Objectives: Otomycosis or Fungal Otitis External is a superficial infection of the outer ear canal. This could lead to complications involving the middle ear. The prevalence of otomycosis has been studied in several parts of the world. It is seen more frequently as an opportunistic infection in Immunocompromised people and those with ear injury. This study was carried out to determine for the first time, the prevalence of otomycosis in patients attending the Ear, Nose and Throat (ENT) Clinics at Abia State University Teaching Hospital (ABSUTH), Aba, South Eastern Nigeria and to isolate and characterize fungal agents responsible for otomycosis.
Methods: A total of 380 patients presented at the ENT Clinics during the period of study. Out of this number, 100 samples were collected from those patients who presented with symptoms of ear infection (pruritis, otalgia, otorrhea and hypacusis) by the ENT Consultant Physician. Patients with other types of ear disorders other than otitis media and otitis externa and patients under antibiotic therapy within the last 2 weeks were excluded from the study. Demographic characteristics of the patients were noted. The samples which consisted of swabs and scrapings were examined in 10% potassium hydroxide solution and cultured on Sabouraud Dextrose Agar containing Chloramphenicol. Fungal growth were identified using slide culture techniques and physiological tests which include growth on some cspecialized media, germ tube test, urease test, growth in Corn Meal Agar Containing Tween 80, nitrate assimilation, sugar assimilation and sugar fermentation tests.
Results: Out of the 100 samples examined, (68% males and 32% females)were positive for fungal structures both in microscopy and culture. Males were significantly more affected than females in the ratio of 19: 4 (P<001). Although ear infection was highest within the age group 1-10 years, fungal infection was highest within the age group 31- 40 years. Otomycosis was highest amongst outdoor, unskilled labourers (8%), followed closely by students (6%) and lowest among civil servants (2%). The aetiologic agents isolated were Candida albicans (13%), Candida tropicalis (5%), Aspergillus fumigatus (3%) and Aspergillus niger (2%).
Conclusion: This study has shown for the first time that fungi are implicated in ear infections in ABSUTH. The prevalence of otomycosis in the present study is high. Clinical follow up with mycological diagnosis are important since symptoms (pruritis, otalgia, otorrhea and hypacusis) are not specific. In fact many cases of otomycosis are clinically misdiagnosed as otitis media leading to chronicity.Laboratory diagnosis and management of otomycosis though challenging is very important. This is to detect the causative organism and avoid wrong prescription of drugs. Recurrences are common in immunocompromised patients than in immunocompetent patients. General practitioners, otologists and laboratory personnel should remain alert for otomycosis. Diagnosis of ear infections should not be made on clinical diagnosis only, it should be confirmed by laboratory diagnosis. Specimens must be collected by an experienced Medical Personnel by aid of otoscope. The frequent use of earphones, pricking the ear with hard objects, and traumatic attacks on the ear are factors that could predispose to otomycosis.
Full conference title:
- TIMM (2019)