Allergen-specific immunotherapy: an update on immunological mechanisms of action

Specific immunotherapy (SIT) is the only treatment able to modify the natural history of the allergic subjects. Several aspects of the immunopathological response modified by SIT have been investigated; the first parameter historically studied was the production of allergen-specific antibodies. An increase of allergen-specific IgG4 and a decrease of IgE appear after SIT. A shift from Th2-polarized immune response toward Th1-oriented pattern has been reported after SIT. More recently, a crucial role for a subpopulation of T cells has been evidenced: T regulatory cells (Treg). Allergic patients have a defect of Tregs. SIT is able of inducing a specific Treg response. Sublingual immunotherapy is an alternative route of administration for SIT. Recent evidence shows that SLIT is also able of inducing a Treg response as detected by IL- 10 production

RHINOSINUSITIS AND ASTHMA: A VERY LONG ENGAGEMENT

Upper and lower airways may be considered as a unique entity, interested by coexisting inflammatory processes that share common etiopathogenic mechanisms. Previous studies have strongly demonstrated a relationship between rhinosinusitis and asthma. This has led to the introduction of the concept of "united airways", which has also been included in the WHO document Allergic Rhinitis and its Impact on Asthma (ARIA); this concept has important consequences also on the treatment of these disorders. To better summarize the evident connection between upper and lower airway disease we decided to describe it as a multilayered construction, each level pointing out more deeply the relationship between these entities

Acute Pustular Dermatosis, Following Topical Treatment With Pimecrolimus, in a Child Affected With Atopic and Contact Hand Dermatitis

Atopic dermatitis is considered an important risk factor for chronic hand dermatitis, which can be seen in children too. Pimecrolimus cream 1% is approved to treat atopic dermatitis in children aged 2 years or older. In adults, this drug has been used for some clinical indications other than atopic dermatitis, such as chronic hand dermatitis. Here, we describe an adverse drug reaction in a 2-year-old child affected with atopic dermatitis, who was treated with topical pimecrolimus in order to ameliorate her concomitant hand dermatitis. The use of topical pimecrolimus led to a previously undescribed hand pustular dermatosis, being consistent with a form of pustular leukocytoclastic vasculitis, which required the permanent discontinuation of topical pimecrolimus

Immunoglobulin Production Pattern in Allergic and Non-Allergic Subjects:

Allergic rhinitis (AR) is characterized by Th2 polarized immune response, such as increased IL-4 and reduced IFN-γ production, and by a functional defect of T regulatory cells. This impaired immune response profile influences the pattern of immunoglobulin (Ig) production in allergic patients. However, no studies have compared the pattern of inhalant allergen-specific Ig classes between allergic patients and normal subjects. The aim of this study is to therefore investigate the allergen-specific IgE, IgG, IgG4, and IgA serum level pattern in a group of patients with pollen allergy and in non-allergic healthy subjects. One hundred and two allergic patients (evaluated both out of and in the pollen season) were enrolled. In addition, 50 healthy non-allergic subjects were recruited during the whole year. Serum allergen-specific IgE, IgG, IgG4, and IgA for Parietaria, grasses, and birch were quantitatively determined by the ImmunoCAP System method. Allergen-specific IgE, IgG, IgG4, and IgA serum levels were significantly different for each tested allergen (p=0.0001 for each class) among groups. Allergic patients, mainly during pollen season, showed the highest IgG, IgG4, and IgA levels. The present study therefore provides the preliminary evidence that Ig production pattern toward inhalant allergens may depend on the specificity of the allergenic response both in non-allergic subjects and allergic patients Allergic patients do not show a defect of IgG and IgA classes. In addition, this study is the first that quantitatively evaluates the Ig classes. However, further studies should include non-allergic subjects evaluated both during and out of the pollen season

Antibiotic treatment alone for acute rhinosinusitis gives a poor response in allergic children.

Acute rhinosinusitis (ARS) is frequent in children. Patients with allergic rhinitis show signs of more impaired paranasal sinus functioning than normal subjects during viral colds. This study evaluated the effectiveness of administering antibiotics alone to treat ARS in both allergic and non-allergic children. We obtained informed consent from the parents of each patient enrolled in the study. 97 children, 55 males and 42 females aged between 4 and 9 years (46 of whom were allergic), suffering from ARS, were treated with amoxicilline-clavulanate (50 mg/Kg bid) for 14 days. Symptoms and endoscopic signs of illness were evaluated at baseline and immediately after treatment. Symptoms improved significantly (p<0.001) after treatment in 84 patients, equally distributed between allergic and non-allergic subjects. On the contrary, endoscopic signs disappeared only in 49 children, 9 of whom were allergic (OR 14.9, 95\%CI 4.6-40.1, p<0.001). Slight to fair agreement was observed between clinical symptoms and endoscopic signs (agreement 64\% , Kappa=0.28, McNemar test p<0.001). Antibiotic therapy alone in the treatment of ARS may be generally insufficient to resolve symptoms, mainly endoscopic signs. Moreover, in allergic children this issue appears to be more evident

Sublingual immunotherapy in children: facts and needs

Allergen specific immunotherapy (SIT) is the practice of administering gradually increasing doses of the specific causative allergen to reduce the clinical reactivity of allergic subjects, and is the only treatment targeting the causes of hypersensitivity and not only the symptoms, as done by drugs. The traditional, subcutaneous immunotherapy (SCIT) was burdened by the problem of systemic reactions which may be sometimes severe and - though very rarely - even fatal. This was the background to develop non injections routes for SIT and particularly sublingual immunotherapy (SLIT), that emerged as a real treatment option for respiratory allergy

Food allergy: cause or consequence of pediatric eosinophilic esophagitis? Potential implications of ultraprocessed foods in prevention and management

: Eosinophilic esophagitis (EoE) is a chronic, immune-mediated disease characterized by eosinophilic infiltration, leading to esophageal dysfunction, inflammation, and fibrotic remodeling. In the last few decades, there has been an increased prevalence of EoE at an alarming rate in the pediatric age. The pathogenesis of EoE is still largely undefined, and this limits the definition of effective strategies for the prevention and management of this condition. EoE is considered a multifactorial disease arising from a negative interaction between environmental factors and genetic background, causing an impaired esophageal epithelial barrier with subsequent abnormal allergen exposure activating type 2 (Th2) inflammation. Food antigens have been suggested as key players in Th2 inflammation in pediatric patients with EoE, but emerging evidence suggests a potential role of other dietary factors, including ultraprocessed foods, as possible triggers for the occurrence of EoE. In this paper, we discuss the potential role of these dietary factors in the development of the disease, and we propose a new approach for the management of pediatric patients with EoE

Efficacy of Bacillus clausii spores in the prevention of recurrent respiratory infections in children: a pilot study

Probiotic milk has been previously demonstrated to reduce the number of respiratory infections (RI) among children attending day care centres. Thus, this pilot study was aimed to assess the efficacy and the safety of 3 month treatment with Bacillus clausii in the prevention of recurrent respiratory infections (RRI) in children. Eighty children with RRI were studied: 40 of them were randomly treated with B. clausii for 3 months, and followed up for further 3 months; 40 were included in the control group during the same period. Children treated with B. clausii had shorter duration of RI in comparison with the control group both during the treatment phase (mean 11.7 days vs 14.37; p=0.037) and the follow-up period (mean 6.6 days vs 10.92; p=0.049). This effect was evident also in allergic children during the follow-up. In conclusion, this pilot study provides the first preliminary evidence that B. clausii may exert a significant and persistent impact on RI in children and is safe and well tolerated

An asymptomatic mediastinal cyst in a young child: Case report and summary of the literature

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