Biphasic reactions in children undergoing oral food challenges.

Literature regarding biphasic reactions in the pediatric population is sparse. We aimed to determine the prevalence of biphasic reactions in children with food allergies undergoing oral food challenges (OFCs) and examine whether any clinical or treatment factors are associated with biphasic reactions. A retrospective chart review of OFCs conducted between July 2007 and March 2011 was performed. Charts were reviewed from time of challenge to 48 hours after challenge to capture data on any biphasic reactions. Uniphasic and biphasic reactions were compared in terms of specific clinical features and treatments. Of 614 positive challenges, 9 resulted in a biphasic reaction (1.5%). Six of the biphasic reactions occurred in challenges where the initial reaction met anaphylaxis criteria. The biphasic reactions were to eggs (4), peanuts (3), and milk (2). The symptom-free interval ranged from 2 to 24 hours. There were no statistically significant differences in clinical features between uniphasic and biphasic reactions, but there appeared to be a higher percentage of initial reactions with multiple organ involvement and meeting anaphylaxis criteria in the biphasic group. Biphasic reactors were significantly more likely to have received steroids for their initial reaction. A higher percentage of biphasic reactors also appeared to have received epinephrine, multiple doses of epinephrine, and antihistamines for their initial reactions. Biphasic reactions are rare in children undergoing OFCs and may be associated with more severe allergic reactions. Children with severe reactions may benefit from a 24-hour period of observation.

Asthma and frequency of wheeze: risk factors for the persistence of atopic dermatitis in children.

BACKGROUND: Studies have examined the development of asthma in children with atopic dermatitis (AD); however, none have looked at the association of asthma or the frequency of wheeze with respect to persistence or difficulty in achieving AD clinical improvement in children. OBJECTIVE: To determine whether children with AD who have asthma and increasing frequency of wheezing have more persistent AD. METHODS: This is a cohort study using the Pediatric Eczema Elective Registry (PEER) database, which includes data obtained at enrollment and 3 years later. The AD outcome was the persistence of skin symptoms. Our covariates of interest were asthma diagnosis and wheezing symptoms, which were measured at enrollment and again at year 3 of the study. Multivariate logistic regression models assessed the magnitude of associations among AD symptoms, asthma diagnosis, and the frequency of wheeze. All models were adjusted for sex, age, and ethnicity. RESULTS: A total of 2104 children were enrolled in the PEER study and had at least 3 years of follow-up at the time of this study. At enrollment, an asthma diagnosis decreased the likelihood of being rash free in the preceding 6 months by 30% (odds ratio, 0.70; 95% confidence interval, 0.59-0.84). At year 3, having asthma decreased the likelihood by 40% (odds ratio, 0.60; 95% confidence interval, 0.49-0.72). Increasing frequency of wheezing also decreased the likelihood that a child was rash free (P < .001). CONCLUSION: For children with AD, a history of asthma and an increasing frequency of wheezing correlate strongly with more persistent AD.

Do bugs control our fate? The influence of the microbiome on autoimmunity.

Autoimmune disease has traditionally been thought to be due to the impact of environmental factors on genetically susceptible individuals causing immune dysregulation and loss of tolerance. However, recent literature has highlighted the importance of the microbiome, (a collective genome of microorganisms in a given niche) in immune homeostasis. Increasingly, it has been recognized that disruptions in the commensal microflora may lead to immune dysfunction and autoimmunity. This review summarizes recent studies investigating the interplay between the microbiome and immune-mediated organ-specific diseases. In particular, we review new findings on the role of the microbiome in inflammatory bowel disease, celiac disease, psoriasis, rheumatoid arthritis, type I diabetes, and multiple sclerosis.

Presentation of hemophagocytic lymphohistiocytosis due to a novel MUNC 13-4 mutation masked by partial therapeutic immunosuppression.

Hemophagocytic lymphohistiocytosis is a potentially fatal disease characterized by excessive macrophage and lymphocyte activity. Patients can be affected following immune activation after an oncologic, autoimmune or infectious trigger. An associated gene mutation may be found which impairs cytolytic lymphocyte function. We describe a pediatric case of hemophagocytic lymphohistiocytosis with a novel mutation of MUNC 13-4 whose diagnosis was confounded by concurrent immunosuppression. Clinical reassessment for hemophagocytic lymphohistiocytosis is necessary in persistently febrile patients with laboratory derangements in the setting of immunosuppressive agent exposure.