Topical and systemic treatment for chronic suppurative otitis media.

Chronic suppurative otitis media (CSOM) is caused by (1) an infection that traverses the outer ear canal and enters the middle ear through a perforation or (2) an infection that originates in the nose, sinus, or particularly the pharynx, especially in children, and reaches the middle ear cleft via the eustachian tube. CSOM might also originate as a consequence of acute otitis media that does not fully resolve for some local or systemic reason. CSOM is known to be a relapsing disease, and recurrences might be caused by smoldering infections in the retrotympanic spaces, such as the mastoid air cells.

Complications of CSOM

In considering the different therapeutic options, the physician must be aware of the complications that can arise. CSOM can cause chronic mastoiditis, which initially affects the small bony ridges in the mastoid. If not properly treated, the inflammation can penetrate through the mastoid cortical bone behind the ear; even worse, it can enter the intracranial space and cause meningitis or an intracranial abscess. A more common complication of relapsing CSOM is a deterioration of cochlear function.

Most patients with long-standing CSOM have a combined sensorineural and conductive hearing loss. We do not know if this hearing loss is mediated by a toxin or by treatment with an ototoxic drug. These potentially serious complications should prompt us to treat CSOM aggressively.

Literature review

In 1999, researchers in Spain reported their study of 125 patients who had CSOM as a result of infection with either Pseudomonas aeruginosa, Staphylococcus aureus, or Enterobacteriaceae. (1) This study included five treatment arms: (1) 500 mg of oral ciprofloxacin every 12 hours, (2) 3 drops of topical ciprofloxacin/hydrocortisone 0.5% every 8 hours, (3) 3 drops of topical ciprofloxacin 0.2% every 8 hours, (4) a combination of the oral and topical 0.2% ciprofloxacin regimens, and (5) topical neomycin/polymyxin B (control group). The most effective treatment proved to be the topical 0.2% ciprofloxacin regimen.

In 1996, Smith et al reported a study of 524 African schoolchildren (age range: 5 to 15 yr) with CSOM. (2) Patients were randomly assigned to one of three groups: (1) no treatment, (2) dry mopping of the ear alone, or (3) dry mopping plus topical and systemic antibiotics and topical steroids. Assessments were made at 8, 12, and 16 weeks post-treatment by otoscopy, tympanometry, and audiometry. The authors found that the third treatment arm experienced the best rate of symptom resolution. However, the authors did not address the issue of whether topical and/or systemic therapy is necessary.

In a study from Thailand, 80 adults with CSOM were treated with either topical ofloxacin 0.3% at 6 drops twice daily or oral amoxicillin at 500 mg three times daily plus topical chloramphenicol 1% at 3 drops three times daily. (3) The ofloxacin regimen was significantly better in resolving pain and otorrhea. It was also better in terms of the overall improvement rate, although the difference was not statistically significant.

In another study from Thailand, topical ciprofloxacin was compared with normal saline solution in 35 patients with CSOM. (4) Symptom relief at 7 days' follow-up was seen in 89.5% of the ciprofloxacin group and only 43.8% of the saline group.

In Italy, researchers compared topical ciprofloxacin with intramuscular gentamicin in 60 adults with CSOM. (5) A favorable clinical result was seen in 86.7% of the ciprofloxacin group and in 66.7% of the gentamicin group.

A study of 56 patients in Hong Kong revealed that topical ofloxacin 0.3% was more effective than amoxicillin/clavulanate in resolving CSOM. (6) Treatment success rates were 75.9 and 25.9%, respectively.

In 2000, Acuin et al published a meta-analysis of 24 trials that included 1,660 patients. (7) Although there were significant differences in the methods of diagnosis and follow-up among these studies, the authors concluded that topical antibiotics were superior to systemic agents and that combining the two was no more effective than topical therapy alone. Moreover, topical fluoroquinolones were more effective than other topical antibiotics. Interestingly, there was no difference in effectiveness between topical antibiotics and topical antiseptics.

Finally, the American Academy of Otolaryngology--Head and Neck Surgery sponsored a consensus conference in 1999 on the use of topical antibiotics in treating three common ear diseases, including CSOM. (8) The expert panel concluded that "in the absence of systemic infection or serious underlying disease, topical antibiotics alone constitute first-line treatment for most patients...." The panel found no evidence that systemic antibiotics, alone or in combination with topical agents, are any more effective than topical agents alone. The group recommended that systemic antibiotics be added to topical therapy only for patients who have enlarged lymph nodes, hearing aids, or signs of general infection and for those who are immunocompromised.

One drawback of some topical therapies is that they can cause a contact-allergy reaction. A study of 34 patients in the Netherlands revealed that the rate of allergic reactions was 56% with topical aminoglycosides and 50% with topical gentamicin. (9)

My personal approach to treating uncomplicated CSOM is to clean the ear under the microscope, take a swab, and administer a topical quinolone, not an aminoglycoside. If the patient does not respond, I switch to culture-directed therapy, first topical and later systemic if necessary. For cases that are still resistant, I proceed to a canal-wall-up mastoidectomy.

Comments

Prof. Van de Heyning: We conducted our own study in Belgium of oral ciprofloxacin for the treatment of CSOM. We found that many patients were cured clinically but not bacteriologically. This adds further support to the idea of using topical therapy. We also investigated the incidence of ototoxicity in patients who received topical ciprofloxacin. We could not find any evidence that topical ciprofloxacin caused any ototoxicity or hearing loss, either conductive or sensorineural. Our findings have been confirmed in subsequent studies.

Dr. Schapowal: In 2000, our institution conducted a study of 62 patients with chronic eczema or recurrent otitis externa who had been treated with antibiotic eardrops at least once in their lives. (10) To determine if we could identify the cause, we conducted patch testing on the skin of each patient's back. We found that 12.9% of patients experienced an allergic reaction to neomycin drops, but 0% reacted to ciprofloxacin drops. Combined with its high degree of therapeutic efficacy, ciprofloxacin's lack of ototoxicity gives it a clear advantage over neomycin-containing products.

References

(1.) De Miguel Martinez I, Vasallo Morillas JR, Ramos Macias A. [Antimicrobial therapy in chronic suppurative otitis media]. Acta Otorrinoloringol Esp 1999;50: 15-9.

(2.) Smith AW, Hatcher J, Mackenzie IJ, et al. Randomised controlled trial of treatment of chronic suppurative otitis media in Kenyan schoolchildren. Lancet 1996;348:1128-33.

(3.) Supiyaphun P, Kerekhanjanarong V, Koranasophonepun J, Sastarasadhit V. Comparison of ofloxacin otic solution with oral amoxycillin plus chloramphenicol ear drop in treatment of chronic suppurative otitis media with acute exacerbation. J Med Assoc Thai 2000;83:61-8.

(4.) Kasemsuwan L, Clongsuesuek P. A double blind, prospective trial of topical ciprofloxacin versus normal saline solution in the treatment of otorrhoea. Clin Otolaryngol 1997;22:44-6.

(5.) Esposito S, Noviello S, D'Errico G, Montanaro C. Topical ciprofloxacin vs intramuscular gentamicin for chronic otitis media. Arch Otolaryngol Head Neck Surg 1992;l18(Suppl 8):842-4.

(6.) Yuen Pw, Lau SK, Chau PY, et al. Ofloxacin eardrop treatment for active chronic suppurative otitis media: Prospective randomized study. Am J Otol 1994;15:670-3.

(7.) Acuin J, Smith A. Mackenzie I. Interventions for chronic suppurative otitis media. Cochrane Database Syst Rev 2000;(2): CD000473.

(8.) Hannley MT, Denneny JC III, Holzer SS. Use of ototopical antibiotics in treating 3 common ear diseases. Otolaryngol Head Neck Surg 2000;122:934-40.

(9.) Van Ginkel CJ, Bruintjes TD, Huizing EH. Allergy due to topical medications in chronic otitis externa and chronic otitis media. Clin Otolaryngol 1995;20:326-8.

(10.) Schapowal A. Contact dermatitis to antibiotic car drops is due to neomycin but not to ciprofloxacin [abstract]. Allergy 2001; 56(Suppl 68):148.

Thomas Deitmer, MD, PhD

Prof. Deitmer is head of the Department of Otolaryngology at Klinikum Dortmund Teaching Hospital in Dortmund, Germany. Like all otolaryngologists in Germany, he is a generalist.