Otitis externa

Otitis externa occurs in 4 types: 1) Acute localized (furunculosis from S. aureus); 2) Acute diffuse (swimmer's ear); 3) Chronic (drainage from a chronic middle ear infection); and 4) Malignant (painful and purulent otorrhea with granulation tissue in elderly diabetic or immunocompromised patients).

CASES/YEAR
1,200,000 (US); 24,000,000 (Global)
AGENT TYPE
Mixed
OTHER NAMES
Swimmer's ear;
ACUITY
Acute-Moderate
INCUBATION
Estimated: days to weeks;
INITIAL SYMPTOMS
Acute: ear pain; Chronic: itching; Invasive: Purulent drainage, ear pain, and swelling;
PRECAUTIONS
COMMENTS
The 4 main types are: 1.) Acute localized (furunculosis from S. aureus); 2.) Acute diffuse (swimmer's ear); 3.) Chronic (drainage from a chronic middle ear infection); and 4.) Malignant (painful and purulent otorrhea with granulation tissue in the posteroinferior wall of the canal in elderly diabetic or immunocompromised patient); [Harrisons, p. 250] Otitis externa may begin as a pustule or furuncle of a hair follicle. Malignant otitis externa is usually caused by P. aeruginosa in diabetic, elderly, or immunocompromised patients. Permanent facial paralysis is a complication. Aspergillus niger can grow in the external canal as a greenish or blackish fluffy colony. [PPID, p. 836] Osteomyelitis of the skull is a complication of malignant otitis media. [Cohen, p. 393] Fever is uncommon in cases of malignant otitis externa. Infrequent complications are meningitis and brain abscesses. [ID, p. 1708]
DIAGNOSTIC
For invasive disease: Culture, Biopsy, Head CT;
SCOPE
Global
SIGNS & SYMPTOMS
  • >fever
  • H lymphadenopathy
  • S pustule
  • *brain abscess or lesion
  • *cranial neuropathy
  • *meningitis
  • *osteomyelitis
ANTIMICROBIC

Yes

VACCINE

No

ENTRY
Skin or Mucous Membranes (Includes Conjunctiva)
RESERVOIR
RISK FACTORS
  • Cancer patients
REFERENCES FOR CASES/YEAR
1. (US) 4 per 1000; [Gorbach, p. 298] Calculate: 4 x 300,000 = 1.2 million (US); 1.2 million x 20 = 24 million (worldwide);
2. (Global) 20 X US cases/yr;