Otitis Externa

Question 1

What is Otitis Externa?

Answer 1

• This is the inflammation of the skin in the external ear canal

Question 2

What determines the difference between acute otitis externa and chronic otitis externa?

Answer 2

• Acute <3 weeks
• Chronic >3 weeks

Question 3

What is another name for Otitis Externa?

Answer 3

• Swimmer’s Ear

Question 4

What are predisposing factors for Otitis Externa?

Answer 4

• Exposure to water
• Trauma in the ear canal

Question 5

What is protective against Otitis Externa?

Answer 5

• Ear Wax

Question 6

What are some of the causes of Otitis Externa?

Answer 6

• Bacterial Infection
• Fungal Infection (aspergillus/ candida) - multiple courses of topical antibiotics. Antibiotics kill off the friendly bacteria which have a protective effect against fungal infections
• Eczema
• Seborrhoeic Dermatitis
• Contact Dermatitis

Question 7

What are the bacterial causes of Otitis Externa?

Answer 7

• Pseudomonas Aeruginosa
• Staphylococcus Aureus

Question 8

What is important to know about Pseudomonas Aeruginosa ?

Answer 8

• Gram-negative aerobic rod shaped bacteria
• Can colonise the lungs in patients with cystic fibrosis
• naturally resistant to many antibiotics and can be treated with gentamicin/ ciprofloxacin

Question 9

How does Otitis Externa Present?

Answer 9

• Ear Pain
• Discharge
• Itchiness
• Conductive Hearing Loss

Question 10

What would be seen on examination for Otitis Externa?

Answer 10

• Erythema/ Swelling of the ear canal
• Tenderness of the ear canal
• Pus/ Discharge in the ear canal
• Lymphadenopathy

Question 11

How can Otitis Externa be diagnosed ?

Answer 11

• Otoscopy
• Ear Swab (to determine causative organism)

Question 12

What is the managment of mild Otitis Externa?

Answer 12

• Acetic Acid 2% (anti fungal and antibacterial effect)
• can be used prophylactically before and after swimming in patients who are prone to otitis Externa

Question 13

What is Malignant Otitis Media?

Answer 13

• This is an uncommon type of Otitis Externa that is found in immunocompromised individuals (diabetic patients)

Question 14

What is the common causative organism in Malignant Otitis Externa?

Answer 14

• Pseudomonas Aeruginosa

Question 15

What is the Pathophysiology of Malignant Otitis Externa?

Answer 15

• Infection occurs in the external auditory meatus in the soft tissue
• This progresses to involve the soft tissues into the bony ear canal
• Progresses to temporal bone osteomyelitis

Question 16

What are the key features in the history of malignant Otitis Externa?

Answer 16

• Diabetes/ Immunosuppression
• Severe/ unrelenting/ Deep-seated Otalgia
• Temporal Headaches
• Purulent Otorrhea
• Possibly dysphasia, hoarseness, or facial nerve dysfunction

Question 17

What investigations can be done for Otitis Externa?

Answer 17

• CT scan

Question 18

What is the treatment for Malignant Otitis Externa?

Answer 18

• ENT Admission
• IV Antibiotics
• Imaging ( CT/ MRI) to assess the extent of the infection

Question 19

When should there be a referral to ENT?

Answer 19

• non-resolving otitis Externa with worsening pain

Question 20

What is the treatment for moderate Otitis Externa?

Answer 20

• topical antibiotic and steroid: (neomycin, dexamethasone and acetic acid), (neomycin and betamethasone), (gentamicin and hydrocortisone), (ciprofloxacin and dexamethasone)

Question 21

What are the side effects of Aminoglycosides?

Answer 21

• Potentially Ototoxic if they are able to get past the tympanic membrane
• It is essential to exclude a perforated tympanic membrane before using topical aminoglycosides in the ear
• Refer a patient for Micro-suction of the debris from the canal to help visualise the tympanic membrane
• ## Refer the patient if the canal is so blocked/ swollen and topical treatments cannot reach the site of infection

Question 22

What is the treatment for severe Otitis Externa?

Answer 22

• oral antibiotics
• discussion for ENT admission with IV antibiotics
• Ear Wick - used in the canal when it is very swollen and treatment with ear drops or sprays may be difficult ( contains topical treatments for otitis Externa - antibiotics and steroids)
• Wicks are inserted into the ear canal and left there for a period of time
• As the swelling and inflammation settle, the ear wick can be removed and treatment can continue with drops or sprays

Question 23

What is the treatment for fungal Infection of the ear?

Answer 23

• Clotrimazole

Question 24

What are the complications of malignant otitis Externa?

Answer 24

• Facial nerve damage and palsy
• Other cranial involvement (glossopharyngeal, vagus or accessory nerves)
  -Meningitis
• Intracranial thrombosis
• Death