Birch Pollen Related Pear Allergy: A Single-Blind Oral Challenge TRIAL with 2 Pear Cultivars.

Approximately 70% of birch pollen allergic patients in Europe experience hypersensitivity reactions to Immunoglobulin E (IgE) cross-reactive food sources. This so-called pollen-food syndrome (PFS) is defined by allergic symptoms elicited promptly by the ingestion of fruits, nuts, or vegetables in these patients. So far, in the literature, less attention has been given to Bet v 1 cross-reactive symptoms caused by pear (Pyrus communis). In the Netherlands, pears are widely consumed. The primary objective of this study was to measure the type and severity of allergic symptoms during pear challenges in birch pollen allergic patients, with a positive history of pear allergy, using two different pear varieties. Fifteen patients were included, skin prick test (SPT), prick-to-prick test (PTP), specific Immunoglobulin E (sIgE), and single-blind oral challenges were performed with two pear (Pyrus communis) varieties: the 'Cepuna' (brand name Migo®) and the 'Conference' pears. All patients were sensitized to one or both pear varieties. A total of 12 out of 15 participants developed symptoms during the 'Cepuna' food challenge and 14/15 reacted during the 'Conference' challenge. Challenges with the 'Cepuna' pears resulted in less objective symptoms (n = 2) in comparison with challenges with 'Conference' pears (n = 7). Although we did not find significance between both varieties in our study, we found a high likelihood of fewer and less severe symptoms during the 'Cepuna' challenges. Consequently selected pear sensitized patients can try to consume small doses of the 'Cepuna' pear outside the birch pollen season.

Nonsteroidal anti-inflammatory drug hypersensitivity: not always an allergy!

Nonsteroidal anti-inflammatory drugs (NSAIDs) are a major cause of hypersensitivity reactions. Several distinct clinical syndromes are described regarding NSAID hypersensitivity. Such a reaction is generally caused by a non-immunological mechanism. In susceptible patients, COX-1 inhibition leads to an imbalance in lipid mediators such as leukotrienes and prostaglandins. It is essential to distinguish multiple nonspecific NSAID hypersensitivity from single NSAID hypersensitivity, since the management of these respective syndromes is essentially different. This review provides an overview on all the aspects of NSAID hypersensitivity reactions, from pathophysiology to clinical symptoms, leading practical recommendations.

Dutch guideline on food allergy.

The diagnosis of food allergy is established in cases where an immediate allergic reaction has occurred in the last year to a clearly identifiable allergenic food combined with sensitisation to this allergenic food. In all other cases, a food challenge test is required to establish or reject the diagnosis of food allergy. Although the double-blind placebo-controlled food challenge (DBPCFC) test is considered the gold standard, false-positive and false-negative outcomes occur. The incidence of false-positive outcomes is unknown because the results of DBPCFC tests cannot be further confirmed by other tests. If possible, it is important to perform double-blind challenges with recipes that have been validated for blinding and to use challenge procedures that have been proven safe in clinical practice, in order to reduce the risk of unwanted false-positive and false-negative outcomes and severe challenge reactions. The national guideline of the Dutch Society of Allergology describes when challenges are indicated and contraindicated, how food challenges are best conducted and how patients could best be managed and followed-up after the challenge tests have been completed.

Sensitization to lupine flour: is it clinically relevant?

BACKGROUND: Lupinus angustifolius (blue lupine) is used for human and animal consumption. Currently, the lupine content in bread varies from 0% to 10% and from 0.5% to 3% in pastry. Although lupine flour is present in many products, anaphylaxis on lupine flour is rarely seen. OBJECTIVE: The aim of our study was to determine the clinical relevance of sensitization to lupine flour. METHODS: From October 2004 until October 2005, we performed skin prick tests (SPT) with lupine flour, peanut and soy extracts in consecutive patients attending our allergy clinic with a suspected food allergy. In patients sensitized to lupine flour, double-blind placebo-controlled food challenges (DBPCFC) were performed and specific IgE was measured. RESULTS: We tested 372 patients. SPTs with peanut, soy and lupine flour were positive in 135, 58 and 22 patients, respectively. Nine patients with sensitization to lupine flour underwent DBPCFC, which was negative in eight cases. In contrast, one patient experienced significant symptoms. Four of these nine patients suspected lupine by history. Two other patients with a positive history to lupine declined from challenges. In these patients, a 3-day dietary record showed that they could consume lupine without symptoms. Specific IgE in the serum was positive for L. angustifolius, peanut and soy in all nine patients. CONCLUSION: These results demonstrate that clinical lupine allergy is very uncommon, even in the presence of sensitization to lupine flour. The estimated prevalence of lupine allergy, among patients with a suspected food allergy, referred to a tertiary allergy centre in the Netherlands is 0.27-0.81%. In most, although not all cases, sensitization is not clinically relevant and is most likely caused by cross-sensitization to peanut. In selected cases, eliciting doses are low, making significant reactions possible.