due to its prevalence ― for acute urticaria up to 20% with predominance in the paediatric population, for chronic spontaneous urticaria up to 0.5–5% of the population. The course of the disease is characterised by unpredictability of prognosis of duration, effectiveness of standard therapy, serious impact on the quality of life of the patient, his relatives, the burden on health authorities. The lack of accurate understanding of the mechanisms of disease development, a wide range of pathogenetic treatment complicates the possibility of rapid achievement of drug remission. The clinical Recommendations contain up-to-date information on epidemiology, pathogenesis, clinical picture, differential diagnosis, possibilities of examination and stage treatment, including immunobiological therapy. The procedure of medical care, prophylaxis and dispensary observation, criteria for assessing the quality of patient management and supporting material, including questionnaires to assess the severity of the condition and the effectiveness of treatment are outlined. Clinical recommendations on urticaria are intended for practicing physicians of all specialities, students, teachers of medical schools, residents, postgraduates and researchers.

Myths and Facts about Food Intolerance: A Narrative Review

Most adverse reactions to food are patient self-reported and not based on validated tests but nevertheless lead to dietary restrictions, with patients believing that these restrictions will improve their symptoms and quality of life. We aimed to clarify the myths and reality of common food intolerances, giving clinicians a guide on diagnosing and treating these cases. We performed a narrative review of the latest evidence on the widespread food intolerances reported by our patients, giving indications on the clinical presentations, possible tests, and dietary suggestions, and underlining the myths and reality. While lactose intolerance and hereditary fructose intolerance are based on well-defined mechanisms and have validated diagnostic tests, non-coeliac gluten sensitivity and fermentable oligosaccharide, disaccharide, monosaccharide, and polyol (FODMAP) intolerance are mainly based on patients' reports. Others, like non-hereditary fructose, sorbitol, and histamine intolerance, still need more evidence and often cause unnecessary dietary restrictions. Finally, the main outcome of the present review is that the medical community should work to reduce the spread of unvalidated tests, the leading cause of the problematic management of our patients.

Modern Approaches to the Management of Patients with Urticaria

The Union of Pediatricians of Russia together with the Russian Association of Allergologists and Clinical Immunologists and the Russian Society of Dermatovenerologists and Cosmetologists have developed new clinical guidelines for the urticaria in adults and children. Urticaria is a common disease; its various clinical variants are diagnosed in 15–25% of people in the global population, and a quarter of all cases belongs to chronic urticaria. The prevalence of acute urticaria is 20%, and 2.1–6.7% in child population, whereas acute urticaria is more common in children than in adults. The prevalence of chronic urticaria in adults in the general population is 0.7 and 1.4%, and 1.1% in children under 15 years of age, according to the systematic review and meta-analysis, respectively. This article covers features of epidemiology, etiology, and pathogenesis of the disease with particular focus on differential diagnostic search. Guidelines on treatment and step-by-step therapy scheme (both based on principles of evidencebased medicine) for pediatric patients were presented. Clarification on the analysis of the therapy efficacy and the degree of disease activity was given.

Dietary strategies for chronic spontaneous urticaria: an evidence-based review

Although the relationship between diet and chronic spontaneous urticaria (CSU) remains elusive, several patients seek dietary modifications as they are easy and cost-effective. Adequate patient education and counseling are crucial as modified diets may be beneficial for a subset of antihistamine refractory CSU patients, and no modality currently exists to identify these patients. Elimination of food items based exclusively on patient history may lead to unnecessary restrictions in most cases resulting in nutritional deficiencies and impaired quality of life. Several dietary strategies have been tried till date with varying rates of success and evidence. This review highlights the various dietary strategies along with their levels of evidence, which may help the treating dermatologists and physicians to counsel CSU patients and make evidence-based treatment decisions. There is grade A recommendation for the elimination of food additives (artificial pseudoallergens), personalized diets, vitamin D supplementation, Diamine oxidase supplementation and probiotics (in children), grade B recommendation for dietary elimination of red meat, fish and their products, natural pseudoallergens (fruits, vegetables, and spices), and low-histamine diet, while dietary elimination of gluten (with concomitant celiac disease) has grade C recommendation. Notably, elimination diets should be continued for at least 3 consecutive weeks to assess their effectiveness.

Choroidal thickness and retinal nerve fiber layer analysis in chronic spontaneous urticaria

Aim: In this study, we investigated the effects of chronic spontaneous urticaria on the choroid and retinal nerve fiber layer. Material and Method: The patient group consisted of newly diagnosed 54 chronic spontaneous urticaria (CSU ) patient and the control group consisted of 54 healthy volunteer. Choroidal and retinal nerve fiber layer (RNFL) thickness measurements were performed with Cirrus HD-OCT (Carl Zeiss Meditec Inc., Dublin, CA, USA) 30 minutes after pupil dilation with 0,5% tropicamide. Results: In the patient group, nasal choroidal thickness (NCT) was 290.11±43.16 μm, subfoveal choroidal thickness (SFCT) was 339.17±37.709 μm, temporal choroidal thickness (TCT) was 296.00±42.859 μm, mean choroidal thickness (MCT) was 308.33±35.923 μm and RNFL thickness was 91.11±7.393 μm. NCT was 248.42±35,742 μm, SFCT 276.56±40.04 μm, TCT 253.69±37.384 μm, MCT 259.50±32,986 μm and RNFL thickness 92.19±8.719 μm in the control group. When we examine the p value, it is seen that both groups are similar to each other in terms of RNFL thickness (p=0.326), while there is a significant thickening in all choroidal regions of patients with CSU, including NCT, SFCT, TCT, MCT (p=0.000, p=0.000, p=0.000, p=0.000, respectively). Conclusion: The choroid is affected in CSU and choroidal thickness can be a noninvasive method that can be used in diagnosis CSU. However, studies of longer disease durations may provide more illuminating information about CSU and choroid and RNFL.

Basal Serum Diamine Oxidase Levels as a Biomarker of Histamine Intolerance: A Retrospective Cohort Study

Background: Histamine Intolerance (HIT) is a multifaceted pseudoallergic disorder possibly due to defective histamine metabolism. Diamine oxidase (DAO) contributes to histamine degradation and can be measured in the serum. The role of DAO measurement in the diagnostic work-up of HIT still remains unclear, and conflicting results have been reported in the literature. Therefore, we aimed to evaluate the possible clinical usefulness and consistency of DAO value ranges as provided by the assay manufacturer and verify whether they could predict the response to treatment. Methods: We retrospectively analyzed 192 outpatients with HIT symptoms and measured serum DAO values at baseline. Patients were prescribed either with low-histamine diet and/or enzymatic supplementation according to symptom severity and re-evaluated six to eight months later. Patients were stratified into three groups according to DAO levels: <3 U/mL, 3−10 U/mL, and >10 U/mL. HIT severity was assessed on a scale of 1 to 5 before and after treatment. Results: A total of 146 patients completed the study. Gastrointestinal and cutaneous symptoms, often associated with headache, were more frequent in subjects with DAO < 10 U/mL. Symptom severity and DAO ranges were correlated. Patients with intermediate DAO levels (3−10 U/mL) showed a more complex clinical phenotype but also a more significant improvement in symptom severity (score reduction 50%, interquartile range (IQR) = 33−60%) when compared to patients with low DAO (40%, IQR = 20−60%; p = 0.045) or high DAO (33%, IQR = 0−50%; p < 0.001). Complex clinical phenotypes were also more frequent in patients with intermediate DAO levels. Conclusions: HIT is characterized by typical symptoms and low levels of DAO activity. Symptom severity was associated with the degree of DAO deficiency. Patients with DAO values between 3 and 10 U/mL show the best response to treatment (low-histamine diet and/or DAO supplementation). DAO value could arguably be considered as a predictor of clinical response to treatment. Prospective studies are needed to confirm these data.

Histamine Intolerance-A Kind of Pseudoallergic Reaction

Histamine intolerance (HIT) is a common disorder associated with impaired histamine metabolism. Notwithstanding, it is often misdiagnosed as other diseases because of its lack of specific clinical manifestations. HIT did not gain traction until the early 21st century. In this review, we will focus on the latest research and elaborate on the clinical manifestations of HIT, including its manifestations in special populations such as atopic dermatitis (AD) and chronic urticaria (CU), as well as the latest understanding of its etiology and pathogenesis. In addition, we will explore the latest treatment strategies for HIT and the treatment of specific cases.

Nutrition and urticaria

Urticaria is a distressing dermatologic condition for many. Although the wheals of urticaria are characteristically evanescent, lasting less than 24 hours, patients tend to have recurrent episodes. Hives that last less than 6 weeks are considered acute urticaria. Acute urticaria does not routinely require supplementary work-up because the history often identifies a convincing, inciting allergen. Chronic urticaria is defined as episodes that occur for longer than 6 weeks, and there is often not an easily identifiable trigger. For both acute and chronic urticaria, patients frequently report food as a precipitating cause. For acute urticaria, the foods that are associated with true allergies, such as nuts and shellfish, are the most frequent offenders. The relationship between diet and chronic urticaria is not as firmly defined. Many patients unnecessarily restrict their diets, so it becomes the role of dermatologists to help patients identify if there is a reproducible link between their symptoms and their dietary exposures. The literature suggests that diets free from pseudoallergens and histamine-releasing foods may attenuate urticaria. Supplements such as fats, vitamin D, iron, and flavonoids have also been studied and may diminish symptoms.

Guideline on management of suspected adverse reactions to ingested histamine: Guideline of the German Society for Allergology and Clinical Immunology (DGAKI), the Society for Pediatric Allergology and Environmental Medicine (GPA), the Medical Association of German Allergologists (AeDA) as well as the Swiss Society for Allergology and Immunology (SGAI) and the Austrian Society for Allergology and Immunology (ÖGAI)

Adverse reactions to food or food ingredients are more often perceived than objectively verifiable. However, reliable laboratory tests are often lacking. As a result, people with perceived adverse reactions to food often follow extensive elimination diets for years and unnecessarily restrict their diet, as in the case of the frequently suspected histamine intolerance. In this condition, laboratory parameters such as the determination of diamine oxidase in serum have been shown to be inconclusive. The lack of symptom reproducibility calls into question the clinical picture of adverse reactions to ingested histamine. In order to approach persons with perceived histamine intolerance and to support them in moving from blanket restrictions, which are often unnecessarily strict, to effective personalized therapeutic strategies, the present guideline of the Working Group on Food Allergy of the German Society of Allergology and Clinical Immunology (DGAKI) in cooperation with the Medical Association of German Allergists (AeDA), the Pediatric Allergology and Environmental Medicine (GPA) as well as the Swiss Society of Allergology and Immunology (SGAI) and the Austrian Society of Allergology and Immunology (ÖGAI) recommends a practicable diagnostic and therapeutic approach.

Role of nutritional supplements in selected dermatological disorders: A review

BACKGROUND

While a plethora of literature continues to be published on the role of nutritional agents both in lay press and indexed journals, the data is not on a firm footing and leaves the dermatologist in a quandry and the patient confused. The various agents include vitamins, minerals, amino acids, antioxidants, diets & gluten. A proper knowledge of the role of nutritional supplements in dermatological diseases can be a useful tool in advising the patients and in certain cases ameliorating the disorder.

PATIENTS/METHODS

Literature review of last 15 years was made using the terms "diet in dermatology," "nutrition and skin," "nutritional supplements in dermatology," "nutritional agents and acne," "nutritional agents and alopecia," and "nutritional agents and psoriasis."

RESULTS

While there are multiple publications on the use of nutritional supplements for amelioration of skin diseases, most of them are based on either associations or in vitro studies, but very few transcend the rigors of a clinical trial or the holey grail of a double-blinded randomized controlled trial. There seem to be some evidence in acne, psoriasis, telogen effluvium, urticaria & vitiligo. Coeliac disease and dermatitis herpetiformis have a strong link with diet. Rosacea has a strong link with certain foods, but the other disorders like melasma, aphthous stomatitis do not have any scientifically validated association with diet.

CONCLUSIONS

Our updated review examines the role of nutritional supplements and antioxidants in various dermatological disorders. We have found that there are varying levels of evidence with notable associations of low glycemic diet & acne, fish oil & weight loss with psoriasis, fish oils & probiotics with atopic dermatitis & vitamins & botanical extracts with vitiligo. The evidence for diet and nutrition in bullous disorders and photoageing is scarce. The role of low histamine diet in urticaria is useful in select cases of episodic urticaria. Rosacea is triggered by hot and spicy food . Apart from gluten and Dermatitis Herpetiformis, no diet can be considered disease modifying in our reveiw. The lack of comparison of nutritional or dietary modiffication with conventional validated agents, makes the data difficult to translate in real world patient management.

Effect of the Mediterranean diet in patients with chronic spontaneous urticaria

OBJECTIVE

Patients with chronic spontaneous urticaria often want to be informed about dietary modifications. There have been many studies evaluating dietary approaches in chronic spontaneous urticaria. In this study, we aimed to investigate the relationship between adherence to the Mediterranean diet and chronic spontaneous urticaria.

METHODS

In this cross-sectional case-control observational study, 100 patients (70 males and 30 females, mean age: 38.6±13.0 years) with chronic spontaneous urticaria and age- and sex-matched 100 healthy controls 70 males and 30 females, mean age: 38.7±13.8 years) were enrolled. A validated 14-item questionnaire evaluating the Mediterranean diet score was used for the assessment of adherence to the Mediterranean diet. The severity and the control of chronic spontaneous urticaria were assessed by Urticaria Activity Score over 7 days and Urticaria Control Test, respectively.

RESULTS

The mean Mediterranean diet score in the patient group was 5.40±1.88, whereas in healthy controls it was 6.30±1.39 (p<0.001). The Urticaria Activity Score over 7 days score of the patients was negatively correlated with the Mediterranean diet score, whereas the Urticaria Control Test score was positively correlated.

CONCLUSION

We reported that adherence to the Mediterranean diet may be an independent factor that decreases the risk of chronic spontaneous urticaria. It may also reduce the severity of chronic spontaneous urticaria symptoms.

Triggers of Exacerbation in Chronic Urticaria and Recurrent Angioedema-Prevalence and Relevance

Patients with urticaria and angioedema often have triggers that cause an outbreak or a swelling episode or worsen their chronic condition. Exploring these factors with each patient may result in better understanding and control of their disease. Patients should be advised to avoid known triggers, if feasible, or prepare to prevent or control an exacerbation with appropriate pretreatment if avoidance is not possible. In this review, we describe and discuss a variety of factors for which there is evidence that they cause or exacerbate chronic spontaneous urticaria and angioedema. These potentially exacerbating factors include drugs, food additives, and naturally occurring pseudoallergens, mental stress, and trauma.

Relationship between allergic rhinitis and diamine oxidase activity: A preliminary report

AIM

To analyze the diamine oxidase (DAO), the main catabolic enzyme of histamine, degradation activity and its relation with symptoms of persistent allergic rhinitis.

METHODS

In this descriptive and analytical observational study, we collected DAO activity levels and the nasal peak inspiratory flow.

RESULTS

Enzymatic activity deficit in 108 patients was 46.3% (95% CI, 0.44 - 0.63), 33.33% in mild and 47.92% in moderate/severe rhinitis (p = 0.376). The nasal peak inspiratory flow in patients with a deficit in DAO activity was 76.30 ± 28.40 L/min compared to 93.62 ± 37.50 L/min in patients with normal enzymatic activity (p = 0.010).

CONCLUSIONS

It seems that the lower the catabolic activity of DAO, the lower the nasal peak inspiratory flow observed. Although DAO activity levels could be a severity biomarker in allergic rhinitis, a cause-effect association cannot be concluded. The enzyme could be another actor in the pathophysiology of allergic rhinitis.

Low-Histamine Diets: Is the Exclusion of Foods Justified by Their Histamine Content?

A low-histamine diet is currently the most advised strategy to prevent the symptomatology of histamine intolerance. Conceptually, these diets should be founded on the exclusion of histamine-containing foods, although a certain disparity is found within the list of excluded foods in accordance with the different low-histamine diets available in the literature. This study aimed to critically review low-histamine diets reported in the scientific literature, according to the histamine and other biogenic amine contents of the excluded foods. A total of ten scientific studies that provided specific recommendations on the foods that must be avoided within the framework of a low-histamine diet were found. Overall, the comparative review brought out the great heterogenicity in the type of foods that are advised against for histamine intolerant individuals. Excluded foods were, in most cases, different depending on the considered diet. Only fermented foods were unanimously excluded. The exclusion of 32% of foods could be explained by the occurrence of high contents of histamine. The presence of putrescine, which may interfere with histamine degradation by the DAO enzyme at the intestinal level, could partly explain the reason why certain foods (i.e., citrus fruits and bananas) were also frequently reported in low-histamine diets. Finally, there was a range of excluded foods with an absence or very low levels of biogenic amines. In this case, certain foods have been tagged as histamine-liberators, although the mechanism responsible has not yet been elucidated.

Chronic spontaneous urticaria in clinical practice: a pilot survey about attitudes and perceptions on assessment, diagnostic work-up and dietary management

BACKGROUND

Chronic spontaneous urticaria (CSU) is a heterogeneous condition whose management can be complex and challenging. The aim of this study is to evaluate physicians' attitudes regarding practical aspects of CSU management, including adherence to international guidelines, criteria and instruments for CSU assessment, prescription of laboratory investigations and role of dietary measures.

METHODS

A cross-sectional survey was conducted using a study-specific questionnaire. It was administered to a group of physicians with a specialist interest in CSU from different areas of Italy definable as "CSU experts" (group A; N.=21) and subsequently to other physicians who managed CSU only occasionally in their clinical activity (group B; N.=25).

RESULTS

The EAACI/GA²LEN/EDF/WAO guidelines were considered very or moderately useful by the majority of participants. Significantly more physicians in group A reported that such guidelines were always followed in clinical practice (P=0.0008). Instruments for the assessment of CSU severity/activity and quality of life were used in clinical practice significantly more often by CSU experts as compared to group B. Dietary measures were frequently suggested for CSU patients by nearly three quarters of group B members and by only 5% of CSU experts (P<0.00001). When physicians were asked to indicate the type of laboratory examinations that were commonly performed in patients with longstanding and/or uncontrolled CSU, regardless of history, the investigations most frequently reported were full blood count and thyroid autoantibodies, followed by erythrocyte sedimentation rate and/or C-reactive protein and thyroid function tests.

CONCLUSIONS

The results of the present pilot survey seem to suggest the heterogeneity of the approaches used for CSU management in clinical practice.

Histamine Intolerance: The Current State of the Art

Histamine intolerance, also referred to as enteral histaminosis or sensitivity to dietary histamine, is a disorder associated with an impaired ability to metabolize ingested histamine that was described at the beginning of the 21st century. Although interest in histamine intolerance has considerably grown in recent years, more scientific evidence is still required to help define, diagnose and clinically manage this condition. This article will provide an updated review on histamine intolerance, mainly focusing on its etiology and the existing diagnostic and treatment strategies. In this work, a glance on histamine intoxication will also be provided, as well as the analysis of some uncertainties historically associated to histamine intoxication outbreaks that may be better explained by the existence of interindividual susceptibility to ingested histamine.

Attenuation of Weight Gain and Prevention of Associated Pathologies by Inhibiting SSAO

Obesity is a worldwide prevalent metabolic disorder that is associated with diabetes, among many other diseases. Bearing this in mind, prevention and treatment ways need to be improved. Notably, activity of the enzyme semicarbazide-sensitive amine oxidase (SSAO) is found to be elevated in overweight subjects. Moreover, SSAO inhibition has resulted in an increase of histamine activity in adipose tissue and the limitation of body fat. The current review aims to overview the risks of obesity, rationalize the molecular ways of SSAO activity, and outline the strategies of inhibiting upregulated enzyme levels. It describes the differences between SSAO inhibitors and advances the prospective agents. Based on evidence, caffeine is proposed as an effective, safe, and reliable choice to inhibit SSAO activity. Furthermore, the histamine in adipocytes has been associated with SSAO activity. Therefore, it is suggested as one of the key compounds to be studied for obesity management. To conclude, inhibiting SSAO may attenuate weight gain and prevent related diseases.

Respiratory

Lung disease rivals the position for the top cause of death worldwide. Causes and pathology of the myriad lung diseases are varied, yet nutrition can either affect the outcome or support treatment in the majority of cases. This chapter explores the modifiable risk factors, from lifestyle changes to dietary intake to specific nutrients, anti-nutrients, and toxins helpful for the nutritionist or dietitian working with lung disease patients. General lung health is discussed, and three major disease states are explored in detail, including alpha-1 antitrypsin deficiency, asthma, and idiopathic pulmonary fibrosis. Although all lung diseases have diverse causes, many integrative and functional medical nutrition therapies are available and are not being utilized in practice today. This chapter begins the path toward better nutrition education for the integrative and functional medicine professional.

Association of diet and headache

The global prevalence of migraine as a primary headache has been estimated as 14.4% in both sexes. Migraine headache has been ranked as the highest contributor to disability in under 50 years old population in the world. Extensive research has been conducted in order to clarify the pathological mechanisms of migraine. Although uncertainties remains, it has been indicated that vascular dysfunction, cortical spreading depression (CSD), activation of the trigeminovascular pathway, pro-inflammatory and oxidative state may play a putative role in migraine pain generation. Knowledge about pathophysiological mechanisms of migraine should be integrated into a multimodal treatment approach to increase quality of life in patients. With respect to this, within the integrative health studies growing interest pertains to dietary interventions. Although the number of studies concerning effects of diet on headache/migraine is not yet very large, the current article will review the available evidence in this area. All publications on headache/migraine and dietary interventions up to May 2019 were included in the present review through a PubMed/MEDLINE and ScienceDirect database search. According to the current findings, Ketogenic diet and modified Atkins diet are thought to play a role in neuroprotection, improving mitochondrial function and energy metabolism, compensating serotoninergic dysfunction, decreasing calcitonin gene-related peptide (CGRP) level and suppressing neuro-inflammation. It can also be speculated that prescription of low glycemic diet may be promising in headache/migraine control through attenuating the inflammatory state. Moreover, obesity and headaches including migraine could be attributed to each other through mechanisms like inflammation, and irregular hypothalamic function. Thereby, applying dietary strategies for weight loss may also ameliorate headache/migraine. Another important dietary intervention that might be effective in headache/migraine improvement is related to balance between the intake of essential fatty acids, omega-6 and omega-3 which also affect inflammatory responses, platelet function and regulation of vascular tone. Regarding elimination diets, it appears that targeted these diets in migraine patients with food sensitivities could be effective in headache/migraine prevention. Taken together, dietary approaches that could be considered as effective strategies in headache/migraine prophylaxis include weight loss diets in obese headache patients, ketogenic and low-calorie diets, reducing omega-6 and increasing omega-3 fatty acid intakes.

Is chronic urticaria more than skin deep?

Chronic urticaria is a disease characterized by the appearance of weals, angioedema or both longer than 6 weeks. Degranulation of cutaneous or submucosal mast cells leads to release of mediators including histamine resulting in redness, swelling and itch. Because mast cells are widely distributed throughout the body, the question is why they are not activated systemically or does systemic activation occur without overt end organ dysfunction? We have conducted an exploratory literature search for reports that have evidence of organ-specific dysfunction in chronic urticaria that might justify prospective observational studies. This search revealed some evidence of systemic effects of chronic urticaria in cardiac, respiratory, gastrointestinal, central nervous and musculo-skeletal systems. The relevance of these findings needs to be further determined. However, they justify prospective studies in larger numbers of patients and at different stages of disease activity.

Effects of combination of mizolastine and proteoglycan on chronic urticaria: a randomized controlled trial

The present study aimed to observe the therapeutic effect of combined mizolastine and proteoglycan in chronic urticaria. The patients were randomly divided into the treatment group (n = 56) and the control group (n = 44). The treatment group was medicated with calcium gluconate (10 mg/ time, 1 time/day), vitamin D3 (intramuscular 10 mg/time, 1 time/week), mizolastine (10 mg/time, 1 time/day), and proteoglycan (1.2 g/time, 3 times/day), while the control group was administered with the same drugs except proteoglycan for 4 weeks. After treatment with combined mizolastine and proteoglycan, therapeutic effect with symptoms decline index (SDI) more than 60% was significant different (44 vs. 24, p = 0.000973) and the relapse rate after 2 months was significantly lower (17.9% vs. 38.6%, p = 0.0202). Using ELISA, we found that the IFN-γ (37.88 ± 4.27 pg/mL vs. 21.91 ± 4.95 pg/mL, p = 0.028) levels were specifically increased in the experiment group. The combination of mizolastine plus proteoglycan is effective in treating chronic urticaria with better therapeutic effect and lower relapse rate through promoting IFN-γ production.

Irritable Bowel Syndrome and Dietary Interventions

Irritable bowel syndrome (IBS) is the most prevalent functional gastrointestinal disorder, affecting approximately 14% of the global population. Symptoms of IBS are some of the most common reasons that primary care providers refer patients to gastroenterologists. IBS has a significant economic impact on the health care system and greatly reduces patients' quality of life. The precise cause of IBS remains unknown, but likely involves a variety of factors, such as infection, inflammation, medication, and stress, in a genetically predisposed individual. Physicians can diagnose patients with IBS by obtaining a careful history and physical examination, performing limited testing, and applying the Rome IV criteria. Treating IBS symptoms can be challenging, as no medication cures the disorder. Thus, treatment focuses on improving symptoms and quality of life. Many patients report that symptoms develop from, or are exacerbated by, food. A number of physiologic and biochemical processes can occur with food ingestion that may produce heightened symptoms of IBS. Therefore, dietary interventions to improve IBS symptoms appear to be a reasonable treatment approach. This article discusses the evidence supporting dietary interventions for the treatment of IBS.

Biogenic Amines in Plant-Origin Foods: Are They Frequently Underestimated in Low-Histamine Diets?

Low-histamine diets are currently used to reduce symptoms of histamine intolerance, a disorder in histamine homeostasis that increases plasma levels, mainly due to reduced diamine-oxidase (DAO) activity. These diets exclude foods, many of them of plant origin, which patients associate with the onset of the symptomatology. This study aimed to review the existing data on histamine and other biogenic amine contents in nonfermented plant-origin foods, as well as on their origin and evolution during the storage or culinary process. The only plant-origin products with significant levels of histamine were eggplant, spinach, tomato, and avocado, each showing a great variability in content. Putrescine has been found in practically all plant-origin foods, probably due to its physiological origin. The high contents of putrescine in certain products could also be related to the triggering of the symptomatology by enzymatic competition with histamine. Additionally, high spermidine contents found in some foods should also be taken into account in these diets, because it can also be metabolized by DAO, albeit with a lower affinity. It is recommended to consume plant-origin foods that are boiled or are of maximum freshness to reduce biogenic amine intake.