Acute otitis media in children--treatment options.CT Deshmukh
Department of Paediatrics, Seth G. S. Medical College, Mumbai. , USA
Keywords: Antibiotics, therapeutic use,Child, Drug Resistance, Microbial, Human, Nasal Decongestants, therapeutic use,Otitis Media, diagnosis,drug therapy,etiology,prevention &control,Risk Factors,
Acute otitis media (AOM) along with tonsillitis is one of the commonest diseases seen in children. It is often under-diagnosed and missed because of infrequent use of the otoscope by paediatricians. Recent reports of increasing bacterial resistance has led to rethinking of the approach to management of acute otitis media in children.
Seven out of ten children will have at least one episode of acute otitis media before the age of three years and a third of them are said to get recurrent attacks of AOM by the age of three years. The prevalence rates vary from country to country between 2.3% - 20%. The highest incidence is at two years of age. The treatment of ear infection accounts for over 40% of all antimicrobial medication use in children in the United States. There are no definite prevalence studies in India, but a study from Vellore in 1997 has shown that otitis media is cause of nearly 20% of all hearing loss.
AOM often accompanies respiratory infections, when nasal membranes and the Eustachian tube More Details become congested. Fluid secreted in the middle ear is trapped and creates an ideal environment for infection. A combination of important factors contributes to the pathogenesis of AOM. These include: Eusthachian tubal dysfunction, nasopharyngeal colonization with pathogenic bacteria and viruses, ascending infection along the Eustachian tube, immune status of the host, environmental factors and a genetic predisposition. The two most important factors in children are Eustachian tube dysfunction and the child’s susceptibility to recurrent upper respiratory tract infections. In the child the Eustachian tube is shorter (less distance for organism to travel), placed horizontal (inadequate drainage of middle ear) and has adenoids present at the opening, which can readily block the tube and serving as a reservoir of infection.
Bacteria are responsible for majority of cases. The three bacteria - Streptococcus pneumoniae (30-40%), Haemophilus influenzae i>(20%) and Moraxella More Details catarrhalis (7-20%) account for 80% of all case of AOM. Staphylococcus aureus are seen in some children, Streptococcus pyogenes y be seen in older children, Chlamydia pneumoniae may be seen in smaller children and gram-negative bacteria along with group B Streptococci may be seen in newborns.
Recent studies have shown viruses as the main causative factor in AOM. In one of the study upto 50% of isolates had grown viruses.
Although all children are susceptible to ear infection, those in the following groups are at a higher risk: children with history of allergy, whose siblings have history of recurrent ear infection, exposure to tobacco smoke, a family history of otitis media, frequent upper respiratory tract infection, bottle fed rather than breastfed and who spend time in day care centres. The most important risk factors are exposure to large number of older children. Other less common factors include - low birth weight babies, gastroesophageal reflux, bronchiolitis, cleft palate and immunodeficiency states.
The typical case begins with upper respiratory infection and depending on the age along with fever the following symptoms may appear alone or in combination:- irritability, disturbed sleep, earache, ear tugging, eye discharge, sensation of fullness in the ear, dizziness, nausea, vomiting and hearing loss. Ear discharge occurs after the tympanic membrane is perforated.
To diagnose the condition prior to perforation, examination with the otoscope is essential. Changes in colour, shape and flexibility of the membrane indicate the diagnosis of AOM.
Antibiotics usually Amoxicillin, Cotrimoxazole, first generation cephalosporins are prescribed for seven to ten days. Most children feel significantly better within 48-72 hours after starting antibiotics. The patient should be re-evaluated at two weeks for hearing problem and response. Analgesics and antipyretics like paracetamol can be given in the initial period. Antihistaminics have not been found to be useful in AOM and are not recommended.
Recent reports of increasing antibiotic resistance and reports of viral infection as a leading cause has resulted in different strategies adopted for treatment of AOM,,. It is extremely difficult to differentiate between bacterial and viral AOM clinically. Culture of middle ear fluid is rarely practicable. Nasal swabs are non-invasive and can provide useful microbiological information especially to rule out bacterial infection, but this is also not routinely done. Reports have shown that 20-60% of children with AOM show spontaneous resolution. It is not however possible to predict which children will show spontaneous resolution. Hence it will not be wrong if antibiotics are prescribed routinely to all children with AOM. This may increase the cost of therapy and more important may lead to increasing bacterial resistance.
Antibiotic treatment for AOM has been found to benefit one out of 20 children only. The benefit is mainly in reducing the pain in the initial stages of the disease. There is no evident benefit for deafness, recurrent attacks or complications. One recent meta-analysis has shown reduced deafness at 3 months post-antibiotic therapy.
It is now a routine practice in The Netherlands and Iceland to treat children with AOM using only nasal decongestant drops and analgesics. Antibiotics are reserved for only those who do not respond to the above treatment within three days. Such a strategy was associated with only two cases of mastoiditis and no cases of meningitis among nearly 5000 children. Both the cases of mastoiditis responded to oral antibacterial therapy. This strategy has resulted in lower prevalence of resistant bacterial strains both Iceland and The Netherlands.
This recommendation may be limited to AOM in developed countries. The complications of AOM in developing countries are likely to be more frequent and severe and it may not be advisable to follow such strategy until proper studies are conducted.
Withholding treatment is not appropriate for children with recurrent acute otitis media (RAOM) and each infection should be treated with antibiotics.
A high level of resistance is now being seen in the three principal pathogens of AOM (S. pneumoniae, H. influenzae, M. cartarrhalis). The incidence of H. influenzae is diminishing in western countries because of widespread vaccination, however resistance to the nontypable strains of H. influenzae to Amoxicillin is increasing. The prevalence of drug resistant pneumococci is increasing globally. Spain has one of the highest incidence upto 60% of strains being resistant to penicillin. India would fall into this group mainly because of very frequent use of antibiotics, nutritional problems and increase incidence of RAOM.
Recent multinational study covering USA and European countries have shown that the common susceptibility of the three main organisms to Amoxicillin - Clavulanic acid is between 90-95%, and to amoxicillin it is 60% in the USA. Beta lactamase was produced by 31% of H. influenzae and nearly 100% M. catarrhalis. The most important conclusion from most of these studies to discourage antibiotic prophylaxis for patients with recurrent AOM.
The penicillin resistance in pneumococci can be categorized as per the minimum inhibitory concentration (MIC). When MIC is <0.06 mg/ml the organism is always susceptible to oral cephalosporins, macrolides and cotrimaxozole along with penicillin. Intermediate resistance (MIC 0.12 to 1. 0 mg/ml) the resistance to oral cephalosporins and macrolides is likely to be more, however the organisms are sensitive to a higher dose of amoxicillin. When MIC is more than 2.0 mg/ml the organisms are likely to be resistant to all penicillins, cephalosporins and macrolides.
To optimize empirical regimens and initial therapy for S. pneumoniae infections the physicians must be aware about the prevalence and drug resistance among isolates in the community. In general the prevalence of drug resistance is more in the following groups of patients: Children less than one year, patients with RAOM, those who have received prior antibiotic treatment and children coming from child care centre. Such patients may be directly put on higher antibiotics.
Clinically one should consider the following aspects of drug resistance for empiric therapy:
Site of infection: e.g. pneumococcal infection in the middle ear or the central nervous system. In intermediate resistance a high dose of amoxicillin can be given to AOM cases, but in CNS cases third generation cephalosporins are first line of therapy. For infections where S. pneumoniae is a common agent, H. influenzae and/or Moraxella catarrhalis are also common, hence choice of antibiotic should be effective against these organisms also.
Level of penicillin resistance in Pneumonococci: Intermediate resistance in AOM will respond to higher amoxicillin doses but the same infection in CNS needs other treatment.
There are many antibiotics available for routine use in AOM. Amoxicillin is still considered the drug of choice because of the long track record of efficacy and safety. More importantly no antibiotic was found to be more effective than amoxicillin in clinical studies.
Use of non-beta lactum agents like Clindamycin or Rifamicin.
Use of single dose Ceftriaxone given intramuscularly. This was found to be as effective as 10 days treatment with Amoxicillin-Clavulanic acid.
Amoxicillin in higher doses 70-90 mg/kg/day in intermediate resistant cases.
The more commonly preferred agents amoxicillin-clavulanic acid, azithrocin or clarithromycin, cefuroxime and cefixime.
Five days short course treatment with amoxicillin or amoxicillin/clavalanic acid in uncomplicated cases.
Twice daily amoxicillin/clavalanic acid 70/10 mg/kg/day.
Both these options were as effective as conventional treatment but more economical with better compliance.
In cases of recurrent AOM adenoidectomy may be useful to remove the blockage and the source of infection.
The growing problem of resistance underscores the greater need for effective methods to prevent AOM. The various methods tried include:
Vaccination - There is considerable evidence to suggest that AOM can be prevented by Immunization with Hib (H.influenzae conjugated vaccine), pneumococcal vaccine and intranasal influenza vaccine. Pneumococcal vaccine cannot be given for children less than 2 years and the influenza vaccine is not widely used though found to be effective.
Passive immunization has potential for prevention and high dose RSV (Respiratory syntytial virus) enriched immunoglobulin has shown to reduce attacks of AOM.
Prolonged breast feeding protects infant from chronic otitis media and is known to reduce H. Influenzae & infections.
Washing hands frequently is the single most important thing you can do to prevent an infection including AOM.
If the child is bottle-fed then he should be fed in upright position.
Avoiding exposure to tobacco smoke (passive smoking).
In an allergic child sometimes elimination diet may be useful.
Xylitol reduces the growth of pneumococci and when administered in chewing gum it had some role in preventing AOM.This can be an interesting and acceptable alternative in children.
AOM along with tonsillitis are the two most common diseases seen in children. A careful examination of throat and ear is important in any child who presents with fever. AOM can be easily diagnosed by symptoms and examination. Amoxicillin is the drug of choice. When the patient does not respond in 2-3 days or other high risk factors are present other agents like Amoxycillin-clavulanic acid, althrocin /clarithrocin or cefuroxime/cefixime therapy may be given. The most important aspect is prevention in view of the growing threat of drug resistance.