The infection occurs more commonly in summer months, often in association with water sports, and is commonly referred to as “swimmer’s ear.” Predisposing factors, in addition to warmth and moisture, are micro-trauma from scratching or instrumenting the ear, preexisting seborrheic dermatitis of the ear canal, and alkalization of the external canal (Coffin 1963; Fabricant and Perlestein 1949). The most commonly recovered pre-therapy isolates are Pseudomonas species (most commonly aeruginosa), and Staphylococcus aureus. Less frequently, other gram negatives, especially Proteus sp. and Klebsiella, are encountered (Hawke et al. 1984; Roland and Stroman 2002).