Otomycosis: This is the most common fungal infection of the ear, often caused by Aspergillus or Candida species. It typically presents with symptoms such as itching, discomfort, and a visible fungal growth in the ear canal, making it the most likely diagnosis for bilateral ear fungus.

Seborrheic Dermatitis: An inflammatory skin condition that can affect the ears, leading to flaky skin and potentially resembling a fungal infection. It's a common condition and could be considered in the differential for bilateral ear symptoms.
Eczematous External Otitis: An allergic or irritant reaction affecting the outer ear canal, which could be mistaken for a fungal infection due to similar symptoms like itching and redness.
Psoriasis: A chronic skin condition that can affect the ears, causing redness, scaling, and discomfort, potentially mimicking fungal infections.

Malignant Otitis Externa: A severe infection of the outer ear and skull cartilage, more common in diabetic or immunocompromised patients. Although less common, it's critical to diagnose early due to its potential for serious complications.
Necrotizing Otitis Externa: A dangerous infection that can spread to the temporal bone and skull base, often seen in diabetic patients. It requires prompt recognition and treatment to prevent severe outcomes.

Keratitis due to Fungal Infection: While more commonly associated with the eyes, certain fungal infections can cause keratitis, and in rare cases, might be considered in the differential for ear symptoms if there's an unusual presentation or concomitant eye involvement.
Chronic Mycetoma: A rare, chronic infection caused by fungi or bacteria that can affect various parts of the body, including the ear. It's characterized by granules in the discharge and is more common in tropical regions.