As spring spreads across the country, the change in temperature and slanting of the sun promises that summer is soon on its heels. For many primary care physicians and otolaryngologists, particularly those living in northern climes, that means an upsurge in people presenting with acute otitis externa, a condition that is estimated to afflict from 1 in 100 to 1 in 250 persons in the general population.
Explore This IssueJune 2009
For most patients, standard treatment with topical antibiotics or antiseptics is sufficient and safe. For some patients, particularly those with diabetes or conditions that compromise their immune system, treatment can be more complex, as these patients are at higher risk of complications.
For most otolaryngologists, diagnosis and treatment of this condition is fairly straightforward, according to Peter S. Roland, MD, Professor and Chairman of Otolaryngology-Head and Neck Surgery at UT Southwestern Medical Center in Dallas, who coauthored the clinical practice guidelines on acute otitis externa endorsed by the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS; www.entnet.org/Practice/upload/AOE-cpg.pdf ).
Dr. Roland emphasized, however, that otolaryngologists need to pay special attention to particular populations of patients in whom this condition may wreak more havoc and be more difficult to treat. And perhaps the most important message to otolaryngologists is the need to recognize the potential toxicity of one of the most widely used topical antibiotic agents used as first-line therapy.
The guidelines recommend that ototoxic topical antibiotics be avoided unless people are reasonably confident that the eardrum is intact, he said.
Along with these special treatment considerations, otolaryngologists need to pay attention to pain as a diagnostic indicator of potential risk of complicated swimmer’s ear and as an important factor to treat for optimal management.
Importance of an Intact Eardrum to Avoid Ototoxicity
Standard treatment for uncomplicated, straightforward cases of acute otitis externa is the use of either an antiseptic or an antibiotic topical agent. All the currently used agents in both categories are largely safe for most patients. However, ototoxicity has been reported in patients treated with aminoglycosides (neomycin, gentamicin, tobramycin) if the drops get into the middle ear space through a puncture in the eardrum and are absorbed into the inner ear.
The determining factor for the risk these agents pose is whether the eardrum is intact or not. If the eardrum is intact, these agents are not toxic, said John A. Rutka, MD, Professor of Otolaryngology-Head and Neck Surgery at the University of Toronto, who has been on the forefront of writing on the potential ototoxicity of these agents.
If the eardrum is not intact, however, he recommends the use of a floroquinolone topical agent combined with a steroid. Floroquinolones, although not contraindicated as first-line therapy, cost more than the other topical agents; therefore, Dr. Rutka emphasized the need to consider their cost if other therapies are equally efficacious.
Despite reports on ototoxicity with the aminoglycoside agents, these agents continue to be widely used as first-line treatment for acute otitis externa, according to Dr. Roland. Although he has not personally used these agents for more than 20 years to treat this condition, as he uses quinolone drops, he said that the continued use of these agents is largely based on their cost-they are cheaper than the other agents.
For otolaryngologists who continue to use these potentially ototoxic agents, it is critical that they assess whether or not the eardrum is intact. Although visual examination can show this, in many patients this is not possible, given the severe swelling in the ear. In these patients, assessment should include a history of the patient that includes information on past history of perforated eardrum, tubes in the ear, or questions that can help identify with reasonable certainty that the eardrum is intact.
According to Gerard J. Gianoli, MD, an otolaryngologist at the Ear and Balance Institute in Baton Rouge, LA, however, otolaryngologists have been using these antibiotic agents for decades, even in patients with a hole in their eardrums. From a practical standpoint, these patients often have so much swelling that the antibiotic never gets into the middle ear, even with a hole in the eardrum, he said. Many otolaryngologists have never seen a case of toxicity even in these patients, while others have seen a couple cases that have scared them. Prudence dictates avoiding the use of ototoxic drops when the eardrum is not intact, especially since there are now good alternatives that weren’t available in prior decades.
Despite the long practice of using antibiotics in patients even with perforated eardrums, the new practice guidelines recommend avoiding these antibiotics if a perforated eardrum is suspected.
Regardless of the type of agent, many otolaryngologists recommend the addition of a steroid to reduce the swelling to allow the topical agent to penetrate to the middle ear, as well as to more quickly reduce pain. For patients with considerable swelling, the topical agents should be delivered on the tip of a wick inserted into the ear to ensure that the agent reaches the middle ear.
According to Dr. Rutka, one of the main reasons for treatment failure is the excessive swelling that prohibits the topical agent from contacting the entire external auditory canal. The use of a wick acts as a hygroscopic agent and vehicle carrier that will draw fluid from the inflammation but will also allow the drops to get down [the canal], he said.
Pay Attention to Pain
Critical to the accurate diagnosis and optimal treatment of a patient with swimmer’s ear is consideration of the degree of pain the person is suffering. According to Alan Micco, MD, Chief of Otology and Neurotology at Northwestern University in Chicago, inordinate pain should alert the otolaryngologist that a patient may have a more complicated case of otitis externa.
Malignant otitis externa or necrotizing otitis externa, the most serious complication, occurs when the bacterial infection gets into the middle and inner ear and spreads to the bone at the base of the skull. Although rare, the seriousness of the complication can be fatal; therefore, swift and accurate diagnosis and treatment with oral antibiotics is necessary.
People at increased risk of this complication are those with diabetes and those with compromised immune systems from diseases such as HIV or from treatment such as chemotherapy. People with these risk factors who present with otitis externa should be screened and treated more aggressively. Although it is generally not used to treat otitis externa, irrigation of the ear for wax buildup, which may predispose a person to developing otitis externa, is ill advised particularly in people with diabetes, given reports of malignant otitis externa developing in these patients after ear irrigation with tap water.
Another complication that can occur, particularly after prolonged use of topical antibiotic and steroidal drops, is a secondary fungal infection. What typically happens is that the acute pain goes away and then the ear becomes blocked and itchy, said Dr. Rutka, adding that this can be treated by cleaning out the ear and stopping the use of the drops. In some cases, he said, antifungal treatment may be required.
Along with using pain as a guide to accurate diagnosis, controlling pain should also be a critical part of treatment. Dr. Rutka recommends including pain medication with an oral anti-inflammatory such as Celebrex.
For people who are prone to or frequently develop acute otitis externa, Dr. Gianoli recommends a rinsing out the ears with a home brew of one part rubbing alcohol and one part white vinegar. The alcohol helps desiccate the ear, and the vinegar acidifies the ear and prevents the bacteria from getting a foothold, he said, adding that the solution should be at body temperature to avoid an inadvertent caloric test.
Physicians should also be aware that recurrent problems may be a sign that the person has an underlying condition, such as diabetes, said Dr. Rutka.
Need to Educate Primary Care Physicians
Although most otolaryngologists use topical agents to treat swimmer’s ear, oral antibiotics are still widely used in the primary care setting by physicians who are most often the first to see these patients. Although some feel this is overtreatment, for others it is seen as a completely ineffective treatment. The main bacteria that causes otitis externa is Gram-negative bacteria, and there are very few oral agents effective against Gram-negative bacteria, said Dr. Rutka. Unless there is a spread of infection outside of the ear canal and there is consideration of an infection with Gram-positive bacteria as well, you wouldn’t use an oral antibiotic.
Dr. Roland pointed out that getting the guidelines into the hands of primary care physicians may have the greatest impact of significantly improving care of this condition.
©2009 The Triological Society