Treatment of otitis externa is dependent on identifying and controlling the predisposing factors, primary and secondary causes
and perpetuating factors whenever possible. Inadequate treatment and reversal of the progressive pathologic responses, tympanic
membrane alterations, and otitis media often leads to treatment failures or recurrences. Even though externally and to the
client the ears seem better, adequate treatment can only be determined by otoscopic examination and follow up cytological
examination of material from the ear canal. The treatment of otitis externa often requires a complete plan that will involve
the use of multiple components. It is essential for these components to be successful that there is good client compliance.
In general achieving compliance is greatly facilitated when the client understands the problems and corresponding goals. It
is critical that follow up examinations are performed and clients or the clinic effectively keep the ear canal clean from
excessive build up of debris, microbes or exudates. The client must be able to properly apply topical medications or an alternative
form of therapy is required.
PSPP Systemę For Otitis Externa
Whenever a case of otitis, especially chronic otitis, presents then the PSPP System (see table 1 and
http://www.animaldermatology.com/) should be used to help establish what is really happening in the ear and educate the client.
Table 1 from PSPP Systemę
This is done by entering a list of potential components of their pets ear disease and explaining them to the owners in a visual
method, with simple drawings. The drawings help educate the owner about normal ear anatomy and physiology as well as perpetuating
factors that may occur. Each patient has their information entered into the table. Tests and treatments for each component
of the pets problem are listed and categorized prognostically, cured, requires long term management to achieve control or
will require life long treatment. This simple system greatly facilitates educating clients about their pets problem. It
gives the client reasonable expectations about the prognosis and what will be involved in "fixing" their pet. This results
in improved client compliance and minimizes client frustration and searching for a "better" veterinarian.
Why Clean Ears
Thorough cleaning of the ear canals is extremely important for the effective management of otitis externa. It is often the
most important step and if one treatment only was allowed to manage ear cases the it would definitely be cleaning as not single
topical product is as effective. Different types of debris may occur in ears and there presence can impact otitis and the
response to therapy. In normal ears little debris is present and it is composed of keratinocytes, cerumen and some microorganisms.
In otitis cases there are multiple reasons why it is important to clean out excessive or abnormal debris. The debris can
hinder the penetration of topical agents to the affected tissue requiring treatment, and large deposits may prevent medication
from reaching the deeper parts of the horizontal canal, tympanum or middle ear when the tympanum has been compromised. This
leads to the number one rule of topical therapy, the ingredient must reach the site to be treated. The debris can protect
microbes that are rolled in or attached to keratinocytes and covered with a protective lipid layer. These organisms may survive
therapy and then infect the ear again. Larger clumps of debris may remain in folds, middle ears and false middle ear cavities
where they sequester organisms. Retained debris may also contain pro inflammatory material such as microbial byproducts and
toxins as well as mediators released from inflammatory cells that may be present. Purulent exudates interfere with and bind
to antibiotics such as polymyxin and aminoglycosides. Complete otoscopic examination with visualization of canal and tympanum
pathology will often require cleaning. In some cases the use of a stronger topical agent or overuse of antibiotics can be
prevented by regular intervals of ear cleaning, especially if disinfectants are included in the cleaning process. When progressive
pathologic changes result in abnormal epithelial migration or folding in the canal lumen then cleaning will be required until
this normal physiologic function returns.
Cleaning of the ear canals is extremely important for the effective management of chronic otitis externa. Cleaning the ear
canal is a lot like cleaning a skin fold lesion. With chronicity the lining of the ear canal is thrown into proliferative
folds. Management of fold dermatitis requires surgical removal or keeping the skin folds clean. Without surgery successful
control often requires keeping the skin folds clean indefinitely or until the ear canal normalizes and the folds are resolved.
In chronic cases with otitis media this also includes cleaning the bulla or false middle ear.