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Allergy to peanut oil--clinically relevant?
J Eur Acad Dermatol Venereol. 2007; 21(4):452-5 (ISSN: 0926-9959)
Ring J; Möhrenschlager M
Division Environmental Dermatology and Allergology, GSF/TUM, Department of Dermatology and Allergology Biederstein, Technical University of Munich, Munich, Germany. Johannes.Ring@lrz.tum.de
The increasing prevalence of food allergies (especially allergy to peanuts) has led to a discussion of how safe topical preparations containing peanut oil are with respect to allergy. The major allergens from peanuts are proteins that have been characterized at a molecular level and cloned. Clinical signs of peanut allergy symptoms can be observed on the skin (urticaria), or in the gastrointestinal and/or respiratory tract culminating in cardiovascular symptoms and anaphylactic reactions. In most cases, symptoms are elicited by oral uptake; rarely, a contact urticaria has been described. In vegetable oils, the contents of protein differ depending on the production process: crude oils contain approximately 100 times more proteins than refined oils. This has clear-cut implications for allergic individuals. Quantitative data are available regarding elicitation of symptoms in allergic individuals with a threshold dose of 0.1-1 mg peanut allergen in oral provocation tests. There are anecdotal reports of adverse reactions after topical use of peanut oils. In one epidemiological trial, an association between topical use of skin care products containing peanut oil and the development of peanut allergy was observed; however, the data reflect a retrospective analysis without specifying skin care products containing peanut oil and also without analysing the quantity of topicals used. In contrast, oral tolerance was prevented and allergic sensitization was enhanced in a mouse model using high concentrations of peanut protein. So far, no reliable data are available regarding doses required to induce sensitization against peanut allergen via the epidermal route. A possible induction of sensitization against peanut proteins through contact with the skin via skin care products and the respective protein concentrations is a matter of speculation. Patients with atopic diseases, namely eczema, need appropriate skin care because of the disturbed skin barrier function. The benefit of avoiding damage to skin barrier functions of atopic individuals by the use of peanut protein-containing skin care products seems to outweigh possible risks of sensitization and/or allergy induction against substances contained in those products containing refined peanut oil.
- PreMedline Identifier: 17373969
Beyond allergen avoidance: update on developing therapies for peanut allergy.
Curr Opin Allergy Clin Immunol. 2005; 5(3):287-92 (ISSN: 1528-4050)
Li XM
Pediatric Allergy and Immunology, The Mount Sinai School of Medicine, New York, NY 10029-6574, USA. xiu-min.li@mssm.edu
PURPOSE OF REVIEW: Food allergy has emerged as a significant health problem. Peanut allergy is a major cause of food-induced fatal and near fatal anaphylactic reactions, and the incidence in children is increasing. Attempts to manage peanut allergy by strict avoidance are often unsuccessful. The purpose of this review is to highlight the most promising novel approaches for treating peanut allergy beyond allergen avoidance. RECENT FINDINGS: In the past 5 years much effort has been devoted to developing a treatment for peanut allergy. A recent clinical trial showed that monthly injections of humanized recombinant anti-IgE antibodies increased the threshold for allergic responses of peanut-sensitive individuals, at least to small amounts of peanut protein. However, this treatment cannot cure peanut allergy, and continuous monthly injections are necessary to maintain protection. Developing new therapies for the treatment of peanut allergy is essential. In reviewing publications between 2003 and 2005, several novel therapeutic approaches, tested in the murine model of peanut anaphylaxis appeared promising. Immunotherapy with engineered recombinant peanut protein and bacterial adjuvant significantly protected peanut allergic mice from anaphylaxis. It was also found that a Chinese herbal medicine formula called Food Allergy Herbal Formula-2 completely blocked anaphylaxis up to 5 weeks following therapy. These potent therapeutic effects are associated with immunoregulation of Th1 and Th2 responses. SUMMARY: Although there is no effective and safe therapy for food allergy, many novel approaches are under investigation. Some of these approaches may provide allergists with effective treatments in the near future.
- PreMedline Identifier: 15864090
Late diagnosis of tree nut and sesame allergy in patients previously sensitized but tolerant to peanut.
Ann Allergy Asthma Immunol. 2006; 97(4):443-5 (ISSN: 1081-1206)
Beausoleil JL; Spergel JM
Division of Allergy and Immunology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, USA. beausoleil@email.chop.edu
BACKGROUND: Recent studies have indicated that tolerance to peanut can occur in patients with a history of peanut allergy. Tree nut and sesame allergies have been reported to occur at increased incidence in patients with peanut allergy. Although the coexistence may be simply due to a predisposition to food allergy in these individuals, cross-reactivity has been demonstrated between peanut and tree nuts and between peanut and sesame seed. OBJECTIVE: To describe 3 patients previously sensitized but tolerant to peanut who were subsequently diagnosed as having either tree nut or sesame allergy. METHODS: All the patients had a clinical history of peanut sensitivity and underwent follow-up peanut skin testing to commercial extracts using a bifurcated needle followed by a graded peanut challenge. One patient had a previous positive radioallergosorbent test reaction to sesame and underwent a graded sesame challenge. RESULTS: All the patients had negative peanut challenge results. Two patients subsequently had exposure to tree nuts at home and had systemic reactions and positive skin test reactions to the incriminated tree nut. One patient had a positive challenge reaction to sesame. CONCLUSION: Demonstration of tolerance to peanut may falsely reassure patients and physicians that patients no longer need to avoid tree nuts or sesame. Tree nut and sesame allergies can exist or develop in patients despite the development of tolerance to peanut.
- PreMedline Identifier: 17069095
Accidental ingestions in children with peanut allergy.
J Allergy Clin Immunol. 2006; 118(2):466-72 (ISSN: 0091-6749)
Yu JW; Kagan R; Verreault N; Nicolas N; Joseph L; St Pierre Y; Clarke A
Division of Pediatric Allergy and Clinical Immunology, McGill University Health Centre, 1650 Cedar Avenue L10-413, Montreal, Quebec, Canada.
BACKGROUND: Accidental exposure to peanut has been reported to occur frequently. Total avoidance of peanut is difficult because of its widespread use, manufacturing and labeling errors, utensil contamination, and label misinterpretation. OBJECTIVE: Given the apparent increased awareness of peanut allergy by both consumers and food manufacturers, we aimed to determine the current frequency of accidental exposures occurring in peanut allergic children in Quebec and to identify factors associated with exposure. METHODS: The parents of children with peanut allergy diagnosed at the Montreal Children's Hospital completed questionnaires about accidental exposure to peanut occurring over the period of the preceding year. Logistic regression was used to identify associated factors. RESULTS: Of 252 children, 62% were boys, with a mean age of 8.1 years (SD, 2.9). The mean age at diagnosis was 2.0 years (SD, 2.1). Thirty-five accidental exposures occurred in 29 children over a period of 244 patient-years, yielding an annual incidence rate of 14.3% (95% CI, 10.0% to 19.9%). Fifteen reactions were mild, 16 moderate, and 4 severe. Of 20 reactions that were moderate to severe, only 4 received epinephrine. Eighty percent of children attended schools prohibiting peanut, and only 1 accidental exposure occurred at school. No associated factors were identified. CONCLUSION: Accidental exposure to peanut occurs at a lower frequency than previously reported, but most reactions are managed inappropriately. CLINICAL IMPLICATIONS: Enhanced awareness, access to safer environments, and good food manufacturing practices may have contributed to a lower incidence of inadvertent peanut exposure, but a further reduction and better education on allergy management are desirable.
- PreMedline Identifier: 16890773
Human subjects without peanut allergy demonstrate T cell-dependent, TH2-biased, peanut-specific cytokine and chemokine responses independent of TH1 expression.
J Allergy Clin Immunol. 2006; 118(4):905-14 (ISSN: 0091-6749)
Thottingal TB; Stefura BP; Simons FE; Bannon GA; Burks W; HayGlass KT;
Department of Immunology, University of Manitoba, Winnipeg, Canada.
BACKGROUND: Peanut allergy is a major cause of anaphylaxis. Regulation of immune responses to peanut allergen, particularly why sensitization does not usually progress to allergic reactions, is not well investigated. Most studies focus exclusively on serologic responses and individuals with peanut allergy. OBJECTIVE: We sought to determine the existence, prevalence, and nature of peanut-specific, T cell-dependent cytokine and chemokine responses of adults who eat peanut without having symptoms. METHODS: We developed systems to examine specific immunity in peanut-tolerant individuals who had (1) negative histories and negative peanut skin test responses, (2) negative histories and positive peanut skin test responses, and (3) clinically apparent peanut allergy. After primary culture of PBMCs restimulated with whole peanut extract, we quantified responses characteristic of TH1 (IFN-gamma and CXCL10) and TH2-like immunity (IL-5, IL-13, CCL17, and CCL22) using ultrasensitive ELISAs. Antigen-presenting cell costimulatory requirements (CD4, HLA-DR, CD80/86, and cytotoxic T lymphocyte-associated antigen 4 [CTLA4] Ig) were determined. RESULTS: T cell-dependent, peanut-specific IL-5, IL-13, and CCL22 were common in peanut-tolerant individuals, regardless of whether they had positive or negative skin test responses. These were blocked by anti-CD4 and were dependent on CD28/CD86 costimulation. None of the 70 individuals studied had demonstrable IFN-gamma or CXCL10 responses to peanut. All demonstrated TH1 and TH2 responses to the ubiquitous recall antigen streptokinase. CONCLUSIONS: Qualitatively similar and quantitatively increasing peanut-specific TH2 responses in the consistent absence of putatively protective TH1 immunity were found in both peanut-tolerant individuals and those with peanut allergy. CLINICAL IMPLICATIONS: The continuum of responses between individuals with negative and individuals with positive skin test results, rather than TH1 versus TH2 bias, might be important in peanut allergy.
- PreMedline Identifier: 17030245
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