The 7-step approach to managing otitis (Proceedings)

My goal is to provide you with a set of questions to guide you through the pitfalls and obstacles associated with diagnosing, treating and successfully managing canine and feline otitis cases. Let's get started!

Is this a case that should be managed medically or surgically?

Gentle manipulation of the pinnae and the annular cartilage will allow you to make this determination. If the tissue is fibrous and completely non-flexible it is highly unlikely that medical management will resolve this condition. The only intervention that will "dissolve" or remove calcified ear cartilages is surgical in nature. That being said, not all patients should have bilateral TECA-BO at birth, despite their breed predilection for chronic and severe ear disease. We see many cocker spaniels and poodles that do not have any evidence of otitis. In addition, dogs with first-time cases of otitis are not likely to require surgical treatment unless neoplasia or a foreign body is contributing to the condition.

What is the neurologic status of the patient? Additional methods to assess integrity of the ear cartilages as well as condition of the tympanic cavity and related structures include radiographs, CT scans and magnetic resonance imaging. Advanced imaging techniques provide additional diagnostic information as well as prognostic information for outcome, especially if there is uncertainty regarding need for surgery.

Is the otitis unilateral or bilateral in presentation? What is the age of presentation?

A unilateral case of otitis is unusual and prompts further investigation into potential underlying causes.
     √ If the patient is young: consider a foreign body, hypothyroidism, CARF (cutaneous adverse reaction to food)
     √ If the patient is older: in addition, consider neoplasia sooner rather than later!

Atopic dermatitis can also present as a unilateral otitis, however the age of onset (1-6 years of age, typically) and additional clinical signs, such as a seasonal component, are expected. Hyperadrenocorticism can also contribute to otitis, especially if calcinosis cutis lesions form in the soft tissues near the tragus, causing significant inflammation and pruritus.

Bilateral cases of otitis are much more common and typical of allergic disease and thus the importance of clinical recognition is most helpful when looking for primary causes for these disorders. Autoimmune skin disease can also contribute to the development of otitis, however the pinnae is almost exclusively involved. Upon otic examination, the ear canals of patients with diseases belonging to the pemphigus complex or lupus classification are usually normal.

Are there any symptoms to support an underlying disease process?

A complete and thorough history is essential in order to identify any potential underlying disease process as a cause for otitis, especially recurrent cases. Getting this information takes time, however, thus focusing on a few key questions will allow the clinician to get good information without having to ask a myriad of questions. More challenging cases will, of course, require more extensive history taking. Essentially we are attempting to determine whether an underlying disease process exists, and if so, is the patient suffering from an allergic disorder or an endocrinopathy? In doing so, the most important questions to ask are:
     • Is the patient pruritic anywhere else—face, feet, perineum?
          o If so, the clinician must treat and resolve any secondary infections.
     • When secondary infections have been treated and resolved (including the yeast or bacterial otitis), is the patient still pruritic?
          o If so, consider allergic disorders.
          o If not, consider endocrinopathies.
          o If the patient is pruritic, are the symptoms seasonal or non-seasonal?
               • If seasonal, consider atopic dermatitis.
               • If non-seasonal consider adverse reaction to food or non-seasonal atopic dermatitis
     • Age of onset:
          o Less than 1 year of age with non-seasonal pruritus = rule out cutaneous adverse reaction to food.
          o Older patient with non-seasonal pruritus = rule out cutaneous adverse reaction to food (don't forget about neoplasia in elderly patients!).
          o Between 1-3 years of age (up to age 6) = if symptoms are seasonal, consider atopic dermatitis. If non-seasonal, rule out cutaneous adverse reaction to food.
     • Do the symptoms completely resolve with steroid administration?
          o If so, consider atopic dermatitis.
          o If not, consider cutaneous adverse reaction to food, especially if the symptoms are non-seasonal in nature. **Don't forget to treat and resolve secondary infections....