For men, the recommended treatment is indeed the over-the-counter Canestin 1% with an application 1 to 2 times a day for 7 days. The cream is applied after cleaning and drying the penis well.
Common symptoms in men with balanitis (Candidas Albicans fungal infection) are a red or patchy rash with or without discharges of thick whitish secretions. Some will also experience discomfort or itching. So its symptoms seem to be similar.
In more severe cases, taking an oral antifungal may be required. If the 7-day treatment is not enough, your spouse will need to see a doctor to make sure it is a fungal infection and get a prescription. However, I would suggest that you seek medical attention sooner if your spouse has diabetes or is on immune-lowering medications.
Finally, I'd like to mention that some of the over-the-counter antifungal creams are petroleum jelly or oil based, so they can decrease the effectiveness of the condom and cause it to break.
Hopefully this information will be helpful to you, please feel free to write me again if needed,
Andrée-Ann Parent, pharmacy student under the supervision of Alexandre Chagnon, pharmacist