Pseudomonas dermatitis or hot-tub rash is often caused by the bacteria “Pseudomonas aeruginosa“. They are commonly found in the environment (water, soil). Most rashes clear up in a few days without medical treatment. However, if your rash persists, consult your healthcare provider. Hot-tub rash is spread by direct skin contact with contaminated water. The rash usually occurs within a few days of swimming in poorly maintained hot tubs or spas but can also be spread by swimming in a contaminated pool or lake.