Final answer:
After being diagnosed with otitis externa (swimmer's ear), patients should avoid swimming for at least 7 to 10 days or until a healthcare professional advises otherwise.
Step-by-step explanation:
Otitis externa, commonly known as swimmer's ear, is an infection of the external ear canal typically caused by the bacterium Pseudomonas aeruginosa. After being diagnosed and starting treatment for otitis externa, it is generally recommended to avoid swimming to prevent further irritation or the risk of exacerbating the infection. The duration of avoidance can vary depending on the severity of the infection and the treatment regimen, but patients are often advised to stay out of water for at least 7 to 10 days after the onset of symptoms or until clear guidance is received from a healthcare professional.