Otitis externa

Case Definition:

Inflammation of the skin of the external auditory meatus. Acute severe otitis externa may be caused by Stapholococcus aureus or Beta-haemolytic Streptococci.

Malignant Otitis Externa is defined as an uncommon but potentially fatal and aggressive infection of the external ear canal. If left untreated it can lead to cartilage and bone involvement with adjacent cranial nerve involvements. Can be seen in diabetics and in immunocompromised patients. It is often caused by Pseudomonas aeruginosa but can be associated with a fungal infection.

 

Diagnostic criteria:

Otalgia, otorrhea and deafness. The skin of the external auditory meatus is oedematous and inflamed. The ear canal may be blocked with discharge. In fungal infections hyphae can be seen microscopically.  

Specimens to be collected:

  • Ear swab for bacterial culture

 

Notes:

Antibiotics are not usually indicated for otitis externa unless it is malignant otitis externa. Usually aural toilet and/or topical drops are all that is required and antibiotics do not confer a better outcome.

For acute severe Otitis Externa, treatment should be according to ear-swab results if topical antibiotics fail. Systemic antibiotics should be given if there is cellulitis or disease extending outside the ear canal.

Malignant Otitis Externa needs prompt systemic treatment with ciprofloxacin (po or iv) and sometimes with other intravenous antibiotics depending on sensitivity. Additionally topical treatment with either Ciprofloxacin or Gentisone HC ear drops. Patients must be referred to ENT.

Care with the use of prolonged topical aminoglycoside drops especially with a perforation. Risk of ototoxicity and vestibulotoxicity. Discuss with ENT Consultant, each case may need individual tailored treatment  and refer to guidelines issues by ENT-UK.
ENT-UK guidance states:
1. Topical aminoglycosides should only be used in the presence of obvious infection
2. Topical aminoglycosides should be used for no longer than 2 weeks
3. The justification for using topical aminoglycosides should be explained to the patient
4. Baseline audiometry should be performed, if possible or practical, before treatment with topical aminoglycoside
5. Risk of antibiotic resistance with long term use of Ciprofloxacin ear drops

 Otitis Externa - see table 2 below for necrotising or malignant otitis externa

Table 1

Severity
(classification)

1st line oral/iv antibiotics

Penicillin allergy
(see explanatory notes)

A

(bacterial)

General otitis externa

  • For mild infection or inflammation:

Acetic acid 2% spray: 1 spray tds for 7 days 

 

  • For suspected bacterial infection and eczematous inflammation:

Otomize® (Neomycin sulphate with Corticosteroid): 3 drops tds for 7 days

 

OR

Sofradex® (Framycetin and Gramicidin with Corticosteroid): 3 drops bd – tds for 7 days

***NOTE: Sofradex classed as less appropriate for prescribing in BNF***

 

  • If there is a stable eardrum perforation use:

Ciprofloxacin ear drops: 3 drops tds for 7-14 days

NB: Use eye drop solution as ear drops. Unlicensed indication but BNF recommended.

Not Applicable
B/C

Acute severe otitis externa with / without facial cellulitis (Staphylococcus aureus or Beta-haemolytic Streptococci)

 Review doses in renal impairment

 BENZYLPENICILLIN 2.4g iv qds

Plus

FLUCLOXACILLIN 1g iv qds

If current/previous MRSA positive:

Add

TEICOPLANIN iv every 12 hours for 4 doses then once daily.

Dose

<50kg: 400mg

50-100kg: 600mg

>100kg: 800mg 

Maintain treatment pending pre-dose (trough) level on Day 5. Target level 15-60mg/L.

 Typical total course length: 7-14 days

  • Fungal otitis externa - if Candida or Aspergillus species grown use:

CLOTRIMAZOLE 1% solution applied 2-3 times daily  . Treatment should be continued for at least two weeks after clincal resolution.

  • For suspected severe invasive fungal infection discuss with microbiology.

 CLINDAMYCIN 1.2g iv qds

If current/previous MRSA positive:

Add

TEICOPLANIN iv every 12 hours for 4 doses then once daily.

Dose

<50kg: 400mg

50-100kg: 600mg

>100kg: 800mg 

Maintain treatment pending pre-dose (trough) level on Day 5. Target level 15-60mg/L.

 

 

 Typical total course length: 7-14 days
 

  • Fungal otitis externa - if Candida or Aspergillus species grown use:

CLOTRIMAZOLE 1% solution applied 2-3 times daily  . Treatment should be continued for at least two weeks after clincal resolution.

  • For suspected severe invasive fungal infection discuss with microbiology.

IV to Oral Switch (explanatory notes

Only when there is clear improvement

FLUCLOXACILLIN 1g po qds
plus
AMOXICILLIN 500mg po tds

 

 If current/previous MRSA, add:

DOXYCYCLINE 200mg po od

Typical total course length: 7-14 days

CLINDAMYCIN 450mg po qds
STOP and review if patient develops diarrhoea

 If current/previous MRSA, add:

  DOXYCYCLINE 200mg po od

Typical total course length: 7-14 days  

Necrotising or malignant otitis externa

Table 2  

Severity
(classification)

1st line oral/iv antibiotics

Penicillin allergy
(see explanatory notes)

A/B/C

Necrotising or malignant otitis externa

Review doses in renal impairment

Gentisone® HC: 3 drops tds for 7-14 days
Plus
Systemic antibiotics

 

  • If there is a stable eardrum perforation use:

Ciprofloxacin ear drops: 3 drops tds for 7-14 days 
NB
: Use eye drop solution as ear drops. Unlicensed indication but BNF recommended.
Plus
Systemic antibiotics (see below)



Systemic antibiotics:

  • <65 years old
  • 

CEFTAZIDIME 2g iv tds
Plus
GENTAMICIN iv (as per local protocol

 

  • >65 years old

TAZOCIN 4.5g iv tds
Plus
GENTAMICIN iv (as per local protocol

If severe fungal infection suspected, discuss with microbiologist.

Typical total duration : 4-6 weeks

 Discuss with Microbiologist

 

 

 

 

 

 

 

 

 

 

 

 

 

 


If severe fungal infection suspected, discuss with microbiologist.

Typical total duration : 4-6 weeks

IV to Oral Switch (explanatory notes)

 
CIPROFLOXACIN 750mg po bd

Typical total duration : 4-6 weeks

CIPROFLOXACIN 750mg po bd

Typical total duration : 4-6 weeks

Last reviewed: 23/04/14

For guidance on the administration of intravenous antibiotics
click here (GHNHSFT intranet only)