Generalist pediatricians can expect to diagnose and treat at least 15 children with otitis externa during the swimming season. Most of the children will have mild or moderate otitis externa. Management of such children is straightforward and usually includes avoidance of water in the ear canal and instillation of otic drops containing either dilute acetic acid or one or more ototopical antibiotics with or without hydrocortisone suspension.
Diagnosis and management of severe otitis externa is often neglected in outpatient pediatric training and we often learn how to manage this painful condition from our otolaryngology colleagues.
Symptoms of severe otitis externa include intense otalgia, often unrelieved by acetaminophen or ibuprofen analgesics. Exquisite pain is elicited when the auricle is wiggled or when an object is inserted into the external auditory meatus. There are major interruptions of sleep and normal activity is curtailed because of the severity of the pain. The child is miserable and parents often feel helpless.
Prominent external physical signs of severe otitis externa include impressive stenosis caused by boggy edema of the ear canal and even the auditory meatus and intense erythema of the skin of the canal wall. Gentle otoscopy reveals that there is desquamation of the skin. When combined with bacteria and inflammatory exudate from the infection, it causes a soggy mess, which obscures the canal lumen. When the canal edema subsides enough to see the tympanic membrane, it usually looks reddened, with plaques of desquamating shaggy epithelial plaques noted on its surface.
Unless the tympanic membrane is bulging and poorly mobile, there is no need to diagnose acute otitis media and usually no need to prescribe orally administered antibiotics. The external auditory canal is a tube with the tympanic membrane (TM) at the bottom. Whatever happens to the canal walls is likely to extend to the lateral surface of the TM, giving it a superficial appearance of acute otitis media but in reality, only a myringitis. The differential diagnosis includes chronic otorrhea secondary to chronic otitis media. However, the acute onset, the intense pain, the pipe cleaner narrowing of the ear canal and the association with swimming are clues to differentiation between the two.
In the worst cases, there may even be edema and erythema of the auricle, the pre-auricular area of the face, and rarely, the skin over the mastoid area. Management of these challenging cases involves several steps.
Step one involves pain relief. A moderately potent analgesic such as acetaminophen with codeine (1.0 mg/kg/dose of the codeine component) or an injection of morphine (0.1 mg/kg/dose, IM), or ketorolac (0.4 - 1 mg/kg/dose, IM) will be much appreciated by your suffering patient. The first dose should be given in the office about 20 minutes prior to the otoscopic examination.
Step two should be gentle, but thorough, aural lavage using warm water, warmed hypertonic (3%) buffered saline, or 2.5% acetic acid solution made by combining equal parts of white vinegar and water. Otolaryngologists tell us that omission of this critical step is one of the most frequent reasons for failures. Soft debris left in the canal after lavage may be removed with gentle "mopping" using a curette wrapped with a small wisp of absorbent cotton, which is changed after each swabbing. Careful suction using a suction tube, metal suction catheter, or infant bulb syringe may be helpful.
Step three is the insertion of one of the commercially available otowicks into the ear canal. These methylcellulose wicks which can be cut to size, expand when they are moistened by aqueous solutions, thereby reducing ensuring contract of the antibacterial otic product with the inflamed walls of the ear canal. Corticosporin solution or acetic acid-propylene glycol solution (Vosol, by Wallace, will not penetrate the wick unless preceded by an aqueous solution. The wick remains in place until it is removed by the physician or, if healing is rapid, by the parent. These wicks cost several dollars each, but are better than using cotton because cotton is too flimsy. The stiffness of the wick helps with insertion).
Step four is the elimination of the infection and reduction of inflammation in the ear canal. Most otolaryngologists prefer to use 2% acetic acid solution such as Domeboro otic, four to six drops instilled directly into the ear canal or the lumen of the otowick every two waking hours for the first day or two. Use of homemade 2.5% acetic acid solution consisting of equal parts of white vinegar and water, or rubbing alcohol, are equally effective and far less costly (Domeboro can cost as much as $40).
Step five is the instillation of ototopical antibiotic drops into the ear canal. Antibiotic drops are usually necessary in the more severe cases of otitis externa and many physicians prefer them in place of dilute vinegar or Domeboro otic for less severe cases.
Step six is education. The parent should take precautions to keep water out of the external ear canal by using commercial silicon earplugs or a shower cap when bathing. The child may return to swimming when there is no more canal wall edema and no more pain with tragal wiggling. We suggest the use of prophylactic dilute acetic acid solution after getting out of the pool before lunch and in the afternoon.
When there is extension of the inflammatory process to the auricle or mastoid area, or when the child is febrile, oral antibiotics may be necessary. Neomycin-containing antibiotic drops occasionally may cause a severe contact dermatitis, which confuses the situation. We have prescribed infrequently, a course of oral fluoroquinolone antibiotics after explanation of the risks and potential benefits to the parent. Although not approved by the Food and Drug Administration for use in children younger than 18 years, judicious use in cases of very severe otitis externa has been gratifyingly successful and may avoid progression of the otitis externa.
Malignant otitis externa occurs when there is extension of the infection to the perichondrium of the cartilaginous portion of the ear canal. It is classically associated with severe otitis externa in immunocompromised children including those with diabetes mellitus, those with leukemia receiving chemotherapy, and HIV infection. This dangerous condition usually necessitates hospitalization and treatment with IV antibiotics.
After successful reduction of pain and edema, ototopical antibiotic drops are substituted for the 2.5% vinegar solution. The major pathogen of otitis externa is Pseudomonas aeruginosa, causing 90% or more cases of severe otitis externa. We have successfully used one of the fluoroquinolone otic drops (ciprofloxacin, by Bayer, with or without hydrocortisone, or ofloxacin otic drops) which have excellent antipseudomonas coverage with convenient twice-daily (BID) dosing. Cure rates can be expected after five to seven days of treatment. Polymyxin B-containing otic drops can also be used but require four-times daily (QID) dosing.
Mild to moderate external otitis can generally be treated at home. However, in severe otitis externa, unless there is dramatic improvement of the child's condition, daily office visits are necessary until substantial improvement occurs. At the re-evaluation visit, another gentle lavage of the ear canal is usually performed to remove additional desquamated skin. Aural hygiene is a major key to successful treatment. If there is still substantial canal edema, a second otowick is inserted.
Management of severe otitis externa should be in the province of the pediatric generalist. By following an individualized graded treatment plan such as the one above, there should be fewer failures. You can expect a great deal of gratitude from successfully treated patients for you will have relieved their misery.
For more information:
- Calderon R, Mood EW. An epidemiologic assessment of water quality and "swimmer's ear." Arch Environ Health. 1982. 37: 300-4.
- Dohar JE, Garner ET, Nielsen RW, et al. Topical ofloxacin treatment of otorrhea in children with tympanostomy tubes. Arch Otolaryngol Head Neck Surg. 1999. 125: 537-45.
- Canto RM. Otitis externa and otitis media: a new look at old problems. Emerg Med Clin North Am. 1995. 13: 445-55.
- David NF. Topical therapeutics for otitis media. Otolaryngol Head Neck Surg. 1981. 89: 381-5.
- Angius AM, Pickles JM, Burch KL. A prospective study of otitis externa. Clin Otolaryngol. 1992. 17: 150-6.
- Crowther JA, Simpson D. Medical treatment of chronic otitis media: steroid or antibiotic with steroid ear drops. Clin Otolaryngol. 1991. 16: 142-4.
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