Pediatric Annals

Pitfalls in Diagnosing Acute Otitis Media

Raymond C Baker, MD

Abstract

Acute (suppurative) otitis media (AOM) is the most common illness diagnosed by the pediatrician in infants and children seen for an illness visit. As many as one third of all illness visits and one fifth of all office visits are related to AOM - more than 30 million visits nationwide annually.1 The incidence of otitis is greatest in young children, with two thirds of cases occurring in the first 3 years of life. Age-specific incidence has been reported as 14% in the first year, 18% in the second, 12% in the third, and 10% to 11% in the next 3 years with a marked decline in incidence after the age of 6 years.2

The dollar cost of the care of children with otitis media represents a proportionally large section of the outpatient dollar. A routine illness visit with a brief follow-up visit plus antibiotics costs an average of $60 in the Cincinnati area for patients with uncomplicated AOM. If one considers the costs of complicated otitis media (eg, recurrent AOM, chronic otitis media with effusion [OME], and chronic suppurative otitis media), including repeat office visits, antimicrobial prophylaxis, and subsequent otolaryngologic procedures, otitis media becomes a major factor in the pediatrie medical dollar with an estimated annual expenditure of $2 billion in the United States.3 Adding the costs in time and family stress secondary to illness in young children, it becomes apparent that otitis media is a major health problem in young children.

Unfortunately, the age of greatest prevalence of otitis media corresponds with the age at which the history and clinical examination are most difficult because of the young child's inability to describe symptoms, the lack of the patient's cooperation, and the size of the ear canal. It is the nature of young children to distrust the clinical examination, especially when it involves the introduction of an instrument into the child's ear. For these reasons, the diagnosis of otitis may be difficult and prone to error, even with an experienced practitioner. This article describes some aspects of the history and physical examination that may lead to an inaccurate diagnosis of AOM in the infant and young child.

HISTORY

Otalgia

While otalgia strongly suggests AOM in the older child, a history of ear pain in the preverbal infant is often vague and difficult to elicit. Although the symptom of "pulling the ears" is well known to the practitioner this activity may be unrelated to AOM and may represent a habit, play activity, or a reaction to an irritation of the external auditory rather than middle ear disease. In the older child, the symptom of ear pain, while most commonly related to AOM, may indicate developing external otitis, trauma (including barotrauma), or the presence of a foreign body. Other less common causes of ear pain in the infant and child are indicated in Table 1.4

Table

In the child who presents with a fever, residual middle ear fluid from a recent episode of AOM can lead to confusion if it is the only abnormal physical finding. Because the differences in appearance between residual noninfected serous fluid and suppurative fluid may be subtle, especially when they are appreciated only indirectly through changes in the appearance of the TM, practitioners often treat children with antibiotics empirically in this circumstance recognizing the possibility that the MEC fluid and fever may not be related.

OTHER VARIABLES

The presence of tympanostomy tubes may alter the findings of AOM due to the presence of the foreign body itself or to alterations in the TM secondary to chronic otitis media, which prompted the placement of tympanostomy tubes. Common findings…

Acute (suppurative) otitis media (AOM) is the most common illness diagnosed by the pediatrician in infants and children seen for an illness visit. As many as one third of all illness visits and one fifth of all office visits are related to AOM - more than 30 million visits nationwide annually.1 The incidence of otitis is greatest in young children, with two thirds of cases occurring in the first 3 years of life. Age-specific incidence has been reported as 14% in the first year, 18% in the second, 12% in the third, and 10% to 11% in the next 3 years with a marked decline in incidence after the age of 6 years.2

The dollar cost of the care of children with otitis media represents a proportionally large section of the outpatient dollar. A routine illness visit with a brief follow-up visit plus antibiotics costs an average of $60 in the Cincinnati area for patients with uncomplicated AOM. If one considers the costs of complicated otitis media (eg, recurrent AOM, chronic otitis media with effusion [OME], and chronic suppurative otitis media), including repeat office visits, antimicrobial prophylaxis, and subsequent otolaryngologic procedures, otitis media becomes a major factor in the pediatrie medical dollar with an estimated annual expenditure of $2 billion in the United States.3 Adding the costs in time and family stress secondary to illness in young children, it becomes apparent that otitis media is a major health problem in young children.

Unfortunately, the age of greatest prevalence of otitis media corresponds with the age at which the history and clinical examination are most difficult because of the young child's inability to describe symptoms, the lack of the patient's cooperation, and the size of the ear canal. It is the nature of young children to distrust the clinical examination, especially when it involves the introduction of an instrument into the child's ear. For these reasons, the diagnosis of otitis may be difficult and prone to error, even with an experienced practitioner. This article describes some aspects of the history and physical examination that may lead to an inaccurate diagnosis of AOM in the infant and young child.

HISTORY

Otalgia

While otalgia strongly suggests AOM in the older child, a history of ear pain in the preverbal infant is often vague and difficult to elicit. Although the symptom of "pulling the ears" is well known to the practitioner this activity may be unrelated to AOM and may represent a habit, play activity, or a reaction to an irritation of the external auditory rather than middle ear disease. In the older child, the symptom of ear pain, while most commonly related to AOM, may indicate developing external otitis, trauma (including barotrauma), or the presence of a foreign body. Other less common causes of ear pain in the infant and child are indicated in Table 1.4

Table

TABLE 1Causes of Otalgia in Children*

TABLE 1

Causes of Otalgia in Children*

Otorrhea

Mucopurulent otorrhea may occur in AOM following rupture of the tympanic membrane (TM) or through patent tympanostomy tubes and strongly suggests AOM. However, other causes of otorrhea occur in infants and children, the most common pathologic etiology being external otitis. A common nonpathologic cause of otorrhea is physiologic otorrhea, which represents normal cerumen liquefied by tears or water in the external auditory canal (EAC) or by the warm environment created by fever. Other causes of pathologic otorrhea are indicated in Table 2.4

Fever

Although fever as a symptom often has been linked with AOM, the pediatrie literature conflicts on this association. Schwartz et al5 prospectively evaluated the occurrence of fever in patients with AOM seen in a private office setting and reported only 23% of patients with a temperature above 38.20C. They speculated that in patients from lower socioeconomic groups, fever might be the symptom that prompted seeking medical care, which would account for the higher incidence of fever (67%) previously reported.6

Table

TABLE 2Causes of Otorrhea in Children*

TABLE 2

Causes of Otorrhea in Children*

Upper Respiratory Tract Symptoms

Rhinorrhea, congestion, and cough are commonly seen as one would expect given the role of viral respiratory tract infections in the pathogenesis of AOM. Howie and Schwartz7 reported that 41% of patients with AOM have associated rhinorrhea, usually purulent, and that 17% have cough. The association of conjunctivitis likewise has been noted, usually with nontypable Hoemophilus influenzas as the enologie agent, but this syndrome occurs in only a small number.8

Nonspecific Symptoms

Nonspecific symptoms, such as irritability, lethargy, poor appetite, vomiting, and diarrhea, also may occur with AOM, but probably represent reactions to pain, fever, or mediators of the inflammatory reaction induced by the organism.

Figures 1-3. Methods of restraining an uncooperative child for examination. Figure 1 (left) demonstrates restraint by an assistant for otoscopie examination, Figure 2 (middle) demonstrates the restraint of a child's arms and body by the examiner preparatory to the otoscopie examination, and Figure 3 (right) demonstrates the otoscopie examination with the child's arms, body, and head restrained by the examiner.

Figures 1-3. Methods of restraining an uncooperative child for examination. Figure 1 (left) demonstrates restraint by an assistant for otoscopie examination, Figure 2 (middle) demonstrates the restraint of a child's arms and body by the examiner preparatory to the otoscopie examination, and Figure 3 (right) demonstrates the otoscopie examination with the child's arms, body, and head restrained by the examiner.

PHYSICAL EXAMINATION

The physical examination of the infant and child with suspected AOM is often difficult and is the greatest source of error in diagnosing AOM. One of the primary difficulties in the examination is related to the infant's reaction to the examiner. A negative reaction may be related to a past experience with an ear examination in which the child experienced discomfort, perhaps from cerumen removal or pressure from the otoscope speculum. More commonly in the young infant, it is a global reaction to a stranger caused by either the child's stage of cognitive development or a dislike for being restrained for the examination.

Several factors influence the examination of the child's ear to permit optimal visualization of the TM. The first is adequate immobilization of the child's head to optimize the examination and minimize discomfort to the infant in the process. Because this part of the examination may be unpleasant for the infant, it is usually best to leave the ear examination to the end of the overall physical examination and then do it as quickly as possible. Several methods of restraining the child can be used. If an assistant is available or the child's mother can assist, the infant can usually be restrained in the holder's lap with the head held still against the holder's chest by the hand while the legs are immobilized if necessary between the holder's overlapped legs (Figure 1). When no assistant is available, the author's preference is to examine the child on the examining table in the supine position with the examiner's arms restraining the child's arms (Figure 2). The examiner's hands are then free to restrain the head, manipulate the auricle, and hold the otoscope (Figure 3).

Cerumen in the EAC can prevent an accurate assessment in three ways. First, the busy examiner may be tempted to use a smaller speculum and look through an opening in the cerumen, which decreases the view of the TM and makes insufflation inaccurate. Second, bleeding from attempts at cleaning the canal may not only occlude the canal, but also decrease the cooperation of the child (and parent). And third, the cleaning method itself may cause redness of the TM, although mobility should not be affected.

Several methods of cleaning are effective. A cerumen spoon works well, but requires considerable skill (Figure 4)· Even the most experienced examiner occasionally induces bleeding of the canal. A stream of lukewarm water either from a large syringe or an oral water jet (eg, a Waterpik, Teledine Waterpik, Collins, Colorado) is effective, but may be frightening to the child. The instillation of 3% hydrogen peroxide drops within the EAC before the water jet is used often loosens the cerumen and makes the water jet more effective. The author's preference is to use an aluminum wire, cottontipped applicator (eg, Calgiswab, Spectrum Laboratories, Ine, Houston, Texas) for cleaning EACs. These can be used to best effect by twirling variable amounts of extra cotton onto its end to cleanse the EAC or by bending the wire over on itself and twisting to make a disposable cerumen spoon (Figure 4). Because of the smooth round contour of the wire, there is less likelihood of causing bleeding of the EAC with this hand-made cerumen spoon. Cerumen softeners are most effective if instilled within the EAC prior to the visit. Because some of these may cause irritation to the EAC, the parent should be given specific instructions for their use.

Figure 4. From top to bottom: hand-made cerumen spoon; aluminum wire, cotton-tipped applicators with extra cotton at tip; plastic, disposable cerumen spoons; and metal cerumen spoons.

Figure 4. From top to bottom: hand-made cerumen spoon; aluminum wire, cotton-tipped applicators with extra cotton at tip; plastic, disposable cerumen spoons; and metal cerumen spoons.

The pneumatic otoscope itself can contribute to inaccurate assessment. A properly functioning otoscope must have 1) an adequate light source, 2) an airtight seal at the point of contact between the magnifying lens and the otoscope head, 3 ) an airtight seal at the point of contact between the speculum and the otoscope head, and 4) an airtight insufflation bulb and tubing to provide positive and negative pressure to the EAC. Leakage at any of these sites and at the contact points of the tip of the speculum and the EAC can result in apparent decreased mobility of the TM with insufflation (pneumatic otoscopy). The otoscope should be checked for its integrity at each of these potential air-leakage sites before the examination by occluding the speculum tip with a fingertip and compressing the bulb. If the system is intact, there should be resistance to compression of the bulb.

TYMPANIC MEMBRANE

The tympanic membrane, even when fully viewed, may offer findings that may lead to inaccuracies in the diagnosis. There may be a considerable range of normal findings depending on the age of the child, previous episodes of AOM, and previous surgical procedures. Table 3 indicates the elements of a normal TM and the changes seen in AOM and OME.

Mobility

The application of positive and negative pressure to the sealed EAC with the insufflation bulb to demonstrate mobility of the TM is crucial to the diagnosis of AOM because it is the presence of pus in the middle ear cavity (MEC) with resulting decreased mobility of the TM that ultimately defines otitis media.4 In order to effect movement of the TM, an airtight seal must be maintained in the space contained by the tip of the otoscope's speculum within the EAC. To prevent air leakage at the point of contact between the tip of the speculum and the EAC, using the largest speculum that will fit the EAC and slipping a piece of rubber tubing over the tip of the speculum will provide a better seal and less chance of causing pain to the external canal during the examination. Alternatively, there are speculae now available with rubber tips to accomplish the same purpose.

Table

TABLE 3Physical Examination of the Tympanic Membrane

TABLE 3

Physical Examination of the Tympanic Membrane

Integrity

Perforation of the tympanic membrane invariably indicates the presence of middle ear disease. Perforation with the drainage of pus may be seen in acute disease; perforation without fluid drainage may indicate a more chronic process such as an unhealed perforation of long standing. Occasionally, an air bubble within the fluid behind the TM may mimic a perforation. Less commonly, retraction pockets, cholesteatomas, or a bulla on the TM may give the appearance of a perforation. In any event, careful examination with pneumatic otoscopy and perhaps tympanometry should clarify the findings.

Contour

The contour of the TM may suggest positive pressure and purulent fluid behind the TM when there is an outward bulging associated with a loss of landmarks (ie, AOM). Conversely, inward retraction of the TM toward the MEC is seen with negative middle ear pressure and depicts the middle ear ossicles in bas relief Both of these findings usually require confirmation with pneumatic otoscopy because of the large variation in the appearance of the normal TM.

Landmarks

Several landmarks are usually visible in the normal TM, including the pars flaccida and tensa of the TM, the manubrium of the malleus, and an anteroinferior light reflex. If the TM is sufficiently transparent, the incudostapedial junction and chorda tympani can be seen superiorly and the round window niche inferiorly and posteriorly.4 The presence of a light reflex depends on the luster of the TM (which is commonly altered in children with previous episodes of otitis media) and the angle of the light source; therefore, its absence is not a reliable sign of otitis media. Visibility of the other landmarks depend on the transparency of the TM, which also may be altered by previous episodes of otitis media, making their absence likewise unreliable as indicators of AOM without other findings.

Color, Transparency, and Luster

The color of the TM is variable in health and disease. Usually varying from gray to pink, the TM may appear red when intravascular pressure is raised from crying. The primary circumstance in which erythema alone may be a pathologic finding is in early AOM when myringitis is present prior to the development of pus in the MEC.2 This is most easily appreciated when it occurs unilaterally. Transparency and luster of the TM may be affected early in the course of AOM by a similar mechanism. However, these are commonly altered in infants with previous episodes of AOM and in very young infants.

MIDDLE EAR CAVITY

The most reliable indicator of AOM is the actual visualization of pus in the MEC through a transparent TM. However, the MEC frequently may not be visible through a TM rendered opaque by myringitis or chronic changes from previous episodes of AOM. Loss of the normal translucency alone may give the iliusion of pus in the MEC and requires pneumatic otoscopy to confirm.

Table

TABLE 4Factors Altering the Appearance of the Tympanic Membrane Not Associated With Acute Otitis Media

TABLE 4

Factors Altering the Appearance of the Tympanic Membrane Not Associated With Acute Otitis Media

In the child who presents with a fever, residual middle ear fluid from a recent episode of AOM can lead to confusion if it is the only abnormal physical finding. Because the differences in appearance between residual noninfected serous fluid and suppurative fluid may be subtle, especially when they are appreciated only indirectly through changes in the appearance of the TM, practitioners often treat children with antibiotics empirically in this circumstance recognizing the possibility that the MEC fluid and fever may not be related.

OTHER VARIABLES

The presence of tympanostomy tubes may alter the findings of AOM due to the presence of the foreign body itself or to alterations in the TM secondary to chronic otitis media, which prompted the placement of tympanostomy tubes. Common findings in patients with tympanostomy tubes, in the absence of acute infection, include decreased mobility, altered or absent landmarks, opacity, and dullness. Acute otitis media may produce symptoms of fever and pain associated with physical findings of erythema and discharge from the tympanostomy tube if the tube is patent. If the tube is not patent, erythema, bulging of the TM, and immobility are consistent with the diagnosis of AOM.

The appearance and contour of the TM differs between very young iniants and older infants and children. A review of pneumatic otoscopie findings in healthy full-term infants by Cavanaugh9 revealed decreased mobility of the TM up to 10 weeks of age, and dullnesss, decreased light reflex, and decreased translucence for up to 4 months of age (90% at 3 days, 26% at 4 months). In addition, the position of the TM relative to the EAC is different in young infants. The TM in young infants is situated at a more acute angle to the examiner's line of vision, which makes it more difficult to visualize and more difficult to detect movement with insufflation.

SUMMARY

The diagnosis of AOM in the infant and child requires an accurate history with special reference to fever, pain, and respiratory symptoms and a careful examination with particular attention to the appearance and movement of the TM. The practitioner must be wary of relying too heavily on any single physical finding, but instead consider all the variables that influence and alter the history and physical examination as summarized in Table 4. These variables include the reliability of the history, the history of previous infections, the age of the child, the appearance of the EAC, and the appearance and mobility of the TM. The importance of a correct diagnosis is crucial because of the immediate treatment and follow-up dictated by the diagnosis and because of the potential long-term effects on the child's health and development, which are described in the remaining articles in this issue of Pediatric Annals.

REFERENCES

1. Teete DW, Klein JO, Rosner B, et al. Middle-ear disease and the practice of pediatrics: burden during the first 5 lean of life. MWA. 1983; 249: 1 026- 1029.

2. Feigin RQ Kline MW, Speclor G. Otitis media. In: Feigin Rn Cherry JD. ed. Teübooit of ftdúnric Infectious Diseases. 2nd ed. Philadelphia, Pa: WB Saunders Co; 1987:197-270.

3. Bluestone CD. Modem management of ocitis media. Pediarr CIm North Am. 1989;36:?371-13T7.

4. milestone CU Stool SE, Scheetz MD. Pediatrie Otoíaryngoiogy 2nd ed. Philadelphia. Pa: WB Saundets GJ; 1990.

5. Schwäre RH, Rodríguez WJ, Brook I, Gmndfesi KM. The febrile response in acule otitis media. MMA. 198 !i245:205 7 -2058.

6. Mortimer EA, Watterson RL. A bacteriological investigation of otitis media in infancy, Pediatrics- 1956;17:359-366.

7. Howie VM, Schwanz RH. Acute otitis media: one year in general pediatrie practice. Am J Dis Child. 1983;137:155-I58.

8. Bodor FH Conjunctivitis-otitis media syndrome: more than meets the eye. Contemporary Pediatrics. 1989;6:55-60.

9. CavanaughRM. Pneumatic otoscopy in healthy fiill-term intuits. Pediatrics. 1987:79:520523.

TABLE 1

Causes of Otalgia in Children*

TABLE 2

Causes of Otorrhea in Children*

TABLE 3

Physical Examination of the Tympanic Membrane

TABLE 4

Factors Altering the Appearance of the Tympanic Membrane Not Associated With Acute Otitis Media

10.3928/0090-4481-19911101-06

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