Acute gastric anisakiasis: 28 cases during the last 10 years

RE.GA.IN.: the Real-world Gastritis Initiative-updating the updates

At the end of the last century, a far-sighted 'working party' held in Sydney, Australia addressed the clinicopathological issues related to gastric inflammatory diseases. A few years later, an international conference held in Houston, Texas, USA critically updated the seminal Sydney classification. In line with these initiatives, Kyoto Global Consensus Report, flanked by the Maastricht-Florence conferences, added new clinical evidence to the gastritis clinicopathological puzzle.The most relevant topics related to the gastric inflammatory diseases have been addressed by the Real-world Gastritis Initiative (RE.GA.IN.), from disease definitions to the clinical diagnosis and prognosis. This paper reports the conclusions of the RE.GA.IN. consensus process, which culminated in Venice in November 2022 after more than 8 months of intense global scientific deliberations. A forum of gastritis scholars from five continents participated in the multidisciplinary RE.GA.IN. consensus. After lively debates on the most controversial aspects of the gastritis spectrum, the RE.GA.IN. Faculty amalgamated complementary knowledge to distil patient-centred, evidence-based statements to assist health professionals in their real-world clinical practice. The sections of this report focus on: the epidemiology of gastritis; Helicobacter pylori as dominant aetiology of environmental gastritis and as the most important determinant of the gastric oncogenetic field; the evolving knowledge on gastric autoimmunity; the clinicopathological relevance of gastric microbiota; the new diagnostic horizons of endoscopy; and the clinical priority of histologically reporting gastritis in terms of staging. The ultimate goal of RE.GA.IN. was and remains the promotion of further improvement in the clinical management of patients with gastritis.

Intestinal Giardiasis in Children Undergoing Upper Endoscopy for Unexplained Gastrointestinal Symptoms: Implication for Diagnosis

BACKGROUND

Giardia lamblia is a flagellated protozoan causing diarrheal outbreaks worldwide. Microscopic stool examination is widely used. We conducted this study to explore intestinal giardiasis in children undergoing upper endoscopy for unexplained gastrointestinal symptoms.

METHODS

The study included 160 children undergoing upper endoscopy for unexplained gastrointestinal symptoms (patients) and 90 children as controls. We collected stool samples for microscopic examination and ELISA coproantigen detection from all participants. We examined duodenal biopsies for patients.

RESULTS

In patients, stool examination revealed Giardia in 23.8% and coproantigen detection was positive in 37.5%. Endoscopic duodenal biopsies revealed Giardia trophozoites in 5% of patients, in addition to various pathological changes.

CONCLUSION

Giardiasis was significantly higher (P = 0.001) in children with unexplained gastrointestinal complaints than the controls. Diagnosis by coproantigen detection was superior to microscopic stool examination, with a sensitivity of 90.9%. Duodenal biopsies examination confirmed the infection in fewer cases but added other diagnostic information.

Mimics of Crohn's Disease

Crohn's disease is a chronic inflammatory disease that can affect any portion of the gastrointestinal tract. Associated symptoms can vary based on the severity of disease, extent of involvement, presence of extraintestinal manifestations, and development of complications. Diagnosis is based on a constellation of findings. Many diseases can mimic Crohn's disease and lead to diagnostic conundrums. These include entities associated with the gastrointestinal luminal tract, vascular disease, autoimmune processes, various infections, malignancies and complications, drug- or treatment-induced conditions, and genetic diseases. Careful consideration of possible causes is necessary to establish the correct diagnosis.

A case of anisakiasis invading the stomach and the colon at the same time after eating anchovies

Anisakiasis of the gastrointestinal tract is caused by the ingestion of raw fish or uncooked food infested with Anisakis larvae. A large number of cases of gastric anisakiasis have been reported in countries where the eating of raw fish is customary. However, there have been few reports of anisakiasis of the colon confirmed by colonoscopy and also very few reports of endoscopic ultrasonographic findings of anisakiasis. A 47-year-old man had epigastric pain with nausea after eating raw anchovies. Endoscopy found a living tubular structure penetrating into the lesser curvature of the stomach and the midtranseverse colon area. It was withdrawn with biopsy forceps. We report a case of anisakiasis simultaneously invading the stomach and the colon confirmed by endosopic utrasonographic findings and biopsy findings.

Anisakidosis of the sigmoid colon disguising as metastatic carcinoma: a case report and review of the literature

Intestinal anisakidosis is a rare nematode infestation caused by the ingestion of larvae-infected raw or undercooked fish. Most cases are incidentally diagnosed during surgery for other reasons. We present such a case of anisakid larvae seen in a patient's sigmoid colon resected for adenocarcinoma, where a subserosal nodule caused by the inflammatory reaction to the worm was presumed to be a lymph node involved by metastatic tumor. With the increasing popularity of raw fish consumption, the incidence of this parasitic infection is bound to increase, requiring surgical pathologists to be cognizant of its existence and aware of its histologic appearance.

Histopathologic diagnosis of eosinophilic conditions in the gastrointestinal tract

Eosinophils, a constitutive component of the columnar-lined gastrointestinal tract, play an essential role in allergic responses and parasitic infections. The tissue density of these cells also increases in a variety of conditions of uncertain etiology. With the exception of the esophageal squamous epithelium, in which no eosinophils are normally present, the population of normal eosinophils in the remainder of the luminal gut is poorly defined. Therefore, histopathologists must rely on their subjective judgment to determine when a diagnosis of eosinophilic gastritis, enteritis, or colitis should be rendered. Eosinophilic esophagitis is currently the best defined and most studied eosinophilic condition of the digestive tract; therefore, the confidence in accurate diagnosis is increasing. In contrast, the characteristic clinicopathologic features of eosinophilic conditions affecting other parts of the digestive tract remain somewhat elusive. This review was designed to present pathologists with simple and practical information for the biopsy-based histopathologic diagnosis of eosinophilic esophagitis, gastritis, enteritis, and colitis. It was prepared by critically reviewing more than 200 articles on the topic, along with incorporating evidence accumulated through our own collective experience. We anticipate that by increasing pathologists' confidence in reporting these abnormal but often nameless eosinophilic infiltrates, we can help better define and characterize their significance.

Eosinophilic gastritis: histopathological characterization and quantification of the normal gastric eosinophil content

There is limited information about normal eosinophil counts in the gastric mucosa. The purpose of this study was to evaluate the histopathology of 60 patients whose biopsies showed increased eosinophils in the gastric mucosa. We also investigated the eosinophil content in gastric biopsies from normal controls (matched for age, sex, and zip code), from patients with Helicobacter pylori gastritis, and patients with Crohn's disease. Eosinophils were counted in five random high-power fields (HPFs) and reported in eosinophils/mm(2). Involvement of the muscularis mucosae or submucosa, sheets of eosinophils, and infiltration of the gastric epithelium were also evaluated. The median eosinophil count in the study patients was 539 eosinophils/mm(2); mean±SD=653±418 eosinophils/mm(2); range 127-2108. Sheets of eosinophils were seen in 38 patients, 27 showed involvement of the muscularis mucosae or submucosa. There were 7 patients without epithelial infiltration by eosinophils, whereas 34 were tallied as rare and 19 were scored as abundant. No study patient had no evidence of H. pylori. The mean eosinophil count for the 135 normal controls was 15.5±16.8 SD eosinophils/mm(2) (range 0-110); in the 93 controls with H. pylori gastritis the mean eosinophil count was 25±32.6 SD eosinophils/mm(2) (range 0-219); and for the 53 controls with Crohn's disease it was 31.4±44.4 SD eosinophils/mm(2) (range 0-203). There were no significant differences between the counts in biopsies from the antrum and corpus, and no significant variations by age, geographic location, or season. This study confirms that, in the United States population, the normal gastric eosinophilic counts are usually <38 eosinophils/mm(2). We recommend 'histological eosinophilic gastritis' for the diagnosis of gastric biopsies that show an average density ≥127 eosinophils/mm(2) (or ≥30 eosinophils per HPF) in at least five HPFs in the absence of known associated causes of eosinophilia.

Anisakiasis, an underestimated infection: effect on intestinal permeability of Anisakis simplex-sensitized patients

Anisakis simplex is a parasite that, if present in uncooked and contaminated saltwater fish, can invade the human gut. Two different clinical situations are recognized: the first, known as a gastrointestinal disease, varying from an asymptomatic episode to vomiting and diarrhea, and the second, classified as an adverse reaction to food, characterized by a wide spectrum of allergic reactions like rhinitis, conjunctivitis, or even anaphylaxis causing hypotension and/or shock. The intestinal epithelium, the major defense system against external molecules, represents an open gate for toxins and allergens if its protective function is compromised. Previous data have demonstrated a strict relationship between an altered intestinal permeability (I.P.) and worsening of the clinical manifestations in patients with adverse reactions to the food. In this article we evaluated the sensitization to A. simplex among patients who referred clinical symptoms of allergy. All subjects underwent commonly used alimentary skin prick test for food allergens, to which Ani s1, an A. simplex allergen, was added. In addition, in A. simplex-sensitized subjects, I.P. was determined upon their enrolment to the study (time 0) and after 6 months of consuming a raw fish-free diet (time 6). Five hundred and forty subjects were screened, and 170 had a positive skin prick test, 87 (51.2%) of whom were positive to Ani s1. Increased I.P. was evidenced in A. simplex-sensitized subjects with worse clinical symptoms, which receded after 6 months' elimination of raw seafood. With our data we demonstrated that the alimentary habit to eat raw fish represents a high risk for the integrity of the intestinal mucosa, and we suggest that this pathological situation may constitute an ideal, under-estimated, open gate for molecules that predispose to other, more important pathologies.

Anisakis simplex: from obscure infectious worm to inducer of immune hypersensitivity

Infection of humans with the nematode worm parasite Anisakis simplex was first described in the 1960s in association with the consumption of raw or undercooked fish. During the 1990s it was realized that even the ingestion of dead worms in food fish can cause severe hypersensitivity reactions, that these may be more prevalent than infection itself, and that this outcome could be associated with food preparations previously considered safe. Not only may allergic symptoms arise from infection by the parasites ("gastroallergic anisakiasis"), but true anaphylactic reactions can also occur following exposure to allergens from dead worms by food-borne, airborne, or skin contact routes. This review discusses A. simplex pathogenesis in humans, covering immune hypersensitivity reactions both in the context of a living infection and in terms of exposure to its allergens by other routes. Over the last 20 years, several studies have concentrated on A. simplex antigen characterization and innate as well as adaptive immune response to this parasite. Molecular characterization of Anisakis allergens and isolation of their encoding cDNAs is now an active field of research that should provide improved diagnostic tools in addition to tools with which to enhance our understanding of pathogenesis and controversial aspects of A. simplex allergy. We also discuss the potential relevance of parasite products such as allergens, proteinases, and proteinase inhibitors and the activation of basophils, eosinophils, and mast cells in the induction of A. simplex-related immune hypersensitivity states induced by exposure to the parasite, dead or alive.

Pathology of non-infective gastritis

The discovery of Helicobacter pylori and its intimate role in the development of the most common form of chronic gastritis has elicited a much-needed interest in non-neoplastic gastric pathology. This has been paralleled by an increase in upper endoscopic examinations, which allow recognition of novel patterns and distribution of mucosal injury. Numerous attempts at classification have been made, most based on the acuteness or chronicity of gastric mucosal injury. In this review, we will not offer a new classification but present a detailed description of the major clinicopathological entities, based either on the salient morphological features or the underlying aetiologies, i.e. iatrogenic, autoimmune, vascular or idiopathic.

Freezing infective-stage larvae from Anisakis simplex and their produce at -20 degrees C for 24 h does not prevent the occurrence of autonomic imbalance in rat ileum

In the present report, we analyze the efficacy of the sanitary regulations to kill the Anisakis simplex larvae (As L3) (heat or freeze) to avoid the gastrointestinal alterations that it provokes. We studied the effects on intestinal contractility (muscular tone, amplitude, and frequency of the twitches and cholinergic and alpha-adrenergic stimulus) of As L3, their crude extracts (CE) and excretory-secretory products (ESP), untreated or heated (60 degrees C for 15 min) or frozen (-20 degrees C for 24 h) using rat ileum and an isometric system. Carbachol and noradrenaline have been used as cholinergic and alpha-adrenergic stimulus, respectively. We determined that viable As L3, their untreated CE and ESP, as well as all their frozen counterparts, altered the intestinal contractile activity and its autonomic control. In contrast, heated As L3, CE, and ESP were incapable of provoking any change in rat ileum motility, suggesting an inhibitory effect by the heating procedure.

IN CONCLUSION

1) The gastrointestinal alterations provoked by As are not necessarily associated with a prior infection; and 2) the storage of the seafood at -20 degrees C during 24 h does not prevent the intestinal autonomic imbalance provoked by As, whereas, the prior heating at 60 degrees C for 15 min may completely prevent such process.

Chronic Anisakiasis of the Ascending Colon Associated with Carcinoma

Chronic anisakiasis of the colon is rare and difficult to diagnose. We report a case of chronic anisakiasis associated with advanced colonic carcinoma. A 69-year-old man was admitted for abdominal pain, diarrhea, and urticaria. Right hemicolectomy was performed because of an obstruction of the ascending colon and a palpable tumor of the right lower abdomen. The lesion was thought to be located in the deeper layers of the ascending colon. Preoperative examinations failed to detect the coexistence of anisakiasis and carcinoma of the colon. The anisakis was identified morphologically in the intestinal wall of the resected specimen and by an elevated titer of an IgE antibody specific to the parasite. Seventy-five cases of colonic and rectal anisakiasis, including the present case, have been reported in Japan. This is the only reported case of anisakiasis to appear in association with colonic carcinoma.

Anisakis infestation: a case of acute abdomen mimicking Crohn's disease and eosinophilic gastroenteritis

Anisakiasis is a rare parasitic disease transmitted to humans by the ingestion of raw fish, which can initially present with acute abdomen. We report the case of a man, a habitual consumer of raw fish, who underwent surgery for acute abdomen, initially attributed to Crohn's disease and then later interpreted as eosinophilic enteritis. Only the subsequent careful histological examination of the surgical specimen, revealing full thickness eosinophilic infiltrate, generally typical of infestation, led to the detection of Anisakis simplex larva. In cases of acute abdomen, in the presence of a positive history of raw fish ingestion, it is therefore reasonable to consider the possibility of anisakiasis.

Anisakis simplex only provokes allergic symptoms when the worm parasitises the gastrointestinal tract

We analysed patients with allergic or digestive symptoms after seafood ingestion in order to assess a correct diet in Anisakis simplex sensitised individuals. A total of 120 patients who suffered allergic and/or digestive symptoms after marine food ingestion were studied. We performed skin prick tests for A. simplex and seafood, total serum and specific serum immunoglobulin E to A. simplex in the acute stage and 1 month later. A gastroscopy was carried out to find larvae in those patients with persistent abdominal pain. A challenge with non-infective larvae was performed to assess a correct diet. Some 96 patients were sensitised to A. simplex. Gastroscopy was performed in 47 and we detected larvae in 24. We compared symptoms, skin tests, total and specific IgE and the latency of appearance of symptoms in patients positive for Anisakis larvae, patients without larvae at gastroscopy and patients without digestive symptoms. There was no difference among the groups. We challenged 22 patients with frozen A. simplex larvae. After allowing deep-frozen seafood in the diet for more than 2 years, no patient suffered a reaction. At this time, we allowed all our patients well-frozen seafood without any allergic reaction occurring. Allergic symptoms are the most frequent manifestation of A. simplex parasitism. We could not find any patient allergic to the thermostable proteins of parasite.

High prevalence of seropositivity to a major allergen of Anisakis simplex, Ani s 1, in dyspeptic patients

Finding evidence of anisakidosis requires invasive methods. We have developed a serological assay based on the detection of an immunoglobulin E (IgE) specifically directed against Ani s 1 protein, a major parasite allergen of Anisakis simplex, which has shown a high level of accuracy in the diagnosis of anisakidosis. We used this tool to determine the prevalence of anti-Ani s 1 IgE in dyspeptic patients and to investigate if its seropositivity could be related to epidemiological factors other than raw fish consumption. A total of 174 dyspeptic patients who submitted to upper digestive tract endoscopy were studied. Specific IgE against Ani s 1 was determined by immunoblotting. Quantitative information on smoking, alcohol consumption, and fish consumption as well as a history of gastric surgery was recorded. Twenty-four (13.8%) patients were seropositive for Ani s 1 protein. The seroprevalence of anti-Ani s 1 IgE increased with age in patients who were less than 62 years old (P = 0.047). Seropositivity to Ani s 1 was associated with the consumption of fish in vinegar (P < 0.001), raw fish (P = 0.001), and smoked fish (P = 0.007). There was no relationship between anti-Ani s 1 IgE seropositivity and the number of cigarettes smoked (P = 0.098) or alcohol intake (P = 0.179). Five patients had undergone previous gastric surgery, and three of those patients were seropositive for Ani s 1 (P = 0.019). In multivariate analysis, the consumption of fish in vinegar (P = 0.006), raw fish (P = 0.017), and smoked fish (P = 0.002) and a history of gastric surgery (P = 0.005) were independent factors associated with anti-Ani s 1 IgE detection. In conclusion, at present, anisakidosis might frequently be underdiagnosed, and it might have a clinical role in patients with upper dyspeptic symptoms. Uncooked-fish ingestion and previous gastric surgery were associated with seropositivity for Ani s 1 protein.

A case of acute gastric anisakiasis provoking severe clinical problems by multiple infection

Acute gastric anisakiasis with multiple anisakid larvae infection is reported. A 68-year-old woman residing in Busan, Korea, had epigastric pain with severe vomiting about 5 hours after eating raw anchovies. Four nematode larvae penetrating the gastric mucosae in the great curvature of the middle body and fundus were found and removed during gastro-endoscopic examination. Another one thread-like moving larva was found in the great curvature of upper body on the following day. On the basis of their morphology, the worms were identified as the 3rd stage larvae of Anisakis simplex. This case is acute gastric anisakiasis provoking severe clinical problems by the multiple infection and the greatest number of anisakid larvae found in a patient in Korea.

[Gastrointestinal anisakiasis. Study of a series of 25 patients]

INTRODUCTION

Infection with the parasite Anisakis simplex is common in Japan and northern European countries. The number of reported cases in Spain has increased since the first description in 1991. The aim of the present study was to evaluate the incidence, clinical patterns, histopathological lesions, treatment, and outcome of Anisakis simplex infection in our environment.

MATERIAL AND METHOD

Cases of gastrointestinal anisakiasis diagnosed in our center from December 1999 to January 2002 were studied. Only patients with detection of the parasite in oral endoscopy or the surgical specimen and those with elevated levels of specific IgE to Anisakis simplex, a clinical picture compatible with anisakiasis, or a history of raw fish intake were included. Epidemiological, clinical and laboratory data, as well as diagnostic, histopathologic and therapeutic features, and outcome in these patients were recorded.

RESULTS

Twenty-five cases of gastrointestinal anisakiasis were diagnosed during the study period, representing an incidence of 3.87 cases per 100 000 inhabitants/year. All the patients had ingested raw anchovies. Two groups were observed. The first group was composed of 10 patients with a gastric form of the infection, in which the main symptom was epigastralgia (90%). Oral endoscopy was performed in all patients and the parasite was detected in five (50%). The second group was composed of 15 patients with intestinal involvement in which the main manifestations were symptoms mimicking appendicitis (80%). The most frequent finding of laparotomy and/or imaging tests (abdominal ultrasonography, intestinal transit, abdominal CAT) was terminal ileitis (80%). Seven patients underwent surgery: intestinal resection was performed in four with detection of Anisakis simplex in three. Eosinophilic infiltration was found in all surgical specimens. Treatment was symptomatic in most of the patients and outcome was favorable in all.

CONCLUSIONS

Infection with Anisakis simplex should be investigated in patients with abdominal pain after intake of raw fish, ileitis of unclear origin, or eosinophilic gastroenteritis.

Gastroallergic anisakiasis: findings in 22 patients

BACKGROUND AND AIMS

Ingestion of Anisakidae larvae in raw seafood may cause anisakiasis. However, despite the high level of consumption of seafood in Spain, only a few cases of anisakiasis have been reported until now. Anisakis simplex can cause allergic reactions in sensitized patients as a result of its parasitism in the gastrointestinal tract. The purpose of this study was to analyse the clinical findings in 22 patients with gastroallergic anisakiasis.

METHODS

Patients with allergic and/or gastric symptoms after seafood ingestion were evaluated in the emergency room of the La Paz General University Hospital. Skin testing for Anisakis simplex and tests on the implicated seafood were performed and amounts of serum-specific immunoglobulin E were assessed. A gastroscopy was performed in those patients with severe allergic or/and persistent gastric symptoms after ingestion of raw or undercooked seafood.

RESULTS

Twenty-two patients were diagnosed with gastroallergic anisakiasis in 1 year. Most patients presented to the emergency room of our hospital with allergic symptoms. Gastric symptoms were usually moderate. Gastroscopy revealed local mucosal oedema and gastric erosion at the point of fixation. Two or more worms were detected in three patients. The mean time of latency of allergic symptoms was 5 h, while the mean time for gastric symptoms was 3 h.

CONCLUSION

Anisakis simplex parasitism was the causative agent of allergic and gastric symptoms. Gastroallergic anisakiasis appears to be a relatively common disease, that may have been underdiagnosed.

Incidence of sensitivity to Anisakis simplex in a risk population of fishermen/fishmongers

BACKGROUND

Anisakis simplex, a fish and cephalopodes parasite, can cause either gastrointestinal symptoms or allergic reactions in humans on eating/handling contaminated fish.

OBJECTIVE

The aim of our study was to determine the capacity of Anisakis simplex to induce specific IgE production and allergic reactions following eating and handling fish in a population at risk.

METHODS

We determined the levels of total IgE, specific IgE, and eosinophil count in 28 fishermen/fishmongers (group A) and 15 healthy donors (group B). A skin prick test (SPT) with extracts from Anisakis and the most common species of fish in our country, were also carried out.

RESULTS

Specific IgE to Anisakis were found in 14 subjects of group A (13 of them had a positive SPT to the same extract) and none of group B (only one subject had a positive SPT). The SPT with fish extracts was positive in 4 patients of group A but in none of group B. Subjects in group A with specific IgE to Anisakis showed higher total IgE levels and eosinophil counts compared with either other individuals of the same group or to those of group B.

CONCLUSIONS

These results indicate that fishermen/fishmongers are a population at risk for Anisakis simplex sensitization and suggest that this kind of sensitization should also be investigated not only in subjects like fishermen/fishmongers who live in countries where fish is likely to be contaminated with Anisakis simplex parasites, but also in those who handle fish for other reasons.

[Study of 13 cases of anisakiasis in the province of Cordoba]

Anisakiasis, or anisakidosis, is a parasitic zoonosis due to the infestation by nematodes of the Anisakidae family, mainly by Anisakis simplex. Notwithstanding its world wide distribution, in our country its appearance is quite recent (1991) with only 19 cases previously reported. We refer 13 cases diagnosed in different hospitals in the province of Córdoba, Spain, from September 1994 to July 1998 which represents the biggest series described in Spain so far. All the patients had a clinical onset as acute abdomen, so that they required early surgery in which a narrowing and inflammatory intestinal segment was observed and subsequently resected. Pathology revealed in such segments an intense eosinophilic infiltrate in the mucosa. Only in one of the cases parasitic fragments were detected in the intestinal mucosa and in the 12 remaining cases the diagnosis was immunological by IgE specific for Anisakis simplex determination and antigens detection of the nematode with monoclonal antibodies. As interesting epidemiologic antecedent we shall mention the fact that all patients referred a usual raw fish consumption (mainly anchovy with vinegar) which is host of third-stage larval of the parasite.

Gastroallergic anisakiasis: borderline between food allergy and parasitic disease-clinical and allergologic evaluation of 20 patients with confirmed acute parasitism by Anisakis simplex

BACKGROUND

Human subjects can be parasitized by Anisakis simplex by eating raw or undercooked fish. Gastric anisakiasis is probably the most frequent clinical entity presenting with severe epigastric pain, vomiting, and diarrhea. In gastroallergic anisakiasis hypersensitivity symptoms predominate.

OBJECTIVE

We sought to describe clinical features, laboratory data, and gastroscopic findings in gastroallergic anisakiasis.

METHODS

We selected 40 patients presenting to the emergency department with an acute allergic reaction, and if we suspected acute parasitism by A simplex, a fiberoptic gastroscopy was performed. In 20 patients we could detect one or more nematodes; these patients are referred to as group A. Those in whom no worm could be found are referred to as group B (n = 20). A detailed history, clinical features, gastroscopic findings, laboratory data, and skin prick test responses were compared.

RESULTS

Long-time intervals of up to 26 hours between fish intake and onset of hypersensitivity symptoms were found (group A, 5.4 +/- 6.3 hours; group B, 5.3 +/- 2.6 hours). Patients in groups A and B did not differ with respect to allergic symptoms (urticaria, angioedema, erythema, bronchospasm, and anaphylaxis) or the mainly light abdominal symptoms (upper abdominal pain, nausea, vomiting, and diarrhea). No significant differences were found with respect to age, time interval between fish intake and onset of symptoms, white cell and eosinophil counts, specific IgE levels against A simplex, or total IgE levels.

CONCLUSIONS

The peculiar sometimes long-time interval between fish intake and onset of allergic symptoms render the diagnosis difficult. An early gastroscopy can confirm the diagnosis and prevent complications. We suggest that gastroallergic anisakiasis be considered a distinct clinical entity in which the predominant symptoms are hypersensitivity symptoms and in which the correct diagnosis is not only important in the management of the acute reaction but also in the prevention of further allergic episodes.

Dietary assessment in five cases of allergic reactions due to gastroallergic anisakiasis

BACKGROUND

Anisakis simplex can cause allergic reactions in sensitized patients. Some of these reactions are related to acute parasitism, as is shown in gastroallergic anisakiasis (anisakiasis with digestive and predominantly allergic symptoms). At present, a nonseafood diet is recommended for all patients with any kind of A. simplex allergy. We wished to confirm the clinical suspicion that patients with allergic symptoms after ingestion of raw or undercooked seafood who are sensitized to A. simplex, and diagnosed with gastroallergic anisakiasis, can tolerate the ingestion of seafood when the parasites are dead and noninfective.

METHODS

We included patients diagnosed with gastroallergic anisakiasis (positive skin prick test or/and serum specific IgE to A. simplex, with one or more parasites found by gastroscopy in the stomach). Patients included in the study gave written, informed consent. Specimens of A. simplex about 2 cm long were selected, placed in capsules, and frozen at -20 degrees C for more than 48 h to make them noninfective. We administered 11 specimens to every patient at the hospital. If they tolerated the larvae, they were told to eat well-frozen seafood (-20 degrees C at least 48 h). After 6 months, the patients were re-evaluated.

RESULTS

Five patients accepted the challenge with noninfective A. simplex larvae. All tolerated the noninfective larvae. After eating deep-frozen seafood for 6 months, no patient suffered a reaction.

CONCLUSIONS

In gastroallergic anisakiasis, the antigens of the live parasite probably cause the allergic symptoms. Patients with this disease can tolerate deep-frozen seafood, in which the parasites are dead.

Gastric anisakiasis: an underestimated cause of acute urticaria and angio-oedema?

Acute urticaria and angio-oedema are common in primary care and in the emergency unit. Food allergy is one possible cause. We describe gastric anisakiasis, in which symptoms are often not obviously related to eating raw fish. A study was made of patients presenting at the emergency department who had allergic symptoms such as urticaria or angio-oedema and had recently eaten raw or undercooked fish. They were divided into two groups. Patients in group A (n = 13) also had abdominal symptoms and were diagnosed as having gastric anisakiasis by fibre-optic gastroscopy where third-stage larvae of Anisakis simplex were visualized and extracted. Skin prick tests and specific IgE to A. simplex were positive. Patients in group B (n = 13) had only allergic symptoms after eating raw fish. Eleven of 13 patients had positive skin prick tests and specific IgE to A. simplex. Three of 15 control subjects had positive skin prick tests and specific IgE to A. simplex. Allergic symptoms appeared from 2 to 20 h (mean 5.0) after ingestion in group A and from 20 min to 23 h (mean 4.3 h) in group B. Gastric symptoms in group A disappeared rapidly after extraction of the larvae. Allergic symptoms disappeared in most cases within the first 24 h. We suggest that the allergic symptoms in group A as well as in group B were mainly due to parasitization by A. simplex in sensitized patients. Gastric anisakiasis may be a widely underdiagnosed clinical entity.