Otomycosis

Otomycosis, also known as fungal otitis externa, is an infection of the external auditory canal caused by fungi. It occurs when the normal defenses of the ear canal are disrupted, allowing colonization and growth of fungi, most commonly Aspergillus species (such as Aspergillus niger) or Candida species. It is more common in warm, humid climates and after swimming or sweating. Risk factors include recent antibiotic use, eczema of the ear canal, excessive ear cleaning, immunosuppression, and perforated tympanic membrane.

Symptoms typically include itching, a sense of fullness or pressure in the ear, reduced hearing, and sometimes discharge that may be dull or foul-smelling. Pain is possible but not universal. On examination, there may be crusting or debris in the canal that can be white, gray, or black; surrounding tissues may be inflamed. Diagnosis is primarily clinical, supported by microscopic examination of ear canal debris showing fungal elements; culture can help identify the species. It should be distinguished from bacterial otitis externa and from malignant otitis externa in high-risk patients.

Treatment consists of removing fungal debris through careful cleaning of the ear canal by a clinician, followed by the use of topical antifungal drops such as clotrimazole, miconazole, or natamycin. Some regimens include agents to reduce inflammation; therapy should be chosen with consideration of perforation status, as certain ear drops can be ototoxic if the tympanic membrane is ruptured. Systemic antifungals are rarely needed.

Prevention focuses on keeping the ear dry after swimming, avoiding insertion of objects into the ear, and managing skin conditions of the canal. Recurrence is common in humid environments, so preventive measures after water exposure may be beneficial.