How common is otogenic meningitis? A retrospective study in southern Sweden over 18 years.

BACKGROUND: Bacterial meningitis is a rare, but life-threatening disease, which sometimes occurs as a complication to acute otitis media (AOM). The proportion of meningitis cases originating from AOM is not clear. PURPOSE: The aim of this study was to investigate the proportion of meningitis cases caused by AOM, to compare risk factors, bacteriology and outcome between otogenic and non-otogenic meningitis, and to analyse the incidence of bacterial meningitis after the introduction of conjugate pneumococcal vaccines (PCV). METHODS: The medical charts of all patients admitted to hospitals in southern Sweden with bacterial meningitis between 2000 and 2017 were retrieved. Based on otoscopy and/or imaging, the proportion of otogenic meningitis cases was calculated, as were annual incidences. RESULTS: A total of 216 patients were identified, 25 of whom died. The proportion of otogenic meningitis was 31% but varied from 6% among teenagers to 40% among adults. Before PCV, 23% of all meningitis cases were children < 2 years, compared to 1% post-PCV. The average incidence in the adult population, on the other hand, increased post-PCV, though there were large annual variations. S. pneumoniae was the most commonly identified pathogen in everyone but teenagers, in whom N. meningitidis was predominant. CONCLUSION: AOM is an important cause of meningitis in children and adults. Though bacterial meningitis almost disappeared in children < 2 years after the introduction of PCV, the incidence of pneumococcal meningitis in adults seems to have increased.

Hearing loss after bacterial meningitis, a retrospective study.

BACKGROUND: Hearing loss is a common sequela after bacterial meningitis, but risk factors for this are poorly studied, particularly in relation to concurrent acute otitis media (AOM). AIMS: The aim of this study was to investigate incidence and risk factors for hearing loss in patients treated for bacterial meningitis. METHODS: In this retrospective study, medical records for patients admitted to hospital with bacterial meningitis in Skåne county, Sweden, between 2000 and 2017 were retrieved. The association between risk factors and hearing loss was estimated using logistic regression. RESULTS: During the 18 years, 187 cases of meningitis were identified. Hearing loss was confirmed in 71 of the 119 patients who had done an audiometry. It was significantly more common in adults. There was also evidence of an association between hearing loss and AOM, and between hearing loss and pneumococcal infection. CONCLUSION: Age, concurrent AOM and pneumococcal infection were risk factors for developing hearing loss. Despite being recommended in the national guidelines, more than a third of the patients had not done a hearing test after recovering from bacterial meningitis. The findings strengthen the demand for prompt ear examination and - if needed - tympanocentesis in meningitis patients.

Nasopharyngeal cultures in children with AOM - A retrospective study on bacteriological findings and impact on management.

BACKGROUND: Despite a far from perfect correlation with middle ear growth, nasopharyngeal cultures are sometimes used in children with acute otitis media (AOM) in order to have some idea of the causative pathogen. How these cultures are used in clinical practice and to what extent they influence clinical management has not previously been studied. The objective with this study was to investigate in what circumstances nasopharyngeal cultures are performed in children with AOM, what the bacteriological results are and to what extent cultures influence clinical management. METHODS: All nasopharyngeal cultures taken in clinical practice from children with AOM in the county of Skåne, Sweden, during 2017-2018 were retrieved together with details from the medical charts two months prior to and one month after the culture. Information about the reason for culturing, the bacteriological result, and whether this result changed the management of the child, was retrieved from the charts. RESULTS: During the 2 years, 978 nasopharyngeal cultures were taken in children with AOM. The most common reasons for obtaining a culture was a recurrence of AOM (40%) or treatment failure (22%). Many of the children had ongoing or recent antibiotic treatment. M. catarrhalis was the most commonly identified pathogen (53%), followed by H. influenzae (30%) and S. pneumoniae (14%). Resistance rates were low, and the most commonly identified resistant pathogen was betalactamase-negative ampicillin-resistant H. influenzae. One in five cultures led to a change in management, such as a change of antibiotics or an additional check-up. This was most commonly seen in association with H. influenzae, reflecting clinical practice in Sweden, where AOM is primarily treated with penicillin V. CONCLUSION: Despite not having a perfect correlation with middle ear growth, nasopharyngeal cultures can provide clues about suitable alternative antibiotics in cases of treatment failure, and they can help monitoring nasopharyngeal carriage and resistance rates.

International registry of otolaryngologist-head and neck surgeons with COVID-19.

BACKGROUND: It has become clear that healthcare workers are at high risk, and otolaryngology has been theorized to be among the highest risk specialties for coronavirus disease 2019 (COVID-19). The purpose of this study was to detail the international impact of COVID-19 among otolaryngologists, and to identify instructional cases. METHODS: Country representatives of the Young Otolaryngologists-International Federation of Otolaryngologic Societies (YO-IFOS) surveyed otolaryngologists through various channels. Nationwide surveys were distributed in 19 countries. The gray literature and social media channels were searched to identify reported deaths of otolaryngologists from COVID-19. RESULTS: A total of 361 otolaryngologists were identified to have had COVID-19, and data for 325 surgeons was available for analysis. The age range was 25 to 84 years, with one-half under the age of 44 years. There were 24 deaths in the study period, with 83% over age 55 years. Source of infection was likely clinical activity in 175 (54%) cases. Prolonged exposure to a colleague was the source for 37 (11%) surgeons. Six instructional cases were identified where infections occurred during the performance of aerosol-generating operations (tracheostomy, mastoidectomy, epistaxis control, dacryocystorhinostomy, and translabyrinthine resection). In 3 of these cases, multiple operating room attendees were infected, and in 2, the surgeon succumbed to complications of COVID-19. CONCLUSION: The etiology of reported cases within the otolaryngology community appear to stem equally from clinical activity and community spread. Multiple procedures performed by otolaryngologists are aerosol-generating procedures (AGPs) and great care should be taken to protect the surgical team before, during, and after these operations.

Panel 1: Biotechnology, biomedical engineering and new models of otitis media.

OBJECTIVE: To summarize recently published key articles on the topics of biomedical engineering, biotechnology and new models in relation to otitis media (OM). DATA SOURCES: Electronic databases: PubMed, Ovid Medline, Cochrane Library and Clinical Evidence (BMJ Publishing). REVIEW METHODS: Articles on biomedical engineering, biotechnology, material science, mechanical and animal models in OM published between May 2015 and May 2019 were identified and subjected to review. A total of 132 articles were ultimately included. RESULTS: New imaging technologies for the tympanic membrane (TM) and the middle ear cavity are being developed to assess TM thickness, identify biofilms and differentiate types of middle ear effusions. Artificial intelligence (AI) has been applied to train software programs to diagnose OM with a high degree of certainty. Genetically modified mice models for OM have further investigated what predisposes some individuals to OM and consequent hearing loss. New vaccine candidates protecting against major otopathogens are being explored and developed, especially combined vaccines, targeting more than one pathogen. Transcutaneous vaccination against non-typeable Haemophilus influenzae has been successfully tried in a chinchilla model. In terms of treatment, novel technologies for trans-tympanic drug delivery are entering the clinical domain. Various growth factors and grafting materials aimed at improving healing of TM perforations show promising results in animal models. CONCLUSION: New technologies and AI applications to improve the diagnosis of OM have shown promise in pre-clinical models and are gradually entering the clinical domain. So are novel vaccines and drug delivery approaches that may allow local treatment of OM. IMPLICATIONS FOR PRACTICE: New diagnostic methods, potential vaccine candidates and the novel trans-tympanic drug delivery show promising results, but are not yet adapted to clinical use.

Panel 2- recent advance in otitis media bioinformatics.

OBJECTIVES: To update the medical literature on recent large-scale studies employing bioinformatics data analysis tools in otitis media (OM) disease models with a principal focus on developments in the past 5 years. DATA SOURCES: Pubmed indexed peer-reviewed articles. REVIEW METHODS: Comprehensive review of the literature using the following search terms: 'genomics, inflammasome, microRNA, proteomics, transcriptome, bioinformatics' with the term 'otitis media', and 'middle ear'. Included articles published in the English language from January 1, 2015-April 1, 2019. IMPLICATIONS FOR PRACTICE: Large scale bioinformatics tools over the past five years lend credence to the paradigm of innate immune response playing a critical role in host defense against bacteria contributing to Otitis Media (OM) progression from acute to chronic. In total, genomic, miRNAomic, and proteomic analyses all point to the need for a tightly regulated innate immune and inflammatory response in the middle ear. Currently, there is an urgent need for developing novel therapeutic strategies to control immunopathology and tissue damage, improve hearing and enhance host defense for both acute and chronic OM based on full understanding of the basic molecular pathogenesis of OM.

Nasopharyngeal cultures in children; when, what and why?

INTRODUCTION: Nasopharyngeal cultures are commonly used to determine the causative bacteria in upper airway infections. However, several bacteria can occupy the nasopharynx simultaneously and most healthy children are asymptomatic carriers of presumptive pathogens. This makes the interpretation of nasopharyngeal cultures difficult. Knowledge about which bacteria reside in the nasopharynx can assist the physician in the choice of antibiotic treatment and might also predict the risk of complications. Today, little is known about how nasopharyngeal cultures are being used in clinical practice. OBJECTIVES: The aim of this study was to explore how nasopharyngeal cultures are used in clinical practice, when and why they are performed, what they show, and what impact they have on the treatment of the patient. METHODS: The results of all nasopharyngeal cultures taken from children aged 0-12 years in the county of Skåne, Sweden, during 2018 were obtained. Medical charts from hospitals and primary care centres were used to determine why the cultures were taken and whether they resulted in a change of treatment. RESULTS: During 2018, 2200 nasopharyngeal cultures were taken, most of them during the winter season. Forty-one percent of children had on-going antibiotic treatment or had been treated with antibiotics in the previous two months. Acute otitis media (AOM) was the most common reason for taking a culture. The most frequently identified bacteria were Moraxella catarrhalis and Haemophilus influenzae. There was a positive correlation between M. catarrhalis on one hand and Streptococcus pneumoniae and H. influenzae on the other. Overall, bacterial resistance was rare. The presence of beta-lactamase negative ampicillin resistant H. influenzae was associated with recent or on-going antibiotics, whereas S. pneumoniae with decreased penicillin susceptibility were found less frequently in the same group of children. A positive culture resulted in a change of treatment in 29% of the cases. CONCLUSION: Apart from playing a confirmatory role and monitoring the incidence of resistant bacteria, almost a third of the nasopharyngeal cultures analysed in this study contributed to decision-making. It therefore appears that bacterial sampling have a role in clinical practice. It would be valuable to study more closely why nasopharyngeal cultures are taken in during AOM and how the result affects the treatment.

Panel 8: Report on Recent Advances in Molecular and Cellular Biochemistry.

Objectives To update the medical literature on recent cellular and molecular advances in otitis media disease models with a principal focus on developments in the past 5 years. We also aim to explain recent translational advances in cellular and molecular biology that have influenced our understanding and management of otitis media. Data Sources PubMed-indexed peer-reviewed articles. Review Methods A comprehensive review of the literature was conducted with the term otitis media and the following search terms: molecular biology, cell biology, innate immunity, oxidative stress, mucins, molecular diagnostics. Included articles were published in the English language from January 1, 2010, to July 31, 2015. Implications for Practice The molecular understanding of otitis media disease progression has rapidly advanced over the last 5 years. The roles of inflammation, mucins, and cell signaling mechanisms have been elucidated and defined. Advances in the field provide a plethora of opportunities for innovative molecular targeting in the development of novel therapeutic strategies for otitis media.

Individual-level effects of antibiotics on colonizing otitis pathogens in the nasopharynx.

BACKGROUND: Although there is evidence of an association between antibiotic consumption and resistant bacteria on a population level, the relationship on an individual level has been less well studied, particularly in terms of nasopharyngeal colonization. We have therefore analysed this association, using data from a closely followed cohort of children taking part in a vaccination trial. METHODS: 109 children with early onset of acute otitis media (AOM) were randomised to heptavalent pneumococcal conjugate vaccine (PCV7) or no vaccination. They were followed for three years with scheduled appointments as well as sick visits. Nasopharyngeal cultures were obtained at all visits. Antibiotic treatments were recorded, as were risk factors for AOM, including siblings, short breast-feeding and parental smoking. Data were entered into a Cox regression model, and the findings of Streptococcus pneumoniae and Haemophilus influenzae with reduced susceptibility to the penicillin group were related to the number of previous courses of antibiotics. RESULTS: There was evidence of an association between the amount of previously consumed betalactams and colonization with beta-lactamasenegative ampicillin-resistant (BLNAR) H. influenzae (RR 1.21; 95% CI 1.03-1.43; p = 0.03), and also with the most commonly prescribed drug; amoxicillin (RR 1.39; 95% CI 1.09-1.76; p = 0.01). There was no evidence for an association between antibiotic consumption and betalactamase producing H. influenzae or S. pneumoniae with reduced susceptibility to penicillin. Furthermore, there was no evidence of an association between resistant bacteria and AOM risk factors or PCV7. CONCLUSION: In this subgroup of children, most of whom were given several courses of antibiotics in early childhood, there was evidence of an association between betalactam/amoxicillin consumption and nasopharyngeal colonization with BLNAR strains, bacteria that have increased in prevalence during the last 10-15 years, and that are notoriously difficult to treat with oral antibiotics.

Subperiosteal abscesses in acute mastoiditis in 115 Swedish children.

OBJECTIVES: To study the outcome of different surgical methods of treating subperiosteal abscesses resulting from acute mastoiditis. METHODS: Medical records for all children from a Swedish retrospective multicentre study, conducted between 1993 and 2007, with acute mastoiditis and subperiosteal abscess, but without predisposing diseases or other complications, were studied. A total of 115 children aged 0-16 years were identified. All patients had received intravenous antibiotics and most had undergone myringotomy. RESULTS: Thirty-three children had been treated with only minor interventions such as retroauricular needle aspiration and/or incision, while 67 had undergone mastoidectomy. Fifteen had undergone both needle aspiration and mastoidectomy. The group treated with needle aspiration/incision was compared with those treated with mastoidectomy. One of the few significant differences found between the groups was a longer hospital stay in the group that had undergone mastoidectomy. CONCLUSIONS: Retroauricular needle aspiration and/or incision combined with intravenous antibiotics and myringotomy was an effective first-line treatment for subperiosteal abscesses resulting from acute mastoiditis. In this retrospective study, no greater risk of further complications was seen in this group compared to the group in which mastoidectomy was performed.

Effect of pneumococcal conjugate vaccination on nasopharyngeal carriage in children with early onset of acute otitis media - a randomized controlled trial.

CONCLUSION: Although children vaccinated with heptavalent pneumococcal conjugate vaccine (PCV) had fewer episodes of acute otitis media (AOM), this trial was unable to prove a simultaneous decrease in nasopharyngeal carriage. OBJECTIVE: Carriage rates of AOM pathogens in the nasopharynx are high among children, and colonization is the first step towards infection. The possible impact of PCV on carriage is therefore of interest, particularly in children with recurrent AOM. The aims of this study were to examine the effect of heptavalent PCV on carriage of AOM pathogens in children at high risk of developing recurrent disease, and to monitor carriage of resistant pathogens in vaccinated and unvaccinated children. METHODS: A total of 109 children with an onset of AOM before 6 months of age, 89 of whom developed recurrent disease, were enrolled in a trial. Fifty-two children were vaccinated and all were closely monitored for 3 years. RESULTS: There was no difference statistically between vaccinated children and controls concerning the carriage of any of the major AOM pathogens. There was evidence of within-child clustering for S. pneumoniae (p = 0.002) and H. influenzae (p < 0.001), indicating that children continued to carry either species over time. Resistance rates were generally low and comparable with national levels.

Immunologic findings in young children with early onset of acute otitis media.

CONCLUSION: No significant differences in the number of immune aberrations were seen between children with or without severe recurrent acute otitis media (rAOM); however, subnormal values of immunological markers were found more often than expected, and 4 of the 60 children had treatment-requiring immune deficiencies. OBJECTIVE: Minor immunologic aberrations have been reported to be more frequent in children with rAOM. Immune investigation is recommended in children with severe rAOM, defined as six or more AOM episodes per year. The purpose of this study was to describe immunological findings in young children at high risk of developing rAOM, and to relate these to the number of expected aberrations and to the presence of severe rAOM. METHODS: A total of 109 children at risk of developing rAOM were offered immune investigation including complement function, immunoglobulins with subclasses and cellular immunity. RESULTS: Sixty patients were tested, 31 of whom had severe rAOM and 12 of whom did not develop rAOM. Low levels of IgG2 (27%), C1q (31%) and mannan-binding lectin (21%) were found up to eight times as often as expected. Although subnormal values were more frequent among children with severe rAOM, the study was too small to provide reliable evidence of any difference. Four children were diagnosed with immune deficiencies that required treatment.

Amphiphilic γ-PGA nanoparticles administered on rat middle ear mucosa produce adjuvant-like immunostimulation in vivo.

CONCLUSION: Amphiphilic biodegradable nanoparticles (NPs) composed of poly(γ-glutamic acid) conjugated with L-phenylalanine ethylester (γ-PGA-Phe NPs) applied on the rat middle ear mucosa produce an inflammatory type 1 response. The observation is of relevance for the use of γ-PGA-Phe NPs as a concomitant antigen delivery system and adjuvant measure in the context of vaccinations. OBJECTIVES: To examine effects of topical mucosal administration of γ-PGA-Phe NPs as a potentially combined antigen delivery system and adjuvant. METHODS: γ-PGA-Phe NPs were administered on rat middle ear mucosa in a sham-controlled design and the response was monitored, focusing on soluble markers in mucosal surface liquids and on overall histopathology. RESULTS: γ-PGA-Phe NPs produced a dose- and time-dependent inflammatory response characterized by generation of proinflammatory cytokines (IL-1α, IL-1ß, IL-6, MIP-1α, and TNF-α) and associated histopathological changes.

Risk factors for carriage of AOM pathogens during the first 3 years of life in children with early onset of acute otitis media.

CONCLUSION: Risk factors associated with increased carriage rates are the same in children with recurrent acute otitis media (rAOM) as in healthy children. These are also known to be risk factors for the development of AOM itself. OBJECTIVES: The aim of this study was to describe risk factors for nasopharyngeal carriage in a cohort of young children at high risk of developing rAOM. METHODS: Children with an onset of AOM before 6 months of age, indicating an 80% risk of developing rAOM, were enrolled in a vaccination trial on heptavalent PCV. These children were monitored for 3 years during healthy and AOM periods with nasopharyngeal cultures, physical examinations, and questionnaires. RESULTS: A total of 109 children were included at a mean age of 5 months; 105 were followed for 3 years, 89 (82%) of whom developed rAOM. Risk factors associated with increased carriage of all major AOM pathogens were age <2 years, concurrent AOM, and fulfilment of rAOM criteria. Having siblings in day care was associated with increased carriage of Streptococcus pneumoniae and Haemophilus influenzae, recent antibiotic treatment was associated with H. influenzae and Moraxella catarrhalis carriage, and winter season was associated with M. catarrhalis carriage alone.

Panel 3: Recent advances in anatomy, pathology, and cell biology in relation to otitis media pathogenesis.

BACKGROUND AND OBJECTIVES: The pathogenesis of otitis media (OM) involves a number of factors related to the anatomy, pathology, and cell biology of the middle ear, the mastoid, the Eustachian tube, and the nasopharynx. Although some issues of pathogenesis are fairly well established, others are only marginally indicated by current knowledge, and yet others remain undisclosed. The objective of this article is to provide a state-of-the-art review on recent scientific achievements in the pathogenesis of OM, as related to anatomy, pathology, and cell biology. DATA SOURCES: PubMed, Ovid Medline, and Cochrane Library. REVIEW METHODS: Articles published on the pathogenesis of OM and the anatomy, pathology, and cell biology of the middle ear, the mastoid, the Eustachian tube, and the nasopharynx between January 2007 and June 2011 were identified. Among almost 1900 abstracts, the authors selected 130 articles for full article review and inclusion in this report. RESULTS: New knowledge on a number of issues emerged, including cell-specific expression and function of fluid transportation and innate immune system molecules, mucous cell metaplasia, mucin expression, bacterial adherence, and epithelial internalization, as well as the occurrence, composition, dynamics, and potential role of bacterial biofilm. In addition, the potential role of gastroesophageal reflux disease and cigarette smoke exposure has been explored further. CONCLUSIONS AND IMPLICATIONS FOR PRACTICE: Over the past 4 years, considerable scientific progress has been made on the pathogenesis of OM, as related to issues of anatomy, pathology, and cell biology. Based on these new achievements and a sustained lack of essential knowledge, suggestions for future research are outlined.

Panel 4: Recent advances in otitis media in molecular biology, biochemistry, genetics, and animal models.

BACKGROUND: Otitis media (OM) is the most common childhood bacterial infection and also the leading cause of conductive hearing loss in children. Currently, there is an urgent need for developing novel therapeutic agents for treating OM based on full understanding of molecular pathogenesis in the areas of molecular biology, biochemistry, genetics, and animal model studies in OM. OBJECTIVE: To provide a state-of-the-art review concerning recent advances in OM in the areas of molecular biology, biochemistry, genetics, and animal model studies and to discuss the future directions of OM studies in these areas. DATA SOURCES AND REVIEW METHODS: A structured search of the current literature (since June 2007). The authors searched PubMed for published literature in the areas of molecular biology, biochemistry, genetics, and animal model studies in OM. RESULTS: Over the past 4 years, significant progress has been made in the areas of molecular biology, biochemistry, genetics, and animal model studies in OM. These studies brought new insights into our understanding of the molecular and biochemical mechanisms underlying the molecular pathogenesis of OM and helped identify novel therapeutic targets for OM. CONCLUSIONS AND IMPLICATIONS FOR PRACTICE: Our understanding of the molecular pathogenesis of OM has been significantly advanced, particularly in the areas of inflammation, innate immunity, mucus overproduction, mucosal hyperplasia, middle ear and inner ear interaction, genetics, genome sequencing, and animal model studies. Although these studies are still in their experimental stages, they help identify new potential therapeutic targets. Future preclinical and clinical studies will help to translate these exciting experimental research findings into clinical applications.

Recurrent acute mastoiditis - a retrospective national study in Sweden.

CONCLUSIONS: Recurrences were seen in 5% of all patients with acute mastoiditis (AM). Mastoidectomy had been performed in the majority of the patients with recurrences at their first episode of AM. Compared with the group with a single episode of AM, the recurrent group exhibited more subperiosteal and ear canal abscesses, although they were not more severely ill. It appears from this study that previous mastoidectomy itself could predispose patients to recurrent AM (rAM), perhaps due to easier access to the mastoid cavity and/or due to a reduction in mucosal lining. OBJECTIVE: To retrospectively study the incidence and characteristics of rAM in Sweden. METHODS: Data from patients with rAM were reviewed and compared with data from patients with a single episode of AM during 1993-2007 in 33 ear, nose and throat departments in Sweden. RESULTS: Of 798 cases fulfilling the criteria for AM, 36 patients (5%) had experienced one or more recurrences, of which 4 patients (11%) had concurrent cholesteatoma. More than 50% of the patients had their first episode of AM before the age of 2 years. There was a highly significant difference between the two groups concerning the frequency of mastoidectomies and subperiosteal/retroauricular abscesses. However, other clinical characteristics, including severe complications, did not differ significantly. The majority of recurrences were treated conservatively with myringotomy and intravenous antibiotics, and also with aspiration/incision if a subperiosteal/retroauricular abscess was present.

Acute mastoiditis in children aged 0-16 years--a national study of 678 cases in Sweden comparing different age groups.

OBJECTIVE: To compare the characteristics of acute mastoiditis in children in different age groups in order to identify risk groups and risk factors for acute mastoiditis. METHODS: Records for all children aged 0-16 years treated for acute mastoiditis during 1993-2007 at 33 Ear, Nose and Throat departments in Sweden were reviewed retrospectively according to defined criteria for acute mastoiditis. RESULTS: A total of 678 cases fulfilled the inclusion criteria. Acute mastoiditis was most common in children younger than two years of age and this group was characterized by less prior history of other diseases and ear diseases, fewer visits to health care centers and less antibiotic treatment before admission, shorter duration of symptoms before admission, hospitalization for fewer days and lower frequency of complications and mastoidectomies. These children also showed a higher incidence of clinical findings, increased inflammatory markers such as fever and heightened counts of C-reactive protein and white blood cells compared with older children. They also tested positive for significantly more samples of Streptococcus pneumoniae while the older children more often exhibited growth of Streptococcus pyogenes or Pseudomonas aeruginosa or no microbial growth. CONCLUSIONS: The characteristics of pediatric acute mastoiditis differed significantly between age groups. Acute mastoiditis was most common in children younger than two years of age. They showed more rapid progress of symptoms and more distinct signs of acute mastoiditis. This is probably the reason why parents rapidly seek medical care for small children and hospital treatment thus starts earlier in the youngest children, which may in turn explain the excellent outcome. This study showed that younger children have neither more severe acute mastoiditis nor more complications than older ones. The differences between age groups suggest that there are distinctions in the pathophysiology behind the onset and course of acute mastoiditis in younger and older children.

Acute mastoiditis in children in Sweden 1993-2007--no increase after new guidelines.

OBJECTIVE: To study whether the incidence and characteristics of acute mastoiditis in children changed in Sweden following the introduction of new guidelines for diagnosis and treatment of acute otitis media advocating "watchful waiting" as an option in children 2-16 years of age with uncomplicated acute otitis media. METHODS: The records for all patients treated for mastoiditis during 1993-2007 at all Ear, Nose and Throat departments in Sweden were reviewed retrospectively according to defined criteria for acute mastoiditis. In this study the data from children aged 0-16 years were analyzed and compared 71/2 years before and 71/2 years after the introduction of the new guidelines in 2000. RESULTS: A total of 577 cases aged 0-16 years fulfilled the inclusion criteria during the whole study period. Cases involving cholesteatoma were excluded. The number of children affected by acute mastoiditis did not increase after the introduction of new guidelines. Acute mastoiditis was most common in children younger than two years of age. The proportion of acute mastoiditis increased after 2000 in the group aged 2-23 months although they were not affected concerning treatment by the new guidelines. No decrease was found in the frequency of prehospital antibiotic treatment among the children admitted with acute mastoiditis, and no increase was seen in the duration of ear symptoms before hospital admission, duration of hospital stay, or in the frequency of complications or mastoidectomies, after the introduction of the new guidelines in either group of children. CONCLUSIONS: The incidence of acute mastoiditis in children in Sweden did not increase following the introduction of new guidelines in 2000 for the diagnosis and treatment of acute otitis media. This is despite the fact that a significant decrease in antibiotic prescriptions for otitis media has been reported during the same time period. The characteristics of acute mastoiditis reflecting severity of illness did not change over time. Acute mastoiditis was most common and increased after 2000 only in children younger than two years of age in which antibiotics were still recommended in all cases of acute otitis media.