How Can Recurrent Penis Spots With Itching And Redness Be Treated?

I am male 30 from newyork. before 3 months I fell sick with high fever. My doctor gave me antibiotics which were 1000mg. Those reduced my fever but I got reg itchy spots on my penis. I consulted a dermatologist, he told this is because of immune loss due to high dosage of antibiotic, and gave me CANESTAIN ( citrimazol 10%) cream to apply and 10 days B+ vitamin tablets. All itch and red spots gone. But they returned after a month.I applied the cream, they went off completely. But It has come back yesterday. I am worried now. Please help