Last updated on April 25th, 2023 at 11:45 am
Otomycosis is a fungal infection of the ear, and the most frequently encountered fungal infection in ear, nose and throat clinics. The organisms responsible for otomycosis are usually fungi from the environment, most commonly Aspergillus niger. The fungi usually invade tissue that has already been damaged by bacterial infections, physical injury or excess earwax.
- Itching, irritation, discomfort or pain
- Small amounts of discharge
- A feeling of blockage in the ear
In rare cases, Aspergillus infecting the ear may spread to bone and cartilage, causing a severe and life-threatening disease. This is more frequently caused by Aspergillus fumigatus than Aspergillus niger, and is associated with underlying immunocompromisation, diabetes mellitus or patients on dialysis.
A diagnosis of otomycosis is confirmed by taking debris from the infected ear, culturing it on a special agar plate and using microscopy to establish the causative organism. If the infection is deep, a biopsy should be taken for fungal culture and identification. If there is a suspicion of the infection becoming invasive, CT and MRI scans can be used to see whether the fungi has spread to any other sites.
Treatment involves carefully drying and cleaning the ear canal, using microsuction. Aural syringing should be avoided as it can lead to the infection flaring up in deeper sites of the ear. Depending on how complicated the infection is, you may need to further treat with antifungals applied to the ear. Treatment should continue for 1-3 weeks and oral antifungal therapy is only required if the antifungals applied to the skin do not work, or the condition is invasive.
With good ear canal cleaning and antifungal therapy, otomycosis is usually cured and does not relapse.
Onychomycosis is a fungal infection of the nail, most commonly the toenail. Fungal nail infection is common in the general adult population, with a rate of about 5-25% and increasing incidence in elderly people. Onychomycosis makes up about 50% of all nail disease. There are a wide variety of fungi that can onychomycosis, but T. rubrum is responsible for about 80% of cases in the UK. Aspergillus species, amongst many other fungi, can occasionally cause onychomycosis. Some infections are caused by more than one fungus.
Symptoms of the infection will vary depending on the type of fungus involved, but thickened nails and discoloration are common.
Some of the contributing factors causing this disease are occlusive footwear, extensive water contact with nails, repeated nail trauma, genetic predisposition and concurrent disease, such as diabetes, poor peripheral circulation and HIV infection, as well as other forms of immunosuppression.
Diagnosis of the causative fungus is achieved by scraping the nail (the material under the nail is the most rewarding material). Small pieces of this are then inspected under a microscope and grown on special agar plates to determine the species responsible for the disease.
Treatment depends on the causative species and the severity of the disease. Antifungal cream or ointment applied to the affected nail is effective in some milder cases. Oral antifungal therapy or surgery to remove the nail may be required. Treatment can last from 1 week to 12+ months, depending on the case. Cure is possible, but takes a long time, as the growth of nails is slow.
The nail fold can also become infected – this is called paronychia, and is usually caused by Candida albicans and other Candida species.
Fungal keratitis is a fungal infection of the cornea. The most common causative agents are Aspergillus flavus, Aspergillus fumigatus, Fusarium spp. and Candida albicans, although other fungi can be responsible. Trauma, especially if associated with plant material, is a common antecedent to fungal keratitis. Contact lens fluid contaminated with fungi can also cause fungal keratitis. Other possible risk factors include topical corticosteroids, traditional medicines and higher external temperatures and humidity. Bacterial keratitis is more common in contact lens wearers and the western world, whereas in India and Nepal and some other countries, fungal keratitis is at least as common as bacterial keratitis. There are estimated to be over a million cases of fungal keratitis annually worldwide, mostly in tropical countries.
ymptoms are usually like other types of keratitis, but perhaps more prolonged in duration (5-10 days):
- eye redness
- excess tears or other discharge from your eye
- difficulty opening your eyelid because of pain or irritation
- blurred vision
- decreased vision
- sensitivity to light
- a feeling that something is in your eye
The best way to diagnose fungal keratitis is to take a scraping of infective material from the cornea. Any fungal agent in this scraping is then grown on a special agar plate for identification. Along with culturing the organism, microscopy is required due to the wide variety of potential causative fungi.
Antifungals applied directly to the eye in the form of eye drops are essential for the treatment of fungal keratitis. The frequency at which they are administered depends on the severity of the infection. In severe cases this is hourly, and can be reduced in frequency after 1 day as improvement is documented. Topical antifungal therapy has a 60% response rate with retention of vision if keratitis is severe and a 75% response if milder. For severe infections, oral therapy is also advised. The antifungal treatment given depends on the causative species. Therapy is usually continued for at least 14 days. Surgical debridement is essential for severe disease.
Fungal keratitis is associated with a ~5- fold higher risk of subsequent perforation and need for a corneal transplant than bacterial keratitis. Recovery of sight is higher if the diagnosis is made early.