How Would You Treat This Axillary Rash?

Upon his return from a summer visit to North Carolina, a 53-year-old man noticed a rash confined to the left axilla. During his trip, he had participated in a variety of water sports and spent some time in a hot tub.

 Which of the following do you suspect?

A.  Contact dermatitis to a new deodorant.
B.  Staphylococcal folliculitis.
C.  Streptococcal folliculitis.
D. Pseudomonas folliculitis.
E.  Candidiasis.

(Answer on next page.)

Answer: D. Pseudomonas folliculitis

Initially, the appearance and intertriginous location of the unilateral rash suggested staphylococcal folliculitis. Contact dermatitis to deodorant would likely be bilateral; candidiasis typically features satellite lesions; and Pseudomonas  usually affects the trunk.

Oral cephalexin was prescribed. When the folliculitis did not improve after 1 week of treatment, a bacterial culture was performed; Pseudomonas aeruginosa, D, was identified. An oral fluoroquinolone was used, and the rash resolved completely.