In this issue

There is considerable interest in the impact of early life nutrition on susceptibility to allergy. Much focus has been on the balance of omega-3 (n-3) and omega-6 (n-6) essential polyunsaturated fatty acids. Indeed we have published a number of papers on this topic. Supplementation of the diet of rats during pregnancy and lactation certainly changes the immune response of the offspring with increased generation of the regulatory cytokine transforming growth factor beta (1). The very large 1 Prevention and Incidence of Asthma and Mite Allergy (PIAMA) study could not show any differences in n-3 and n-6 fatty acids in the breast milk of allergic vs. non-allergic mothers (2). However, the study published in this issue shows that there are indeed differences in the fatty acid profiles of breast milk from mothers whose infants subsequently develop non-atopic eczema. There was no difference in relation to allergy alone or to atopic eczema. Is this a direct effect of altered fatty acid composition on the skin rather than on systemic immune responses? Levels of neopterin are assumed to be an indirect measure of levels of c-interferon (IFN-c) and therefore, might be a useful marker of susceptibility to allergy. This was the basis of a birth cohort study from Austria measuring cord blood neopterin and subsequently urinary neopterin at 6 yr of age. 2 Cord blood levels were of little use in predicting atopic disease. However, it is important to note that the diagnosis of atopy was based exclusively on the ISAAC questionnaire with no direct testing for atopy. Furthermore, it may only be possible to demonstrate deficiency of IFN-c and therefore, neopterin after stimulation of cord blood cells with relevant mitogens or allergens. There remains a question mark over immune deviation and the hygiene hypothesis (3). However, we have published many papers suggesting that pet ownership and/or exposure to endotoxin in early life might reduce risks of atopy. The most recent paper came again from the PIAMA study (4). However, we have two papers on this topic. The first from Cyprus suggests that while exposure to housemite increases mite sensitization, there is no association between cat and dog exposure and sensitization. Furthermore, endotoxin exposure was associated with an increased risk of sensitization. This is based on a rather selected population of self-reported asthmatics compared with controls. It is, however, possible that different genetic factors are operative in Cypriot communities which abrogate the effect of exposure to endotoxin. The second study comes from Japan and suggests a lowering of the prevalence of atopic eczema, allergic rhinitis and cedar pollinosis in children of families who are current cat owners. Passive exposure to smoking also reduced allergic rhinitis and cedar pollinosis. This is not totally inconsistent with a study from Sweden showing a negative association between maternal smoking and atopy in the offspring though a positive association with paternal smoking and atopy (5). Bronchiolitis has been the subject of a number of recent publications (6, 7). We publish here a study showing that blood and sputum eosinophilia during 3 respiratory syncytial virus (RSV) bronchiolitis does not predict subsequent wheezing. However, there were some interesting gender-specific differences in the sputum cell profiles. In allergy-prone mice, RSV infection increased cysteinyl leukotriene generation (8). In contrast, our current paper in virus-associated infant wheeze, high levels of urinary prostaglandin F2 and leukotriene E4 were associated with persistent wheezing only in those infants who did not have RSV infection at admission. Maybe this is more in keeping with the Henderson study (7) which suggested that RSV bronchiolitis was not associated with a subsequent higher risk of atopy. Ketotifen, like many other antihistamines, has additional anti-allergic properties. A murine study from Israel has shown that this drug can abrogate mast cell degranulation in the middle ear and might have a role in the treatment of middle ear disease. In a second study on 2to 6yr-old children, both montelukast and cetirizine were effective in improving perennial allergic Pediatr Allergy Immunol 2006: 17: 2–3