Final answer:
To prevent recurrent external otitis, a nurse should instruct the adolescent client to avoid getting water in the ears while swimming and perhaps use earplugs before showering. Inserting cotton swabs should be avoided, and specific ear drops may be prescribed to treat the infection.
Step-by-step explanation:
The appropriate instruction for a nurse to include when teaching an adolescent client with recurrent external otitis would be: "Avoid getting water in your ears during swimming." This is because otitis externa, or swimmer's ear, is often caused by Pseudomonas aeruginosa, a bacterium that thrives in wet environments.
Preventing water from entering the ears can help reduce the risk of infection and inflammation associated with this condition. It is important to avoid using cotton swabs which can push debris further into the ear canal, potentially causing more harm.
Furthermore, ear drops containing acetic acid, antibacterials, or steroids may be recommended for treatment to reduce inflammation and treat infection. Inserting earplugs before taking a shower can also be beneficial to protect the ear canal from getting wet.