Greenish-blue staining of underclothing due to Pseudomonas aeruginosa infection of intertriginous dermatitis.

Intertrigo (intertriginous dermatitis) is an inflammatory condition of the skin folds, induced or aggravated by heat, moisture, maceration, friction, and lack of air circulation. Intertrigo can become secondarily infected. Three cases of intertrigo are described herein which presented with greenish-blue staining of underclothing. Cultures revealed Pseudomonas aeruginosa which is a gram-negative aerobic bacillus that produces the pigments pyocyanin and pyoverdin that responsible for this characteristic hue. All three patients responded to a course of oral ciprofloxacin with resolution of the intertriginous dermatitis. Therefore, greenish-blue staining of clothing is an important indicator for pseudomonal intertrigo.