Pattern of Otitis Externa in ENT Outpatient Department of BSMMU, Dhaka, Bangladesh

Abstract

Introduction: Otitis externa is an acute or chronic reaction of the whole or a part of the skin of the external ear arising from local or general causes or a combination of both. It is a widespread medical problem affecting 5%–20% of patients who visit otolaryngologists in the tropical and subtropical regions. Objective: This study assesses the pattern of otitis externa in the ENT Outpatient Department. Methods: A prospective study was carried out in the Outpatient Department of Bangabandhu Sheikh Mujib Medical University (BSMMU) among 200 patients (220 affected ears) with the aural symptoms suggestive of otitis externa and 110 healthy controls (220 ears) from July 2002 to December 2003 to find out the pattern of the disease among patients suffering from otitis externa in Bangladesh. Results: The maximum number (35%) of patients were within the 21–30 age group. Most patients were male (56%), with a male-female ratio of 1.3:1. The higher numbers of patients fall within the lower- and middle-income family groups (up to 2,500 and 3,501–4,000 taka per month, respectively). Most patients (30%) were laborers, and most patients were literate. The majority lived in a paka (44%) or semi-paka (38%) house and used tap water for bathing (53.5%). Most patients used cotton buds (49%) for cleaning of ears. Otitis externa was primarily found in the summer and rainy season (69%), with maximum occurrence during June (18.2%) and July (16.4%). In most patients, symptoms persisted for less than two months (76.3%), of which itching, pain in the ear, and a sense of blocking are the commonest triad of symptoms. Itching is the predominant symptom (98.2%) in fungal otitis externa, and pain is the dominant symptom (92.8%) in the bacterial type. Acute infection is commonly painful, whereas chronic disease is mostly itchy. The right ear was more involved (60%) than the left one, and the ear canal was more commonly diffusely involved (84.5%). Among the predisposing factors for the causation of otitis externa, ear cleaning by self or others ranked in the top 42 causes, 7% of the list. It was mainly associated with acute cases. The fungus was isolated from the affected ear in most instances (49.1%), followed by bacteria (31.8%). Moreover, bacteria were often associated with acute cases, and fungus was found more in chronic cases. Aspergillus was found in 89.7% of the fungal species, and Candida was found in 7.5% of cases. Pseudomonas was the predominant organism (40%), and Staphylococcus was the second most common (37.1%) among the bacterial species isolated. The microbiological finding among the healthy controls showed that the external ear canal is less commonly harboring pathogenic organisms. Bacteria were isolated from 18.2% of cases, and fungus was isolated from only 6.3%. Conclusion: From this study, it is also evident that although bacteria could be detected from control cases, fungus isolation was negligible. Most of the bacteria were normal commensals. On the other hand, in the diseased ear, the presence of fungus in the ear canal was highly significant (p < 0.001), which signifies the prerequisite of an altered aural flora and fauna for the development of fungal infection.