Richtlijn: Otitis Externa - Kwaliteitskoepel

Therapieresistentie
Uitgangsvraag 7
Wat is de aanbevolen strategie bij therapieresistente OE?
Onderbouwing
Definitie
In this guidelines three fases of otitis externa are distinguished; (1) acute otitis externa, (2)
persistent and (3) chronic otitis externa. In this section treatment of persistent OE is discussed,
in section 8 treatment of chronic OE is addressed.
Acute otitis externa was defined as redness or swelling of the external auditory canal or debris
within the canal, accompanied by pain, itchiness, otorrhoea, often accompanied by hearing loss,
or aural fullness, for less than three weeks. After three weeks of persisting symptoms it is called
persistent/therapy resistent otitis externa. After three months we speak of chronic otitis
externa.
Causes of treatment failure
If the clinical symptoms fail to respond to therapy a reassessment of the probable cause of the
external otitis should be made. Reinspection; otoscopy and thorough cleaning of the ear canal is
necessary. Also a culture of debris in the ear canal should than be considered.
There are several causes of treatment failure:
Obstructed ear canal
If topical antimicrobial therapy was prescribed, the clinician should reassess the patency of the ear
canal to ensure that edema, debris or a corpus alienum are not impeding drug delivery. Any
obstruction should be addressed with aural toilet, wick placement, or both (see preceding section,
question 6), or, if the obstruction cannot be relieved, systemic therapy is begun with an oral
antibiotic that covers P aeruginosa and S aureus.
Poor adherence to therapy
Assessment of adherence with therapy is important (compliance).
Alternative causes of ear pain and associated otorrhea should be considered if the patient fails to
respond to treatment (Rowlands, 2001).
Misdiagnosis
In section 1a the differential diagnosis of acute otitis externa is presented. If acute otitis externa
persists, this differential diagnosis should be reassessed (question 1a) and modifying factors should
be reconsidered (question 1b). Several other causes of misdiagnosis can be present (question 7). An
overview is presented in Table 2. Persistent symptoms can be caused by dermatologic disorders that
include seborrheic dermatitis, psoriasis, dermatomycosis, folliculitis or acne that involves the
33 Richtlijn Otitis Externa 2010
Nederlandse Vereniging voor Keel-Neus-Oorheelkunde en Heelkunde van het Hoofd-Halsgebied