A new method for identifying outlying subsets of data

In various branches of science, e.g. medicine, economics, sociology, it is necessary to identify or detect outlying subsets of data. Suppose that the set of data is partitioned into many relatively small subsets and we have some reason to suspect that one or several of these subsets may be atypical or aberrant. We propose applying a new measure of separability, based on the ideas borrowed from the discriminant analysis. In our paper we define two versions of this measure, both using a jacknife, leave-one-out, estimator of classification error. If a suspected subset is significantly well separated from the main bulk of data, then we regard it as outlying. The usefulness of our algorithm is illustrated on a set of medical data collected in a large survey "Epidemiology of Allergic Diseases in Poland" (ECAP). We also tested our method on artificial data sets and on the classical IRIS data set. For a comparison, we report the results of a homogeneity test of Bartoszyński, Pearl and Lawrence, applied to the same data sets

The Prevalence of Asthma and Declared Asthma in Poland on the Basis of ECAP Survey Using Correspondence Analysis

Results of epidemiological and public health surveys are often presented in the form of cross-classification tables. It is sometimes difficult to analyze data described in this way and to understand relations between variables. Graphical methods such as correspondence analysis are more convenient and useful. Our paper describes an application of correspondence analysis to epidemiological research. We apply the basic concepts of correspondence analysis like profiles, chi-square distance to medical data concerning prevalence of asthma. We aim at describing the relationship between asthma, region, and age. The data presented in this paper come from Epidemiology of Allergy in Poland (ECAP) survey in years 2006–2008. Correspondence analysis shows that there is a fundamental difference in the structure of age groups for people with symptoms compared to those who have declared asthma (regardless of the level of symptoms of asthma and the level of declaration). The variable which best differentiates declared asthma in all regions is “wheezing and whistling.” Correspondence analysis also shows significant differences between locations. Our analyses are performed in the R package “ca”

Oral and nasal provocation test in chicken egg allergy—case report

Abstract Introduction Allergy to chicken egg protein is a common form of food allergy. The most common clinical presentation includes gastrointestinal, skin, and respiratory symptoms. Differential diagnosis, including provocative tests, is critical in diagnosis. Case description We present a case of a 21-year-old patient with egg allergy, who underwent a double-blind food provocation test with placebo (evaluating subjective complaints from the gastrointestinal tract) and a titrated nasal provocation test using dry chicken egg content. We assessed the response of the nasal mucosa in the provocation test using the visual analogue scale (VAS), acoustic and optical rhinometry, as well as measurements of nitric oxide concentration in the exhaled air. During the provocation test, we measured the changes in the transverse section of the nasal passages, which were accompanied by subjective complaints measured with the VAS scale, using objective techniques. In the nasal provocation test with a dose of 20 µg of chicken egg protein, we observed an increase in the reactivity of the nasal mucosa and a decrease in the level of nitric oxide in the exhaled air from the upper airways (920 ppb before the provocation test and up to 867 ppb during the early stage of the allergic reaction). During the provocation tests, we recorded typical symptoms associated with the early stage of the allergic reaction; including nasal obstruction (1.2 cm), leakage of watery discharge (0.8 cm) in the food test, and itchy nose (1.1 cm) in the food test vs. the nasal test: 4.6, 2.8, and 3.5 cm, respectively. Conclusions The nasal mucosa provides convenient conditions for evaluation of the severity of allergy to common food allergens, including chicken egg allergens

A case of lymphocytic esophagitis in a woman with multiple allergies

Abstract Background Lymphocytic esophagitis is a newly recognized entity of unknown origin. Dysphagia is defined as difficulty swallowing and represents a common symptom in the general population with a prevalence of approximately 20%. Chronic inflammation of the esophageal wall may manifest itself clinically and endoscopically, mimicking inflammation of another origin. However, little is known about the pathogenesis of the disease, as patients are seldom suspected and rarely diagnosed with lymphocytic esophagitis. Case presentation Here, we present a rare case of lymphocytic esophagitis in a patient with multiple allergies and suspected eosinophilic esophagitis. A 28-year-old woman with polyvalent sensitization to food and inhalant allergens presented with intermittent dysphagia, a sensation of a foreign body in the throat, itchiness of the oral cavity after ingesting certain foods, heartburn, and prolonged chewing time. A skin prick test showed positive results for birch-tree, alder, hazel, and rye pollen, as well as house dust mites. Apart from obesity (BMI 30 kg/m2), multiple pustules and excoriations on the skin, her physical examination was insignificant. Esophagogastroduodenoscopy (EGD) was performed revealing full-length but discrete trachealization of the esophagus. A barium swallow test showed slowing of esophageal peristalsis in the recumbent position. No esophageal pathology was observed. A histopathological analysis of mucosal samples revealed slight hyperplasia of the basal layer of the esophagus, and the stomach showed changes typical of chronic gastritis. Conclusions In summary, this clinical case illustrates that lymphocytic esophagitis, as a newly recognized entity, should be considered in the differential diagnosis of chronic dysphagia. Additionally, when treating allergic patients, clinicians should be aware that lymphocytic esophagitis, distinct from eosinophilic esophagitis, should be considered in the diagnosis of patients with atopy and upper gastrointestinal symptoms