Abstract
Otitis externa is a commonly encountered pathology by otorhinolaryngologists, with its incidence reported as 1%. Chronic otitis externa is a relapsing disease, that is often precipitated by a systemic dermatologic pathology, such as allergic contact dermatitis or psoriasis. It can be challenging to treat, as common treatment options can be exhausted, and the underlying disease continues to precipitate infection. We report the case of a 52-year-old gentleman, affected by both psoriasis and long-standing otitis externa which is resistant to all traditional treatments. Due to severe canal narrowing, micro-suctioning was not possible. After exhaustion of all treatment options, we commenced the off-label use of topical Betamethasone Dipropionate 0.064% w/w and Salicylic acid 3.00% w/w, which is typically used topically for psoriasis. After four weeks of Betamethasone Dipropionate/Salicylic acid, our patient returned free from otalgia and otorrhea, with his external auditory canal completely patent and free from infection. This case demonstrates the safe and effective use of Betamethasone Dipropionate/Salicylic acid in the case of recalcitrant psoriatic otitis externa.
Keywords:
Introduction
Otitis externa is a frequently encountered pathology by otorhinolaryngologists, with its incidence reported as 1% [Citation1]. It is an acute inflammation of the external auditory canal, due to bacterial, fungal or non-infectious causes. Non-infectious causes can include psoriasis and atopic dermatitis. The ear has a number of inherent defense mechanisms to prevent against infection. Firstly, the tragus and anti-tragus provide a barrier to prevent macroscopic structures entering the canal. Cerumen within the external auditory canal creates an acidic environment which inhibits micro-organism growth. Alterations in canal epidermis can cause pruritus, and frequent itching can alter the skin-cerumen barrier leading to impaired cerumen production and inadequate epithelial migration which precipitates otitis externa.
Patients present with a spectrum of symptoms which can include otalgia, pruritus, aural fullness, discharge and hearing impairment [Citation2]. On otoscopy an oedematous, erythematous canal with discharge/debris is often seen.
In general, acute otitis externa is managed with a combination of micro-suction and a variety of adjuvant therapies including topical antibiotics (typically fluoroquinolones or aminoglycosides) and steroids, topical glycerine-ichtammol and wicks impregnated with antibiotics/antifungals/steroids.
Chronic otitis externa is a relapsing disease, that is often precipitated by a systemic dermatologic pathology, such as allergic contact dermatitis or psoriasis [Citation3]. Dry, scaly skin with a lack of cerumen and an alkaline environment means that chronic otitis externa can be extremely treatment resistant, and over time progressive canal oedema and accumulation of granulation tissue can lead to stenosis, which ultimately induces more frequent infections and more severe disease [Citation4]. Chronic otitis externa can be challenging to treat as common treatment options can be exhausted, and the underlying disease continues to precipitate infection. This case report discusses a further treatment option that can be added to our armamentarium in the treatment of chronic otitis externa.
Case report
Here we present the case of a 52-year-old gentleman who was initially referred from Dermatology with long-standing otitis externa which was being managed in the community. His past medical history was significant for chronic plaque psoriasis which was controlled on Adalimumab. He was otherwise well with no other co-morbidities.
He experienced severe itch, otorrhea and fluctuating hearing loss, over a nine-year period, which caused him significant distress. This was managed in both the emergency and outpatient department. Micro-suction was attempted on each occasion, however due to canal narrowing, only an 18-gauge suction could be inserted. Adjuvant treatment options, which were utilized multiple times are summarized in Table .
Table 1. Adjuvant treatments employed post micro-suction.
Due to his stenosed canal, it was not possible to visualize his tympanic membrane using otomicroscopy in the outpatient department. Investigations to visualize his tympanic membrane included CT temporal bones and an examination under anesthesia. The tympanic membrane was directly and radiologically visualized with pathology confined bilaterally to his external auditory canals. On examination, his ears remained unchanged from the outpatient department, where oedematous auditory canal epithelium with scaling and canal stenosis were typically seen.
Following an exhaustion of the standard treatment options for otitis externa, we initiated treatment with topical Betamethasone Dipropionate/Salicylic acid. As this is an off-label indication, the pharmacy department were consulted and the patient was consented. Betamethasone Dipropionate/Salicylic acid (Betamethasone Dipropionate 0.064% w/w, Salicylic acid 3.00% w/w) is typically used topically for the treatment of psoriasis, and we used this off-label aurally. Commercially available Betamethasone Dipropionate/Salicylic acid drops which are typically used as a scalp application were prescribed.
After four weeks of Betamethasone Dipropionate/Salicylic acid, our patient returned free from otalgia and otorrhea. On examination his external auditory canal was completely patent and free from infection. He continues to use Betamethasone Dipropionate/Salicylic acid as required.
Discussion
Salicylic acid in combination with corticosteroids is typically used in the treatment of psoriasis, with betamethasone dipropionate and salicylic acid (Betamethasone Dipropionate/Salicylic acid) a frequently used combination. Betamethasone Dipropionate/Salicylic acid reduces scaling, itching and redness associated with psoriasis [Citation5]. However, there is no literature available on the use of Betamethasone Dipropionate/Salicylic acid on the otitis externa in humans. Betamethasone Dipropionate/Salicylic acid (or a different salicylic acid/glucocorticoid combination) has been used in the management of otitis externa in canines with success [Citation6].
Salicylic acid alone can be employed in the treatment of psoriasis, but typically topical corticosteroids are the mainstay of treatment [Citation5]. They bind to cytoplasmic glucocorticoid receptors, reducing prostaglandins, leukotrienes and inhibiting cytokine production. In order for topical corticosteroids to work, they need to cross the stratum corneum, which is the primary barrier to absorption [Citation5]. Salicylic acid augments the action of corticosteroids by reducing scaling and thus providing greater penetration [Citation7]. It acts principally on the stratum corneum by reducing intercellular adhesion between corneocytes, and lowering the pH of the stratum corneum, hence providing hydration and descaling, while also increasing the availability of corticosteroids [Citation8]. Additionally salicylic acid has both bacteriostatic and bactericidal activity against gram-negative and gram-positive bacteria in addition to acting on some yeasts. Betamethasone Dipropionate/Salicylic acid has been shown to relieve itching, reduce inflammation when compared to corticosteroid therapy alone in the treatment of psoriasis [Citation9]. Potential side-effects include headache, tinnitus, nausea and vomiting, but these have only been reported when used over large surface areas and over a long time period [Citation10].
Otitis externa is one of the most frequently encountered conditions by otorhinolaryngologists. The majority of cases resolve after one week of topical antimicrobials, with or without steroids [Citation11]. Patients with symptoms beyond two weeks should commence on alternative management strategies. The latest clinical practice guidelines recommend that after initial treatment failure, the patency of the ear canal should be reassessed to ensure adequate drug delivery, and addressed with aural toilet or wick placement if necessary [Citation12]. There are no recommendations for further treatment options if this is unsuccessful.
Psoriasis can be associated with external auditory canal alterations, typically desquamation and less frequently stenosis, which can disrupt the epithelium of the ear and precipitate bacterial invasion [Citation13]. Cutaneous chronic inflammation and keratinocyte hyperproliferation can lead to canal stenosis, in a similar manner to keratosis obturans. Keratosis obturans has been described as the accumulation of desquamated keratinous material in the bony portion of the external auditory canal [Citation14]. It is typically managed with regular micro-suctioning.
In our case, the initiation of Betamethasone Dipropionate/Salicylic acid led to a wider external auditory canal, which was free form debris. It is imperative to counsel the patient on it’s off label use, and the correct application within the canal itself. This case demonstrates the safe and effective use of Betamethasone Dipropionate/Salicylic acid in successfully treating recalcitrant otitis externa, thus adding another tool in the armamentarium of the treatment of otitis externa.
Ethical statement
Patient consent was obtained and all institutional ethical standards were adhered to.
Informed consent
Informed consent Authors confirm that consent was obtained from the patients for this study.
Disclosure statement
No potential conflict of interest was reported by the author(s).
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