These findings suggest that sensitisation to Alternaria is frequently expressed by exclusive production of specific IgE in the nasal mucosa. Thus, measuring nasal IgE in children with rhinitis and negative SPT during the period of presence of Alternaria spores seems helpful to avoid a mistaken diagnosis of non-allergic rhinitis.

Atopic dermatitis (AD) is a common, chronic or chronically relapsing, multifactorial skin disease that mainly occurs in children but affects also adults. AD usually begins early in life and often concerns people with a personal or family history of asthma and allergic rhinitis. AD is characterized by eczematous changes in the epidermis and originates from a late, T-cell mediated reaction associated to the formation and production of memory T-cell of TH2 type, occurrence of homing receptor at skin level and cutaneous lymphocyte-associated (CLA) antigens. Extrinsic or allergic AD, but not intrinsic AD, shows high total serum IgE levels and the presence of specific IgE for environmental and food allergens. A pivotal role in the pathogenesis of AD is played by filaggrin, a protein contained in the granular layer of the epidermis regulating the aggregation of keratin filaments. Mutation in the filaggrin gene causes decreased barrier function of the corny layers of the epidermis. This favours the enter through the skin of environmental allergens, especially the house dust mite, that further facilitates such entering by the proteolytic activity of its major allergen Der p 1. In fact, recent advances suggest that the dust mite, more than foods, is the major cause of allergic AD. As far as the causal diagnosis of AD is concerned, there is notable evidence supporting the capacity of the atopy patch test (APT) to reproduce the pathophysiologic events of AD. This makes APT a valuable diagnostic tool for AD.

Obesity is associated with an increased all-cause mortality rate and even small weight losses can be associated with short-term reduction in risk factors for disease. There is strong evidence that weight loss in obese subjects improves risk factors for diabetes and cardiaovascular diseases. Metabolic syndrome (MS) in adults is defined as a cluster of risk factors for cardiovascular disease and type 2 diabetes mellitus, which includes abdominal obesity, dyslipidemia, glucose intolerance and hypertension. Application of the MS concept in children and adolescents is controversial; in fact no consensus exists on a specific definition for pediatric MS. Lack of consensus is in part due to body evolution associated with childhood and puberty that is related to changes in metabolic and clinical characteristics. The aim of this article is to try to clarify the differences between the MS as a concept and the MS as a diagnostic category, as well as to develop a theory related to its pathophysiology. We comment on the relationship between obesity, regional fat distribution and the MS, and finally we offer some insights into MS methodological approaches for estimating metabolic risk-factor clustering in children and adolescents.

The atopy patch test (APT) was recently defined as an important tool in diagnosis of atopic dermatitis (AD) and also of rhinitis and asthma caused by hypersensitivity to the house dust mites. We evaluated 465 children (279 males and 186 females) aged 0.4-17.6 years (mean 6.6 +/- 3.8 years), by dividing them into four groups: group A, current AD (40 patients); group B, current AD with respiratory symptoms (156 patients); group C, past AD with respiratory symptoms (203 patients); and the control group, respiratory symptoms with no history of AD (66 patients). The APT was significantly more frequently positive in groups with current AD (groups A and B) or past AD (group C) than in the control group, while skin prick test (SPT) and radioallergosorbent test (RAST) were significantly more frequently positive in the control group. With multivariate analysis, for APT, significant differences were found in the comparison between group A vs group B (odds ratio (OR) 1.55) and between group A vs group C (OR 1.81). The mean age was significantly lower in group A than in groups B, C, and the control group and with less significance in groups C vs D. Children sensitized to mites with current or past AD, with or without respiratory symptoms, have a different response to diagnostic tests, which is characterized by a highly significantly more frequent positive APT in comparison with subjects who have respiratory symptoms but a negative history for AD, who show the common response to SPT and RAST.

Parental obesity was strictly associated with MetS in all children and should be considered in clinical practice. In older children, wrong lifestyle and dietary habits were related to parental obesity.