Ear infections are among the most common reasons for visiting outpatient clinics. While most infections are caused by bacteria, otomycosis (otherwise known as fungal otitis externa) is a fungal infection. Fungi thrive in moist, warm environments and the ear provides an ideal location to lay down roots – or should we say hyphae. As the fungi colonize, itching, pain, aural fullness, aural discharge, hearing impairment, and tinnitus begin to plague the sufferer. Fortunately, the infection remains in the external ear canal, but occasionally, will move to the middle ear.
The offender most often belongs to the family Aspergillus, particularly Aspergillus niger; however, Penicillium, Fusarium, Mucoraceae, Scopulariopsis, Alternaria, Malassezia, and Candida have also been known to take up residence in the ear. Fungi are easily acquired while swimming, leading to a condition which has been colloquially termed, swimmer’s ear. Other means of gaining infection can include poor hygiene, living in humid or high-temperature climates, trauma to or inflammation in the ear, epithelial debris, and prolonged use of steroids (which depress immune function) or antibiotics (which disrupts the normal flora of the ear). Anyone with an impaired immune system or with conditions such as diabetes mellitus is at higher risk of developing otomycosis.
Conventional treatments focus on antifungal agents such as azole group antifungals, amphotericin B, boric acid, mercurochrome and phenylmercuric acetate in sterile water, urea-acetic acid solution, or aluminum acetate solution. Unfortunately, resistance to common antifungal agents is becoming a concern and necessitating the discovery of alternative methods of treatment. In a study of 112 patients with otomycosis caused by one or two of 17 different fungal species, all mold species were found to be resistant to the common antifungal agent, fluconazole, and all yeast species were resistant to terbinafine. Further, 94 percent were resistant to itraconazole. Growing resistance may be a problem because fungi are difficult to eradicate (due to biofilms, high enzymatic ability, etc.), making recurrence and long-term use of pharmaceuticals common.
Fungi are difficult to eradicate directly, making vigilant prevention a key to managing this condition. It is well known that immunocompromised individuals are at high risk for recurrent otomycosis; therefore, focusing on building and maintaining a strong immune system is vital. For individuals with diabetes mellitus, stabilizing blood sugar levels will be the single most important step that can help in maintaining a functionally effective immune system and keeping a healthy microbiome.
The microbiome of the gut is a large determinant in the robustness of an individual’s immune system. Further, the flora of the ear canal is also linked to the microbiome of the gut. Not surprisingly the most common infectious agent of otomycosis in immunocompromised individuals is Candida albicans, which is also the most common fungal species found in the gut and known to be associated with dysbiosis and other conditions represented by an unhealthy gut microbiome. Therefore, building a healthy gut microbiome is a foundational element of preventing recurrent ear infections such as otomycosis.
Garlic has been used for centuries as an effective antifungal agent. It has been studied specifically on Candida albicans and Aspergillus and found to be effective where pharmaceutical antifungals were not. Garlic oil was found to be able to penetrate the cell walls and various organelles of Candida albicans as well as modulate gene expression, downregulate proteins, disrupt metabolism, and prevent cell growth. Allicin, the most biologically active compound in garlic, has been shown to be more effective than garlic extract for inhibiting the growth of hyphae, making garlic effective against a wide variety of fungal species. Current research has not focused on the role of garlic in directly treating otomycosis; however, an older in vitro study with the goal of determining the efficacy of garlic in eradicating Aspergillus species associated with otomycosis found that aqueous garlic extract (AGE) and concentrated garlic oil both showed similar or better inhibitory effects than pharmaceutical antifungal agents.
In less humid/tropical climates, otomycosis is probably most often caused by moisture retention from swimming and identified as swimmer’s ear, but there are many other factors that make fungal ear infections common, even among non-swimmers. With rising resistance to antifungal agents, treatment of otomycosis can be difficult. The first line of action should focus on prevention through building a healthy immune system and being aware of the ideal conditions for fungal growth. But once the fungi start to flourish, garlic may be a good option for halting its progression.