Fruit-induced FPIES masquerading as hereditary fructose intolerance.

Hereditary fructose intolerance (HFI) symptoms develop at first introduction of fruit during weaning. We report on an infant with suspected HFI who presented with repeated episodes of vomiting and hypotension after ingestion of fruit-containing meals. The first episode occurred at age 4 months. Despite negative genetic testing for HFI, strict avoidance of fruit ingestion resulted in lack of recurrence of symptoms. Oral-fructose-tolerance testing conducted with an apple mousse did not determine hypoglycemia or fructosuria but caused severe hypotension. Allergy evaluations were negative, and the history was diagnostic for fruit-induced food protein-induced enterocolitis syndrome. Because this non-immunoglobulin E-mediated gastrointestinal food hypersensitivity manifests as profuse, repetitive vomiting, often with diarrhea, leading to acute dehydration and lethargy, it may be misinterpreted as HFI. We advise pediatricians to consider food protein-induced enterocolitis syndrome in the differential diagnosis when there is a suspicion of HFI.

Effects of montelukast treatment and withdrawal on fractional exhaled nitric oxide and lung function in children with asthma.

BACKGROUND: Leukotriene receptor antagonists (LTRAs) reduce fractional exhaled nitric oxide (Feno) concentrations in children with asthma, but the effect of LTRA withdrawal on Feno and lung function is unknown. We aimed to study the effect of treatment and withdrawal of montelukast, a LTRA, on airway inflammation as reflected by Feno and lung function in children with asthma. METHODS: A double-blind, randomized, placebo controlled, parallel group study was undertaken in 14 atopic children with mild persistent asthma who were treated with oral montelukast (5 mg/d for 4 weeks) and 12 atopic children with mild persistent asthma who received matching placebo. A follow-up visit was performed 2 weeks after montelukast or placebo withdrawal. RESULTS: Montelukast reduced Feno concentrations by 17% (p = 0.067), an effect that was more pronounced (35%) [p = 0.0029] when children with seasonal atopy who were exposed to relevant allergens during the treatment phase were excluded from analysis (n = 3). Compared to those at the end of treatment, Feno concentrations were increased 2 weeks after montelukast withdrawal (p = 0.023) concomitant with a reduction in absolute FEV(1) values (p = 0.011), FEV(1) percentage of predicted values (p = 0.006), FEV(1)/FVC ratio (p = 0.002), and forced expiratory flow at 25% to 75% of FVC values (p = 0.021). These changes were not observed in the placebo group. CONCLUSIONS: LTRAs reduce Feno concentrations in children with asthma, and withdrawal can result in increased Feno values and worsening of lung function in children with asthma.

Effects of a leukotriene receptor antagonist on exhaled leukotriene E4 and prostanoids in children with asthma.

BACKGROUND: Leukotriene (LT) E(4) and 8-isoprostane concentrations are elevated in exhaled breath condensate in children with asthma. The effects of leukotriene receptor antagonists (LTRAs) on exhaled leukotriene and prostanoids in children with asthma are unknown. OBJECTIVE: (1) To study the effect of montelukast, a LTRA, on exhaled LTE(4), 8-isoprostane, and prostaglandin E(2) in children with asthma and atopic children; (2) to measure exhaled nitric oxide. METHODS: An open-label study with oral montelukast (5 mg once daily for 4 weeks) was undertaken in 17 atopic children with asthma and 16 atopic children without asthma. RESULTS: Pretreatment exhaled LTE(4) (P < .0001) and 8-isoprostane (P < .0001) values were higher in atopic children with asthma than in atopic children without asthma. In atopic children with asthma, montelukast reduced exhaled LTE(4) by 33% (P < .001), and this reduction was correlated with pretreatment LTE(4) values (r = -0.90; P = .0001). Posttreatment exhaled LTE(4) levels in children with asthma were higher than pretreatment LTE(4) values in atopic children without asthma (P < .004). Montelukast had no effect on exhaled LTE(4) in atopic children without asthma (P = .74), or on exhaled 8-isoprostane (atopic children with asthma, P = .94; atopic children without asthma, P = .55) and PGE(2) (atopic children with asthma, P = .56; atopic children without asthma, P = .93) in both groups. In atopic children with asthma, exhaled nitric oxide concentrations were reduced by 27% (P < .05) after montelukast. CONCLUSION: Leukotriene receptor antagonists decrease exhaled LTE(4) in atopic children with asthma. This reduction is dependent on baseline exhaled LTE(4) values. CLINICAL IMPLICATIONS: Measurement of exhaled LTE(4) might help identify children with asthma most likely to benefit from LTRAs.

Effects of inhaled corticosteroids on exhaled leukotrienes and prostanoids in asthmatic children.

BACKGROUND: Lipid mediators play an important pathophysiologic role in atopic asthmatic children, but their role in the airways of atopic nonasthmatic children is unknown. OBJECTIVE: We sought (1) to measure leukotriene (LT) E 4 , LTB 4 , 8-isoprostane, prostaglandin E 2 , and thromboxane B 2 concentrations in exhaled breath condensate in atopic asthmatic and atopic nonasthmatic children; (2) to measure exhaled nitric oxide (NO) as an independent marker of airway inflammation; and (3) to study the effect of inhaled corticosteroids on exhaled eicosanoids. METHODS: Twenty healthy children, 20 atopic nonasthmatic children, 30 steroid-naive atopic asthmatic children, and 25 atopic asthmatic children receiving inhaled corticosteroids were included in a cross-sectional study. An open-label study with inhaled fluticasone (100 microg twice a day for 4 weeks) was undertaken in 14 steroid-naive atopic asthmatic children. RESULTS: Compared with control subjects, exhaled LTE 4 ( P <.001), LTB 4 ( P <.001), and 8-isoprostane ( P <.001) levels were increased in both steroid-naive and steroid-treated atopic asthmatic children but not in atopic nonasthmatic children (LTE 4 , P=.14; LTB 4 , P=.23; and 8-isoprostane, P=.52). Exhaled NO levels were increased in steroid-naive atopic asthmatic children ( P <.001) and, to a lesser extent, in atopic nonasthmatic children ( P <.01). Inhaled fluticasone reduced exhaled NO (53%, P <.0001) and, to a lesser extent, LTE 4 (18%, P <.01) levels but not LTB 4 , prostaglandin E 2 , or 8-isoprostane levels in steroid-naive asthmatic children. Conclusions Exhaled LTE 4 , LTB 4 , and 8-isoprostane levels are increased in atopic asthmatic children but not in atopic nonasthmatic children. In contrast to exhaled NO, these markers seem to be relatively resistant to inhaled corticosteroids.