Acute otitis media represents one of the most prevalent pediatric diagnoses encountered in ambulatory clinical practice, serving as a primary driver of outpatient antibiotic prescriptions worldwide. Characterized by rapid onset of mucosal inflammation within the normally sterile middle ear cleft accompanied by purulent effusion, this condition poses significant diagnostic, therapeutic, and public health considerations. Understanding its etiology, pathophysiology, diagnostic criteria, and management protocols is essential for mitigating risks of chronic sequelae and curbing antimicrobial resistance.
Acute Otitis Media
1. Concise Definition
Acute otitis media (AOM) is defined as an acute, symptomatic infection of the mucoperiosteal lining of the middle ear cleft, typified by the rapid onset of inflammatory signs and symptoms, the presence of middle ear effusion, and marked erythema or bulging of the tympanic membrane. It occurs predominantly in infants and young children following viral upper respiratory tract infections that compromise normal Eustachian tube function.
Clinically, the disorder is characterized by acute otalgia (or non-specific behavioral indicators such as ear tugging, irritability, and poor feeding in preverbal children), pyrexia, and otoscopic evidence of localized inflammation and fluid accumulation behind an intact or acutely perforated tympanic membrane. The pathophysiological hallmark is bacterial or viral proliferation within the entrapped middle ear space, creating suppurative exudate that exerts mechanical pressure against the tympanic membrane.
Distinguishing acute otitis media from otitis media with effusion (OME) is critical: while both involve middle ear effusion, AOM requires demonstrable evidence of acute inflammation and rapid symptom presentation, whereas OME features non-purulent fluid accumulation without systemic symptoms or acute inflammatory signs.
2. Etymology & Linguistic Origin
The term otitis media is derived from classical linguistic roots in ancient Greek and Latin. The prefix ot- originates from the Ancient Greek noun ous (genitive ōtos, ὠτός), signifying “ear.” The suffix -itis (borrowed from Greek -ῖτις) designates inflammation, a convention standardized in modern biomedical nomenclature to describe inflammatory tissue reactions.
The qualifying adjective media represents the feminine form of the Latin adjective medius, meaning “middle,” denoting the anatomical localization within the middle ear space (auris media), as distinct from otitis externa (affecting the external auditory canal) and otitis interna or labyrinthitis (affecting the inner ear neurosensory apparatus).
The descriptor acute is derived from the Latin verb acuere (“to sharpen”) and its participial adjective acutus (“sharp, pointed”), denoting a rapid, sudden onset and short clinical course, in contrast to subacute or chronic inflammatory presentations. The combined diagnostic designation gained standard scientific currency during the late nineteenth century as pathological anatomy and otology matured into distinct medical specialties.
3. Pronunciation & Grammatical Form
In standard medical English, the phrase is pronounced phonetically as /əˈkjuːt oʊˈtaɪtɪs ˈmiːdiə/. It functions grammatically as a compound noun phrase, classified as a non-count (uncountable) clinical entity, though plural forms referring to multiple disease episodes use “cases of acute otitis media” or occasionally “acute otitides mediae” in archaically formal pathological literature.
The standard abbreviation in scientific and clinical communication is AOM. Derived adjectival usage encompasses phrases such as “otitic complications” or “otitis-prone children.” When documented in clinical nosology systems, such as the International Classification of Diseases (ICD-10 code H66.0), it is categorized under suppurative and unspecified otitis media.
4. Detailed Conceptual Explanation
The pathogenesis of acute otitis media operates at the intersection of anatomical maturation, immunological competence, and microbiological exposure. The middle ear cleft constitutes an air-filled compartment bounded laterally by the tympanic membrane and medially by the promontory of the labyrinth. Under physiological circumstances, the mucosa of the middle ear secretes minimal mucus, which is continually propelled toward the nasopharynx by ciliated columnar respiratory epithelium via the Eustachian tube.
AOM typically initiates with an antecedent viral upper respiratory infection (URI) caused by pathogens such as respiratory syncytial virus (RSV), rhinovirus, adenovirus, or influenza. Viral replication causes widespread mucosal edema, loss of ciliary function, and hypersecretion within the nasopharynx and the Eustachian tube lining. Consequently, the physiological ventilatory and clearance functions of the Eustachian tube fail, establishing negative middle ear pressure followed by transudation of serous fluid into the tympanic cavity.
This persistent negative pressure, combined with forceful maneuvers such as crying, sniffing, or swallowing against a congested nasopharynx, aspirates nasopharyngeal secretions laden with bacterial flora into the stagnant middle ear space. The trapped microbial agents—most commonly Streptococcus pneumoniae, non-typeable Haemophilus influenzae, and Moraxella catarrhalis—proliferate rapidly within this warm, nutrient-rich transudate, triggering an intense immune cascade characterized by neutrophil influx, release of inflammatory cytokines (interleukin-1, interleukin-6, tumor necrosis factor-alpha), and conversion of serous transudate into purulent exudate.
The accumulation of purulent material exerts outward hydraulic pressure against the tympanic membrane, stretching free nerve endings from the glossopharyngeal and trigeminal nerves and inducing severe otalgia. If intra-tympanic pressure exceeds capillary perfusion pressure within the tympanic membrane, focal ischemic necrosis may occur, culminating in spontaneous perforation and otorrhea. Following perforation, pain often decreases acutely due to decompression of the middle ear cavity.
5. Historical Development
Historical descriptions of middle ear disease date back to antiquity. The Hippocratic corpus contains early references to pain originating within the ear accompanied by fever, recognizing that drainage of pus frequently coincided with the alleviation of pain, though middle ear infections were frequently conflated with brain abscesses and generalized head fevers.
In the mid-nineteenth century, Irish surgeon Sir William Wilde and English surgeon Joseph Toynbee systematically categorized pathological changes of the middle ear, pioneering early otoscopic visualization. In 1861, Austrian physician Adam Politzer published foundational treatises on otology, delineating Eustachian tube mechanics and introducing politzerization to restore middle ear aeration.
The pre-antibiotic era witnessed high rates of catastrophic intracranial complications, particularly acute coalescent mastoiditis, lateral sinus thrombosis, and meningitis, which carried substantial mortality rates. In 1873, German surgeon Hermann Schwartze described the simple mastoidectomy, establishing a life-saving surgical intervention to drain coalescent infection from the mastoid air cells.
The introduction of sulfonamides in the 1930s and penicillin in the 1940s transformed AOM from a potentially fatal or disfiguring surgical emergency into an ambulatory medical illness. However, the subsequent decades witnessed widespread, indiscriminate antibiotic prescribing, which fostered the emergence of beta-lactamase-producing organisms and penicillin-resistant Streptococcus pneumoniae by the late twentieth century. In response, modern professional societies, notably the American Academy of Pediatrics (AAP) and the American Academy of Otolaryngology–Head and Neck Surgery (AAO-HNS), standardized strict diagnostic criteria and introduced evidence-based watchful waiting protocols to optimize antimicrobial stewardship.
6. Theoretical Foundations
The conceptual framework underpinning acute otitis media spans several complementary biomedical theories, most notably the hydrodynamic theory of Eustachian tube mechanics, the microbial biofilm hypothesis, and the host-pathogen immunological paradigm.
The hydrodynamic model posits that Eustachian tube dysfunction (ETD) is the primary physical prerequisite for disease initiation. In young children, the Eustachian tube is anatomically shorter, wider, and positioned more horizontally (approximately 10 degrees relative to the horizontal plane, compared to 45 degrees in adults), while the tensor veli palatini muscle exhibits decreased mechanical stiffness. This immature architecture predisposes children to both functional obstruction and retrograde reflux of pathogenic nasopharyngeal secretions into the tympanic cavity.
The biofilm paradigm, advanced significantly in the 1990s and 2000s, posits that bacterial communities within the middle ear mucosa assemble into structured, extracellular polymeric matrices. Biofilms explain the paradox of recurrent AOM and persistent middle ear effusion, wherein bacterial cultures may yield negative or low viable counts despite active ongoing mucosal inflammation and persistent clinical signs. Bacteria within biofilms exhibit altered metabolic states that render them up to a thousand times more resistant to conventional systemic antibiotics and host phagocytosis.
Finally, the host-pathogen immunogenetic theory explains why certain individuals are classified as “otitis-prone” (experiencing three or more episodes in six months, or four or more within twelve months). Variations in mucosal innate immunity, including polymorphisms in human leukocyte antigens (HLA), mannose-binding lectin, and Toll-like receptors (notably TLR4), impair early bacterial clearance, predisposing specific pediatric populations to recurrent suppurative episodes following banal viral infections.
7. Key Components, Types & Dimensions
The clinical spectrum of middle ear inflammatory conditions can be classified across several discrete dimensions based on temporal evolution, microbiological traits, and structural manifestations:
- Isolated Acute Otitis Media (AOM): A discrete, single episode characterized by rapid symptom onset, tympanic membrane bulging, erythema, and middle ear purulence that resolves fully following appropriate antimicrobial therapy or natural host clearance.
- Recurrent Acute Otitis Media (RAOM): Defined formally by clinical guidelines as three or more distinct episodes of documented AOM within a six-month period, or four or more episodes within twelve months (with at least one episode occurring within the preceding six months), requiring complete resolution of symptoms between episodes.
- Acute Bullous Myringitis: A variant of AOM in which serosanguinous or purulent blebs (vesicles) form directly on the outer epithelial layer of the tympanic membrane; historically attributed exclusively to Mycoplasma pneumoniae, modern virological and bacteriological studies demonstrate that standard AOM pathogens (such as S. pneumoniae) are the primary culprits.
- AOM with Spontaneous Perforation: Characterized by the acute drainage of purulent fluid (otorrhea) through a freshly disrupted tympanic membrane, typically resulting in rapid diminution of otalgia due to spontaneous decompression.
- Otitis Media with Effusion (OME): Defined by the persistence of fluid in the middle ear cleft without acute clinical symptoms or signs of active infection; commonly precedes AOM or persists for weeks to months following its clinical resolution (often referred to as “glue ear”).
- Chronic Suppurative Otitis Media (CSOM): A persistent, non-healing perforation of the tympanic membrane associated with active, recurrent, or chronic purulent otorrhea lasting longer than six to twelve weeks, characterized by distinct microbial pathogens (such as Pseudomonas aeruginosa and Staphylococcus aureus).
8. Examples & Illustrative Cases
To contextualize these clinical classifications, the following vignettes illustrate common presentations encountered in pediatric and adult clinical practice:
Case Illustration 1: Uncomplicated Pediatric AOM
A 14-month-old male is brought to a pediatric clinic by his parents due to extreme irritability, sleeplessness, and a fever of 39.0°C (102.2°F). The infant had symptoms of a viral upper respiratory infection (rhinorrhea, mild cough) for the preceding four days. During physical examination, pneumatic otoscopy reveals a markedly bulging, opaque, erythematous right tympanic membrane with complete loss of normal bony landmarks (malleus handle) and absent mobility upon positive pressure insufflation. The left tympanic membrane is translucent and mobile. In accordance with current clinical practice guidelines, because of the patient’s age and high fever, oral high-dose amoxicillin is initiated, and antipyretics/analgesics are administered for pain control. Symptoms resolve within 48 hours.
Case Illustration 2: Perforated AOM in an Older Child
A 7-year-old female presents with a sudden cessation of severe right ear pain accompanied by the acute appearance of yellowish discharge in the external auditory canal. Prior to the onset of discharge, the child experienced 12 hours of agonizing otalgia and mild pyrexia. Otoscopic inspection after gentle suctioning of purulent discharge reveals a small, pulsatile pinpoint perforation in the inferior quadrant of the pars tensa with active discharge. The surrounding membrane remains hyperemic. The patient is treated with topical fluoroquinolone otic drops (which do not exhibit ototoxicity in the presence of a perforated tympanic membrane) along with systemic analgesia, leading to complete structural closure of the membrane within three weeks.
9. Measurement & Assessment
Accurate clinical diagnosis of acute otitis media requires strict adherence to standardized diagnostic criteria to avoid both underdiagnosis and overtreatment with antimicrobials. The gold standard for bedside clinical diagnosis is pneumatic otoscopy, which assesses both the structural visualization and the dynamic mechanical compliance of the tympanic membrane.
Diagnostic guidelines established by the American Academy of Pediatrics require three core elements for a definitive diagnosis of AOM:
- Moderate to Severe Bulging of the Tympanic Membrane: This is the single most reliable otoscopic sign of acute middle ear purulence. Alternatively, mild bulging accompanied by recent-onset otalgia (less than 48 hours) or intense erythema satisfies criteria.
- Evidence of Middle Ear Effusion (MEE): Confirmed via pneumatic otoscopy demonstrating decreased or absent membrane mobility, or visualization of an air-fluid level, opacification, or spontaneous purulent otorrhea not caused by otitis externa.
- Signs and Symptoms of Acute Middle Ear Inflammation: Demonstrated by distinct tympanic membrane erythema alongside acute otalgia, fever, or noticeable systemic irritability.
Supplementary objective diagnostic modalities include tympanometry and acoustic reflectometry. Tympanometry utilizes an acoustic probe to measure electroacoustic impedance across varying external canal air pressures; a flat, non-compliant tracing (Type B tympanogram) confirms the presence of effusion, though it cannot distinguish between sterile fluid (OME) and suppurative exudate (AOM).
Tympanocentesis (aspiration of middle ear fluid using a small-gauge needle passed through the inferior tympanic membrane) represents the microbiologic gold standard. While rarely indicated in routine primary care, tympanocentesis is utilized in neonates, immunocompromised hosts, patients failing multiple courses of second-line antibiotics, or cases exhibiting emergent intracranial complications to perform definitive microbial culture and antimicrobial susceptibility testing.
10. Applications & Practical Significance
The clinical and operational management of acute otitis media has broad implications for healthcare systems, clinical pharmacology, and public health policy. Therapeutic pathways balance immediate symptom relief against the imperative for antimicrobial stewardship.
First-line therapy for uncomplicated AOM revolves around robust systemic analgesia. Acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen represent the mainstay of symptomatic care, as systemic antibiotics exert minimal impact on pain within the initial 24 hours of administration.
For definitive management, the AAP guidelines outline criteria for initial antimicrobial therapy versus an “observation option” (watchful waiting for 48 to 72 hours) in select cohorts:
- Children aged 6 months to 23 months with unilateral, non-severe AOM (mild otalgia, temperature below 39°C), and children aged 2 years and older with mild symptoms, may be offered close observation with parental agreement, reserving antibiotics for symptom persistence or deterioration.
- Children under 6 months of age, children presenting with severe otalgia or fever ≥39°C, and children under 2 years of age with bilateral AOM should receive immediate antimicrobial therapy.
When antibiotics are indicated, high-dose amoxicillin (80–90 mg/kg/day divided into two doses) serves as the preferred first-line pharmacological agent. This dosage overcomes intermediate penicillin resistance among strains of Streptococcus pneumoniae by achieving therapeutic concentrations within middle ear fluid. If the patient has received amoxicillin within the prior 30 days, presents with concurrent purulent conjunctivitis (otitis-conjunctivitis syndrome, often caused by non-typeable H. influenzae), or fails initial amoxicillin therapy after 48–72 hours, high-dose amoxicillin-clavulanate (with a 14:1 ratio of amoxicillin to clavulanate) is indicated to cover beta-lactamase-producing organisms.
For children with recurrent acute otitis media or persistent middle ear effusions contributing to conductive hearing loss, surgical placement of bilateral tympanostomy tubes (grommets) offers significant clinical benefit. Tympanostomy tubes equalize middle ear pressure, provide drainage pathways for recurrent exudates, and allow subsequent episodes of otorrhea to be managed with topical otic fluoroquinolone suspensions rather than repeated rounds of broad-spectrum systemic antimicrobials.
11. Research & Empirical Evidence
The microbiological landscape of acute otitis media has undergone profound changes following the introduction of routine pediatric conjugate vaccines. Seminal longitudinal studies conducted by investigators such as Pichichero, Casey, and Klein have mapped shifts in pathogen distribution over several decades.
Prior to the introduction of the 7-valent pneumococcal conjugate vaccine (PCV7) in 2000, Streptococcus pneumoniae was responsible for approximately 40% to 50% of all bacterial AOM cases, followed by non-typeable Haemophilus influenzae (30% to 40%) and Moraxella catarrhalis (10% to 15%). Following widespread pediatric immunization with PCV7 and the subsequent 13-valent conjugate vaccine (PCV13), the overall incidence of pneumococcal AOM declined significantly, driven by a reduction in vaccine-serotype carriage.
Concurrently, microbiological surveillance documented an absolute or relative surge in non-typeable Haemophilus influenzae isolates as the predominant cause of acute middle ear infections in vaccinated cohorts, alongside serotype replacement by non-vaccine strains of S. pneumoniae (such as serotype 35B and 19A prior to expanded valencies). Because up to 40% to 50% of H. influenzae isolates and nearly 100% of M. catarrhalis isolates produce beta-lactamase enzymes, this epidemiological shift continues to influence clinical recommendations regarding amoxicillin-clavulanate utilization in treatment failures.
Large-scale randomized controlled trials, such as landmark investigations published by Tähtinen et al. (2011) and Hoberman et al. (2011) in the New England Journal of Medicine, evaluated the efficacy of antimicrobial treatment versus placebo in rigorously diagnosed AOM. Both studies confirmed that stringent diagnostic criteria (requiring marked bulging of the tympanic membrane) identified a subgroup of young children who derived clear clinical benefits from antimicrobial treatment—demonstrating shorter duration of systemic symptoms, faster resolution of tympanic membrane inflammation, and decreased rates of persistent treatment failure compared to placebo—reinforcing the importance of precise otoscopic assessment over non-specific symptomatic diagnosis.
12. Cultural & Cross-Cultural Considerations
The global epidemiological footprint of acute otitis media exhibits substantial cross-cultural and socioeconomic disparities. According to World Health Organization (WHO) estimates, acute and chronic otitis media affect hundreds of millions of children globally, resulting in significant global burdens of preventable childhood hearing impairment.
Certain indigenous populations, including Australian Aboriginal children, Native American and Inuit populations, and Māori communities, exhibit disproportionately elevated rates of recurrent AOM, early infant onset, chronic perforation, and progression to chronic suppurative otitis media. Pathophysiological contributors include anatomical variations in craniofacial and Eustachian tube architecture, higher rates of dense nasopharyngeal bacterial colonization occurring within weeks of birth, and widespread environmental stressors.
Socioeconomic determinants of health substantially influence disease susceptibility and outcomes across both high- and low-income countries. Major modifiable risk factors identified across epidemiological studies include:
- Household Tobacco Smoke Exposure: Passive inhalation of tobacco smoke paralyzes respiratory ciliary structures within the Eustachian tube and middle ear mucosa, impairs local macrophage activity, and doubles the odds of childhood middle ear disease.
- Infant Feeding Modalities: Exclusive breastfeeding for the first six months of life confers significant protection against AOM, mediated by passive transfer of maternal secretory IgA antibodies and the physiological biomechanics of suckling, which prevents liquid reflux into the Eustachian tube.
- Childcare Attendance: Enrollment in group daycare facilities dramatically increases viral transmission rates among young infants, leading to frequent upper respiratory infections that trigger Eustachian tube obstruction and subsequent middle ear disease.
- Overcrowded Living Conditions: High domestic density facilitates early and dense colonization with multi-drug-resistant respiratory pathogens.
13. Criticisms, Debates & Limitations
A central controversy surrounding acute otitis media concerns diagnostic accuracy in routine clinical practice. Studies consistently demonstrate that non-otolaryngologist clinicians frequently misdiagnose otitis media with effusion (OME) or simple viral myringitis as acute otitis media, leading to avoidable antibiotic prescriptions. Inaccurate examinations are often compounded by uncooperative pediatric patients, obscuring cerumen impactions in the external auditory canal, and inadequate pneumatic otoscopy equipment.
The debate between universal antibiotic therapy and the watchful waiting strategy represents another long-standing point of clinical discussion. Advocates of routine initial observation point out that up to 70% to 80% of uncomplicated AOM episodes resolve spontaneously without antibiotics due to endogenous host immune clearance. Overprescribing antibiotics contributes directly to the emergence of resistant microbial strains, alters the infant gut microbiome, and increases risks of allergic hypersensitivity reactions.
Conversely, opponents of widespread watchful waiting emphasize the practical challenges of reliable outpatient reassessment within 48 to 72 hours, particularly in vulnerable populations or healthcare systems where direct follow-up cannot be guaranteed. Furthermore, withholding antibiotics carries small but serious risks of disease progression to suppurative complications, including acute mastoiditis, facial nerve paralysis, subperiosteal abscess, and intracranial infections such as meningitis or sigmoid sinus thrombosis.
Finally, there is ongoing clinical debate regarding optimal antibiotic treatment duration. While historical clinical regimens favored a standard 10-day course, modern comparative trials suggest that shortened 5-day regimens may be adequate for older children (aged 2 years and above) with mild, uncomplicated disease, though shorter courses in children under 2 years of age have been associated with higher rates of clinical failure and relapse.
14. Related Terms & Distinctions
To avoid diagnostic ambiguity, acute otitis media must be systematically differentiated from related otologic conditions:
- Otitis Media with Effusion (OME): Defined as the presence of non-purulent fluid in the middle ear cleft without signs or symptoms of acute ear infection (such as otalgia, fever, or tympanic erythema/bulging). Unlike AOM, OME does not warrant systemic antibiotic therapy and typically resolves spontaneously within three months.
- Otitis Externa (Swimmer’s Ear): Diffuse inflammation and infection of the external auditory canal skin, characteristically presenting with intense pain upon manipulation of the tragus or pinna, canal edema, and purulent discharge. The tympanic membrane may appear erythematous, but pneumatic mobility and middle ear status remain normal unless the membrane is obscured.
- Chronic Suppurative Otitis Media (CSOM): Characterized by chronic (persisting for weeks to months), painless, purulent drainage through a permanent tympanic membrane perforation. The microbiological spectrum differs fundamentally from AOM, featuring opportunistic Gram-negative organisms like Pseudomonas aeruginosa and Proteus mirabilis, alongside Staphylococcus aureus.
- Myringitis: Isolated inflammatory involvement of the external epithelial layer of the tympanic membrane, presenting with localized erythema or vesiculation, without underlying middle ear effusion or pneumatic dysfunction.
- Referred Otalgia: Ear pain originating from non-otologic structures sharing cranial nerve pathways (cranial nerves V, VII, IX, and X, and cervical nerves C2 and C3). Common sources include dental disease, temporomandibular joint (TMJ) dysfunction, tonsillitis, and pharyngeal or laryngeal malignancies, all of which exhibit entirely normal otoscopic examinations.
15. Summary / Key Takeaways
Acute otitis media remains a quintessential pediatric condition characterized by acute inflammation and purulent effusion within the middle ear cleft. Typically initiated by viral upper respiratory tract infections that induce Eustachian tube dysfunction, negative pressure, and bacterial contamination, its predominant causative organisms include Streptococcus pneumoniae, non-typeable Haemophilus influenzae, and Moraxella catarrhalis.
Definitive diagnosis requires pneumatic otoscopy demonstrating moderate-to-severe tympanic membrane bulging or new-onset purulent otorrhea in the presence of acute clinical symptoms. Management hinges upon adequate pain control with oral analgesics, selective implementation of watchful waiting in appropriate patient cohorts, and prompt administration of high-dose amoxicillin or amoxicillin-clavulanate when antimicrobial treatment is indicated.
Routine immunization with pneumococcal conjugate and influenza vaccines, avoidance of tobacco smoke exposure, and promotion of breastfeeding represent crucial preventive strategies. Continued diagnostic precision and adherence to established clinical guidelines remain fundamental to reducing inappropriate antibiotic usage, preventing dangerous suppurative sequelae, and ensuring optimal developmental and otologic outcomes in pediatric populations worldwide.
References
- American Academy of Family Physicians, American Academy of Otolaryngology–Head and Neck Surgery, & American Academy of Pediatrics. (2013). Clinical practice guideline: Diagnosis and management of acute otitis media. Pediatrics, 131(3), e964–e999. https://doi.org/10.1542/peds.2012-3488
- Hoberman, A., Paradise, J. L., Rockette, H. E., Shaikh, N., Wald, E. R., Kearney, D. H., Colborn, D. K., Kurs-Lasky, M., Bhatnagar, S., Haralam, M. A., Zoffel, L. M., Jenkins, C., Pope, M. A., Balentine, T. L., & Martin, J. M. (2011). Treatment of acute otitis media in children under 2 years of age. New England Journal of Medicine, 364(2), 105–115. https://doi.org/10.1056/NEJMoa0912254
- Klein, J. O. (2000). The burden of otitis media. Vaccine, 19(Suppl 1), S2–S8. https://doi.org/10.1016/S0264-410X(00)00271-1
- Pichichero, M. E. (2013). Otitis media. Pediatric Clinics of North America, 60(2), 391–407. https://doi.org/10.1016/j.pcl.2012.12.007
- Tähtinen, P. A., Laine, M. K., Huovinen, P., Jalava, J., Ruuskanen, O., & Ruohola, A. (2011). A placebo-controlled trial of antimicrobial treatment for acute otitis media. New England Journal of Medicine, 364(2), 116–126. https://doi.org/10.1056/NEJMoa1007174