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ABSTRACT. Objective. To characterize the features of cold urticaria in children, with particular focus on systemic reactions, because little pediatric data are available.Methodology. Chart reviews of 30 children <18 years old who were evaluated in the past 3 years at the Children's Hospital Allergy Program (Boston, MA) and a private allergy practice. Demographic, diagnostic, and therapeutic data were collected. Telephone interviews of patients and/or their parents were performed to obtain follow-up data.Results. Our data showed that the mean and median ages of onset were ϳ7 years. No secondary causes were found. One third of patients had anaphylactic reactions. These reactions could not be predicted based on available variables. Patients with negative cold-stimulation test (ice-cube challenge) at 10 minutes had similar symptoms and response to antihistamines as those patients with positive ice-cube-challenge test. In addition, our group of patients with cold urticaria had a strikingly high rate of asthma (46.7%) and allergic rhinitis (50%). The rate of family history of atopic diseases was even higher (89.3%).Conclusions. Cold urticaria occurs in children and may be associated with anaphylaxis. In our series, no secondary causes were found. All patients with cold urticaria and their parents should be cautioned regarding the risk of anaphylaxis and provided with an epinephrine autoinjector. Pediatrics 2004;113:e313-e317. URL: http://www.pediatrics.org/cgi/content/full/113/4/e313; cold urticaria, anaphylaxis, cold-stimulation test.ABBREVIATION. H1, histamine 1 receptor. C old urticaria is characterized by the development of urticaria and/or angioedema after cold exposure. 1 It is an uncommon form of physical urticaria and thought to be rare in children. Of patients with cold urticaria, Ͼ90% have idiopathic (essential) cold urticaria. [2][3][4] The remainder are mostly secondary to cryoglobulinemia. A rare form of the disease, known as delayed cold-induced urticaria, is characterized by the delayed expression of urticaria and angioedema 9 to 18 hours after cold exposure. It is probably inherited as an autosomal dominant condition. 5 Another syndrome known as familial cold urticaria is characterized by the development of intermittent rash (not urticaria), fever, arthralgia, and conjunctivitis 2.5 hours after generalized exposure to cold. It is inherited as an autosomal dominant condition. Patients with this syndrome were identified recently to have mutations in chromosome 1q44. 6 The prevalence and course of cold urticaria are not well defined. The most common method to confirm the diagnosis is the ice-cube-challenge test. It entails the application of an ice cube on the skin for nonstandardized time intervals followed by a period of rewarming. Approximately 20% of patients with cold urticaria have a negative ice-cube-challenge test. 4 A serious and interesting feature of cold urticaria is anaphylaxis. It is observed in one third to one half of adult patients. 3,4,7 Anaphylaxis has resulted in several deaths either ...

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INTRODUCTIONSesame seed is an emerging food allergen in the U.S. pediatric population as it becomes more common in the American diet. A recent systematic review of seed allergies described a prevalence of < 1% for sesame allergy as defined by a positive food challenge.1 It has been reported that most patients have sesame allergy before the age of 2 and about 20% of children with clinical allergy eventually develop tolerance.2 Another study described 9 of 30 children (30%) developing tolerance at an average age of 2.8 years.3 Dalal et al. reported anaphylaxis as the presenting symptom in 30% of children with sesame allergy, all occurring in patients less than 1 year of age.4 This is of significant clinical concern in children who are too young to describe their symptoms.Clinical diagnostic tests such as food-specific IgE levels and skin prick test (SPT) results may aid in deciding who will tolerate a food challenge compared to those who are likely to react.5 Diagnostic decision points for food-specific IgE antibodies have been published for common food allergens such as egg, milk, peanut and fish.6 , 7 However, there is conflicting data regarding the diagnostic value of sesame-specific IgE and SPT and currently there are no established thresholds that predict clinical reactivity. Zavalkoff et al. were unable to establish a sesame-specific IgE threshold with a 95% positive predictive value.8 In a paper published by Maloney et al., a fitted predicted probability curve of clinical reactivity to sesame in relation to sesame-specific IgE did not show a 90% or 95% predicted probability of a reaction.9 Lastly, Ho et al. identified a sesame SPT wheal diameter ≥ 8 mm as being predictive of a positive food challenge with > 95% accuracy.10 Oral food challenge was used as the gold standard by which performance characteristics (sensitivity, specificity, positive and negative predictive values) of sesame-specific IgE measurements and SPT wheal size were calculated. Receiver operator characteristic curve (ROC) analysis was utilized to determine a threshold that would differentiate children with true sesame allergy from those who are tolerant. The relationship between sensitization status and outcome measure was analyzed using logistic regression. Fitted predicted probability curves were plotted using the results from logistic regression.Serum samples were analyzed for sesame-specific IgE using an ImmunoCAP fluorescence enzyme immunoassay (Phadia AB, Portage, MI). The detection limit of the assay was 0.35 kU/L. A positive ImmunoCAP test was defined as ≥ 0.35 kU/L.Skin prick tests were performed in a standard fashion using the Multi-Test II device from Alk-Abello (Round Rock, TX) and commercially prepared extract from Greer Laboratories (Lenoir, NC). Negative controls with saline and positive controls with histamine were performed concurrently. The mean of the longest diameter and orthogonal diameter were measured in millimeters at 15 minutes. A positive SPT was defined as a wheal diameter ≥ 3 mm larger than the negative control....

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Background-Children with food allergies often have concurrent asthma.