Abstract
Objective
The objective of the study was to evaluate the role of atopy in otitis media with effusion (OME) in children attending primary school, focusing on the audiometric and tympanometric measurements among atopic and nonatopic subjects suffering from OME.
Materials and Methods
Three hundred ten children (5–6 years old) were screened in Western Sicily by skin tests and divided into atopics (G1) and nonatopics (G2). The samples were evaluated for OME by pneumatic otoscopy, tympanogram, and acoustic reflex tests. The parameters considered were as follows: documented persistent middle ear effusion by otoscopic examination for a minimum of 3 months, presence of B or C tympanogram, absence of ipsilateral acoustic reflex, and a conductive hearing loss greater than 25 dB at any one of the frequencies from 250 Hz through 4 kHz.
Results
The overall prevalence rate of OME was 12.9% (42.85% for G1 and 6.30% for G2, odds ratio = 11.16); OME was bilateral in 28 children (70%). B tympanogram was evidenced in 48 ears (70.59%), with a significative difference between G1 and G2 ( P < .001). The analysis of mean air conduction pure tone (31.97 dB for G1 and 29.8 dB for G2) and of tympanometric measurements such as ear canal volume, tympanometric peak pressure, and static compliance by analysis of variance test showed a significative difference between G1 and G2 ( P < .05).
Conclusions
The higher prevalence of OME in atopic children and the statistically significant differences in audiometric and tympanometric measurements among atopic and nonatopic subjects suffering from OME suggest the important role of allergy in the genesis and recurrence of OME.
1
Introduction
Otitis media with effusion (OME) describes an inflammatory process within the middle ear space that is generally associated with accumulation of fluid and that may lead to hearing loss, learning difficulties, and delay of language development . It is a common disease in children, with an incidence range from 6% to 64%. . Among the major causes of OME is the dysfunction of the eustachian tube that is generally related, in younger children, to upper respiratory tracts infections, adenoid hypertrophy, and craniofacial malformations, such as cleft palate deformities and Down syndrome .
The involvement of immunoglobulin E–mediated allergic reactions in the pathogenesis of OME has been suggested by clinical observations of a high prevalence of OME among patients with allergies . In fact, several studies evidenced that 40% to 50% of children with OME, older than 3 years, had nasal allergy, whereas 21% of allergic children have OME. It is known that middle ear mucosa itself is rarely a target organ for allergy, and the release of biologic mediators of inflammation from basophils and mast cells occurs in the nasal and nasopharyngeal mucosa. These mediators most likely produce eustachian tube edema and inflammation. Over a long period, this chronic inflammatory response, along with viral or bacterial infection, produces middle ear effusion . Even if, in the last years, there was a great consensus among the studies with respect to the role of atopy on OME, the knowledge on the audiological characteristics of OME among atopic and nonatopic subjects is still incomplete.
The aim of this study, carried out on primary schoolchildren aged 5 to 6 years who had undergone skin prick tests, is to evaluate the prevalence of OME among the screened population to determine any difference either in OME incidence or in audiometric and tympanometric measurements between atopic and nonatopic subjects suffering from OME.
2
Materials and methods
This study was carried out by the Department of Audiology, University of Palermo, together with the District of Sciacca, examining a group of children attending primary schools in Sciacca from September 2006 to June 2007. The subject group consisted of 313 patients, 155 boys and 158 girls, ranging from 5 to 6 years of age. The study protocol was fully explained to patients or their guardians, and written informed consent was obtained from each patient. Children with skull-facial malformations, Down syndrome, perforated drums, and ventilation tubes were excluded from the study. At the time of the first screen, all the children underwent skin prick tests and otoscopic examination. Skin tests were performed using 12 common perennial and seasonal allergens: Alternaria , Aspergillus , Cladosporium , Penicillium , ragweed, grass mix, trees mix, cockroach, dust mites, Dermatophagoides farinae and Dermatophagoides pteronyssinus , and cat and dog epithelium. Solutions of histamine and saline were used as positive and negative controls, respectively. The results were evaluated after 10 minutes. Wheals at least 3 mm in diameter greater than wheals at the site of the negative control were considered positive. The children with at least 1 positive skin prick test result to any antigen were classified as atopic and included in group 1 (G1), whereas the children with negative skin prick test results served as nonatopic controls and were included in group 2 (G2). Patients in both groups were evaluated for OME and underwent pneumatic otoscopy. When abnormalities suggestive of OME, which included presence of retracted tympanic membranes, presence of fluid level, bubbles, and hypervascularity, were noted, tympanogram and ipsilateral acoustic reflex were performed. The instrument used was a tympanometry machine, model Amplaid 766 (Biomedica Amplifon, Milano, Italy), with a probe frequency of 220 Hz and an air pressure range of −400 to 100 mm H 2 O with automatic recording. Tympanograms were divided into the following types: type A (+99 to −99 mm H 2 O), type C (>−100 mm H 2 O), and type B (flat curve without peak identification). For ipsilateral acoustic reflex, the same machine was used: an Amplaid 766 with a signal of 105 dB hearing threshold level and pure tone stimulus at 1000 and 2000 Hz. Children with otoscopic appearance of OME and abnormal tympanogram result (type B or C with no stapedial reflex) were regarded as positive screens and given a follow-up appointment within 3 months after the initial screening. The criteria for diagnosis of OME in the study were as follows: documented persistent middle ear effusion by otoscopic examination for a minimum of 3 months, presence of B or C tympanograms, absence of ipsilateral acoustic reflex, and a conductive hearing loss greater than 25 dB at any one of the frequencies from 250 Hz through 4 kHz. Audiogram was performed if the child had a type B or C tympanogram. Audiometric tests were performed using a duly calibrated pure tone audiometer and were applied to each ear at frequencies of 0.5, 1.0, 2.0, and 4.0 kHz. The tympanometry measurements considered for OME population were as follows: ear canal volume (ECV), which is an estimate of the volume of air medial to the probe, which includes the volume between the probe tip and the tympanic membrane; the tympanometric peak pressure (TTP), corresponding to ear canal pressure at which the peak of the C tympanograms occur; and the static compliance (SC), which describes the greatest amount of acoustic energy absorbed by the middle ear system.
For the statistical analysis, the χ 2 test, the odds ratio (OR), the regression analysis, the t test, and the analysis of variance (ANOVA, MathWorks Italia, Torino, Italy) test were calculated using the Matlab computer program.
2
Materials and methods
This study was carried out by the Department of Audiology, University of Palermo, together with the District of Sciacca, examining a group of children attending primary schools in Sciacca from September 2006 to June 2007. The subject group consisted of 313 patients, 155 boys and 158 girls, ranging from 5 to 6 years of age. The study protocol was fully explained to patients or their guardians, and written informed consent was obtained from each patient. Children with skull-facial malformations, Down syndrome, perforated drums, and ventilation tubes were excluded from the study. At the time of the first screen, all the children underwent skin prick tests and otoscopic examination. Skin tests were performed using 12 common perennial and seasonal allergens: Alternaria , Aspergillus , Cladosporium , Penicillium , ragweed, grass mix, trees mix, cockroach, dust mites, Dermatophagoides farinae and Dermatophagoides pteronyssinus , and cat and dog epithelium. Solutions of histamine and saline were used as positive and negative controls, respectively. The results were evaluated after 10 minutes. Wheals at least 3 mm in diameter greater than wheals at the site of the negative control were considered positive. The children with at least 1 positive skin prick test result to any antigen were classified as atopic and included in group 1 (G1), whereas the children with negative skin prick test results served as nonatopic controls and were included in group 2 (G2). Patients in both groups were evaluated for OME and underwent pneumatic otoscopy. When abnormalities suggestive of OME, which included presence of retracted tympanic membranes, presence of fluid level, bubbles, and hypervascularity, were noted, tympanogram and ipsilateral acoustic reflex were performed. The instrument used was a tympanometry machine, model Amplaid 766 (Biomedica Amplifon, Milano, Italy), with a probe frequency of 220 Hz and an air pressure range of −400 to 100 mm H 2 O with automatic recording. Tympanograms were divided into the following types: type A (+99 to −99 mm H 2 O), type C (>−100 mm H 2 O), and type B (flat curve without peak identification). For ipsilateral acoustic reflex, the same machine was used: an Amplaid 766 with a signal of 105 dB hearing threshold level and pure tone stimulus at 1000 and 2000 Hz. Children with otoscopic appearance of OME and abnormal tympanogram result (type B or C with no stapedial reflex) were regarded as positive screens and given a follow-up appointment within 3 months after the initial screening. The criteria for diagnosis of OME in the study were as follows: documented persistent middle ear effusion by otoscopic examination for a minimum of 3 months, presence of B or C tympanograms, absence of ipsilateral acoustic reflex, and a conductive hearing loss greater than 25 dB at any one of the frequencies from 250 Hz through 4 kHz. Audiogram was performed if the child had a type B or C tympanogram. Audiometric tests were performed using a duly calibrated pure tone audiometer and were applied to each ear at frequencies of 0.5, 1.0, 2.0, and 4.0 kHz. The tympanometry measurements considered for OME population were as follows: ear canal volume (ECV), which is an estimate of the volume of air medial to the probe, which includes the volume between the probe tip and the tympanic membrane; the tympanometric peak pressure (TTP), corresponding to ear canal pressure at which the peak of the C tympanograms occur; and the static compliance (SC), which describes the greatest amount of acoustic energy absorbed by the middle ear system.
For the statistical analysis, the χ 2 test, the odds ratio (OR), the regression analysis, the t test, and the analysis of variance (ANOVA, MathWorks Italia, Torino, Italy) test were calculated using the Matlab computer program.
3
Results
The total number of children examined was 313, but 3 children were excluded from the study because of skull-facial malformations and perforated drums. A total of 310 children were analyzed. The age of children ranged from 5 to 6 years, with a mean age of 5.56 years (5.59 ± 0.49 for male and 5.53 ± 0.50 for female). Of the children, 155 (50%) were boys and 155 were girls.
At the time of the first examination, based on skin tests, children were classified in 2 groups: G1 (atopics), which included 56 children (18.06%) with positive skin test results, and G2 (nonatopics), which included 254 controls (81.94%) with negative skin test results.
Of the 56 children in G1, 29 patients (51.78%) had positive skin test results for both inhalant and food allergens, 17 patients (30.36%) had a positive test result only for food allergy, and 10 (17.86%) patients had an allergy only against inhalant allergens.
During pneumatic otoscopy, a total of 44 children were found to be suspicious of OME. Of these, 4 had no evidence of OME in the follow-up appointment after 3 months and were excluded from the study. A total number of 40 children (overall prevalence rate of 12.9%) were studied with persistent OME (≥3 months). Of children with OME, 12 were boys and 28 were girls.
Of the 40 children with OME, 24 (60%) were atopic (G1), whereas 16 (40%) were nonatopic (G2) ( Fig. 1 ).
