Tinea cruris is caused by fungal infections, and indeed, this disease has strong contagiousness and recurrence. However, there are several reasons for its recurrence, with two common ones. The first is that the treatment was not completely effective; antifungal creams need to be applied continuously for at least one or even more than two months to completely eliminate the fungus. The second reason is re-infection after successful treatment due to not taking precautions, such as bathing in public baths, swimming, or interacting with someone with athlete's foot. Additionally, washing socks and underwear together can cause cross-infection. Therefore, during and after treatment, it is crucial to maintain attention long-term, regulate diet, and lifestyle habits to prevent recurrence of the condition.