73.1 Ear Infections

(See also chapters in Section I)

73.1.1 Otitis Externa

• Acute infection

This is an inflammation of the ear canal, commonly caused by bacterial infection

Symptoms can include itchiness, discharge, and pain

Common bacterial causes: Staphylococcus aureus (yellow crusted discharge), Streptococcus pyogenes are the most common pathogens

Treatment should be with ear drops if mild or systemic in severe cases

• Chronic (swimmer’s ear) infection

Ongoing mild infection—may be due to underlying seborrhoeic dermatitis or frequent swimming or diving leaving the ear canal wet

Typical pathogens are Pseudomonas species (they are water loving), S. aureus, Enterobacteriaceae, and Aspergillus species

Treatment includes aural toilet by ENT specialist and ear drops (e.g., ofloxacin 0.3% or polymyxin B + neomycin + hydrocortisone)

If S. aureus and associated pinna cellulitis, systemic treatment with antistaphylococcal agent (e.g., floxacillin) may be appropriate

• Malignant/necrotizing infection

This is a very severe form of acute otitis externa

It presents acutely with a systemic inflammatory response and fever

High-risk groups are patients with diabetes, AIDS, and those on chemotherapy; usually seen in elderly patients

The infection is mainly bacterial and includes Pseudomonas aeruginosa (90%) and S. aureus

Bony involvement is not uncommon

Ear swab and tissue should be cultured for pathogens prior to antibiotic treatment

Treatment must be initiated rapidly and includes systemic antibiotics with antipseudomonal activity, e.g., meropenem, ceftazidime, tazobactam, gentamicin, or ciprofloxacin

In osteomyelitis treatment should be for 4 to 6 weeks (CT or MRI may aid diagnosis); monitoring of inflammatory markers (e.g., C-reactive protein) can help indicate response to treatment

73.1.2 Otitis Media

• Acute infection

This is an infection of the middle ear caused by viruses and/or bacteria (S. pneumoniae, Haemophilus influenzae, occasionally Moraxella catarrhalis)

Tympanic membrane may be perforated with purulent yellow mucus and pain