Irena Ivković-Jureković

Analysis of biennial outbreak pattern of respiratory syncytial virus according to subtype (A and B) in the Zagreb region

Background:  The epidemic pattern of respiratory syncytial virus (RSV) in Croatia is biennial. In order to determine if the circulation of different RSV subtypes affects the outbreak cycle, the aim of the present study was to analyze the epidemic pattern of RSV in children in Croatia (Zagreb region) over a period of 3 consecutive years.

Oral allergy syndrome in children

Oral allergy syndrome (OAS) is an allergic reaction that occurs after consumption of fresh fruits and vegetables in patients with allergy to pollen. It is mediated by immunoglobulin E (IgE) antibodies and symptoms arise as a result of cross-reactivity between pollen and plant-derived food. OAS is rarely seen in young children, but the prevalence increases with age. The objectives of the study were to identify the prevalence of OAS and probable risk factors in children and adolescents with seasonal allergic rhinitis (AR). One-hundred and twenty patients with seasonal AR were included. Patients were diagnosed based on their clinical history, skin prick test outcome and specific IgE. In patients describing OAS, prick-by-prick tests with fresh fruit or vegetables were carried out. Thirty-two patients had OAS and it was more frequent in female patients than in male patients. OAS was more frequent in adolescents than in small children and in patients with higher total IgE. OAS was significantly more prevalent in patients with AR and asthma (P=0.0016), as was the case in patients with AR and atopic dermatitis (P=0.0004). OAS is rarely diagnosed in small children, partly because of an inadequate clinical history. Patients with OAS may have some risk factors in addition to pollen allergy, and those with more severe atopy are more likely to develop OAS.

Etiology and clinical characteristics of single and multiple respiratory virus infections diagnosed in Croatian children in two respiratory seasons.

The aim of this study was to determine the causative agent of acute respiratory infection (ARI) in hospitalized children, as well as investigate the characteristics of ARIs with single and multiple virus detection in two respiratory seasons. In 2010 and 2015, nasopharyngeal and pharyngeal swabs from a total of 134 children, admitted to the hospital due to ARI, were tested using multiplex PCR. Viral etiology was established in 81.3% of the patients. Coinfection with two viruses was diagnosed in 27.6% of the patients, and concurrent detection of three or more viruses was diagnosed in 12.8% of the patients. The most commonly diagnosed virus in both seasons combined was respiratory syncytial virus (RSV) (28.6%), followed by parainfluenza viruses (PIVs) types 1–3 (18.4%), rhinovirus (HRV) (14.3%), human metapneumovirus (10.1%), adenovirus (AdV) (7.1%), influenza viruses types A and B (4.8%), and coronaviruses (4.2%). In 2015, additional pathogens were investigated with the following detection rate: enterovirus (13.2%), bocavirus (HBoV) (10.5%), PIV-4 (2.6%), and parechovirus (1.3%). There were no statistical differences between single and multiple virus infection regarding patients age, localization of infection, and severity of disease (P > 0.05). AdV, HRV, HBoV, and PIVs were significantly more often detected in multiple virus infections compared to the other respiratory viruses (P < 0.001).

Idiopathic Anaphylaxis and Histamine Intolerance

To the Editor, There has been an increase in the number of pediatric patients with idiopathic anaphylaxis (IA) noted in recent years. IA is a potentially life-threatening syndrome caused by an unknown trigger. It must be properly recognized and treated to prevent a fatal outcome. There have been no previous reports of IA with histamine intolerance (HI) in a pediatric patient. This possible connection of HI with IA requires further investigation. A positive autologous serum skin test (ASST) in our patients with IA—yet with no proof of circulating autoantibodies against IgE and against a subunit of the high-affinity IgE receptor (FceRIa)—points to the possibility of a different cause of autoreactivity. Thus, autoimmunity could be another cause of IA, which, up to now, has not been sufficiently investigated. IA is a systemic syndrome of immediate hypersensitivity caused by the release ofmediators frommast cells and basophils, where the trigger remains unknown. It is a frustrating condition for patients because they have no means of avoiding a potential trigger, and therefore, events occur spontaneously and unprovoked. IA exerts a profound effect on quality of life. The conditionwasfirst described in 1978, byBacal et al. (1), and since then, much has been learned about the diagnosis, classification, and treatment. Atopy is noted in 48–58% of patients (2). IA is more common in adults and in women. Clinical manifestations are the same as in allergen-induced anaphylaxis and include urticaria, angioedema, hypotension, tachycardia, bronchial obstruction, stridor, itchy skin, generalized flushing, nausea, vomiting, diarrhea, dysphagia, dizziness, and loss of consciousness. Patients may have a different combination of these symptoms, but tend to have the same manifestations during repeated episodes. The diagnosis is based on a thorough history and clinical examination, and on eliminating other known causes producing the same clinical picture, such as systemic mastocytosis, carcinoid syndrome, pheochromocytoma, hereditary angioedema, and mast cell activation syndrome (2, 3). Treatment recommendations for patients with IA depend on the frequency and severity of attacks. They must carry epinephrine and learn how to manage an acute attack. We present three patients with recurrent episodes of IA, HI, and positive ASST.

Metal allergy as a late-onset complication of the Nuss procedure in a pediatric patient

We report the case of a 14‐year‐old boy with pectus excavatum who developed a metal allergy to stainless steel bar as a late‐onset complication after the Nuss procedure. He did not have atopic diathesis. Treatment with oral steroids was effective and the metal bar was successfully removed 2 years later.