Usefulness of the Nasal Allergen Provocation Test in the Diagnosis of Shellfish Allergy.

BACKGROUND AND OBJECTIVES: Shellfish allergy is a major cause of food allergy and anaphylaxis worldwide. Several allergenic proteins have been described in the last few years, but the only diagnostic tool that still enables discrimination between allergic and nonallergic sensitized persons is the oral food challenge (OFC). The aim of this study was to evaluate the usefulness of the nasal allergen provocation test (NAPT) as a diagnostic tool in shellfish allergy. METHODS: Forty-five patients with confirmed sensitization to shrimp by a positive skin prick test (SPT) result with a commercial shrimp extract were recruited and classified as sensitized-allergic or sensitized-nonallergic based on current tolerance to shrimp intake, the result of an OFC with a freeze-dried cooked shrimp mixture extract, or a recent history of anaphylaxis induced by shrimp ingestion. These patients and 10 controls not sensitized to shrimp underwent NAPT with a freeze-dried cooked shrimp mixture extract. The response was evaluated using acoustic rhinometry and a visual analog scale. RESULTS: Significant differences (P=.001) were found between the sensitized-allergic group (18/20 positive NAPT, 90%) and both the sensitized-nonallergic group (2/18 positive NAPT, 11.1%) and controls (0/10 positive NAPT). NAPT enables differentiation between allergic and nonallergic persons with a sensitivity of 90%, specificity of 89%, positive predictive value of 90%, and negative predictive value of 89%. CONCLUSIONS: Our results indicate that NAPT makes it possible to differentiate between sensitized symptomatic patients and sensitized tolerant patients and could be a valuable diagnostic tool when assessing shrimp allergy.

Risk Factors in Severe Anaphylaxis: Which Matters the Most, Food or Cofactors?

BACKGROUND AND OBJECTIVE: The prevalence of anaphylactic shock, the most severe manifestation of anaphylaxis, remains unknown. Risk factors and biomarkers have not been fully identified. Objective: To identify risk factors in patients who experience anaphylactic shock. METHODS: Using lipid transfer protein (LTP) allergy as a model, we compared the characteristics of patients who developed anaphylaxis and anaphylactic shock. We recorded demographics, pollen sensitization, foods ingested up to 2 hours before onset of the reaction, and the presence of cofactors. Culprit foods were identified through a compatible clinical history and positive allergology work-up (skin prick test and/or sIgE). RESULTS: We evaluated 150 reactions in 55 patients with anaphylaxis (134 reactions) and 12 with anaphylactic shock (16 reactions). Patients in the anaphylaxis group experienced twice as many reactions (mean [SD], 2.4 [2.5] for anaphylaxis vs 1.3 [1.5] for anaphylactic shock; P<.02). No relationship was found between any food group and severity of the reaction. The most frequent food involved in both groups of patients was the combination of several plant-derived foods (plant food mix), followed by peach and nuts. Indeed, in the reactions caused by plant food mix, the presence of a cofactor was observed more often than in other food groups. On the other hand, cofactors were not present in peach- and nut-related reactions. Exercise was the most frequent cofactor in all groups. CONCLUSION: In our series, the severity of the reactions was not determined by the kind of food or presence of a cofactor. Anaphylactic shock seems to be an infrequent presentation that may be associated with other individual-related factors requiring further evaluation.

Spanish Society of Allergology and Clinical Immunology (SEAIC) Vision of Drug Provocation Tests.

The controlled drug provocation test (DPT) is currently considered the gold standard for the diagnosis of drug allergy. Adverse drug reactions (ADRs) are an increasingly common presenting complaint in both primary and specialized care. In Spain, ADRs are usually assessed via the allergology department, which rules out immunological mechanisms in up to 90% of cases. An adequate approach to ADRs clearly impacts the costs and efficacy of the treatments prescribed by other specialists. Consequently, if we did not use DPTs, patients would require more expensive, more toxic, and less effective treatments in many cases. In recent years, many new drugs have been developed. This document is intended to be a practical guideline for the management of DPTs according to the vision of the Spanish Allergology Society. The diagnostic work-up begins with a detailed clinical history. Skin tests are only useful for some medications, and in most cases the diagnosis can only be confirmed by DPT. Although cross-reactivity is common, DPTs can confirm the diagnosis and help to find an alternative drug. Programmed individualized patient management based on the type of drug to be studied and the patient´s comorbidities usually enables a solution to be found in most cases.

Shellfish Allergy: Unmet Needs in Diagnosis and Treatment.

Seafood is a major cause of food allergy and anaphylaxis worldwide. Shellfish is included among the "big eight" food groups, which are responsible for more than 90% of all cases of food allergy. Approximately 2.5% of the world's population has experienced an adverse reaction to seafood. Seafood allergy is one of the most frequent and lethal allergies that exist. The several allergenic proteins involved in allergic reactions that have been described in recent years include tropomyosin, arginine kinase, myosin light chain, and sarcoplasmic calcium-binding protein. Despite all the data reported in the last few years, shellfish allergy is still diagnosed and treated as it was 50 years ago. The only effective treatment to prevent allergic reactions to shellfish is avoidance. This review aims to update recently published data on shellfish allergy and to highlight those areas that have yet to be resolved.

Cryptosporidium meleagridis in an Indian ring-necked parrot (Psittacula krameri).

OBJECTIVE: To perform a morphological and genetic characterisation of a Cryptosporidium infection in an Indian ring-necked parrot (Psittacula krameri) and to compare this with C meleagridis from a turkey. DESIGN: Tissue and intestinal sections from an Indian ring-necked parrot were examined microscopically for Cryptosporidium. The organism was also purified from the crop and intestine, the DNA extracted and a portion of the 18S rDNA gene amplified, sequenced and compared with sequence and biological information obtained for C meleagridis from a turkey as well as sequence information for other species of Cryptosporidium. RESULTS: Morphological examination of tissue sections from an Indian ring-necked parrot revealed large numbers of Cryptosporidium oocysts attached to the apical border of enterocytes lining the intestinal tract. Purified Cryptosporidium oocysts measured about 5.1 x 4.5 microns, which conformed morphologically to C meleagridis. The sequence obtained from this isolate was identical to sequence information obtained from a C meleagridis isolate from a turkey. CONCLUSION: Cryptosporidium meleagridis was detected in an Indian ring-necked parrot using morphological and molecular methods. This is the first time that this species of Cryptosporidium has been reported in a non-galliform host and extends the known host range of C meleagridis.

Neuroangiostrongyliasis and other parasites in tawny frogmouths (Podargus strigoides) in south-eastern Queensland.

The neurological, clinical and pathological findings and endoparasites in 10 wild tawny frogmouths (Podargus strigoides) presented to the Australian Wildlife Hospital in Beerwah, Queensland during a 28-day period in May 2009 are reported. Affected birds had a history of being found in poor body condition on the ground and unable to fly. Clinical examination revealed paresis with variable but generally weakened deep pain responses, withdrawal reflexes and an inability to perch. Severely affected birds that failed to respond to anti-inflammatory, antibiotic and anthelmintic treatments all had larval Angiostrongylus cantonensis in the brain and or spinal cord, with occasional larvae found in the visceral organs. Other parasites detected included the liver fluke, Brachylecithum podargi, the intestinal nematode, Allodapa suctoria, an unidentified species of Trichostrongylus and unidentified cestodes. Gametocytes of Leucocytozoon sp. were found in peripheral blood smears and low numbers of microfilariae were found in histological sections of various blood vessels of several birds. However, no adult filarioids were recovered. Unidentified subcutaneous mites were identified in the connective tissue of the thoracic inlet. Attempts to treat two birds with ivermectin or oxfendazole-praziquantel were unsuccessful, but a third bird treated with a combination of steroidal and non-steroidal anti-inflammatory therapy followed by moxidectin steadily recovered, such that by 6 weeks post presentation its ability to perch, grasp, fly and judge distances was considered normal and it was subsequently released.