Hello Thanks for query . Pink coloured patch on the glans penis developing slowly over a period of couple of months is most likely to be what is called as Ballanitis Xerotica Obliterance (BXO). It is variant of Lichen Sclerosis and is progressive disease gradually involves foreskin resulting into Phimosis and urethra causing narrowing of urethra and difficulty in urination. Please consult qualified urologist for clinical examination to confirm the diagnosis . Unfortunately there are no medicine that can successfully treat this disease however you can slow down the progress of the disease by using topical steroid cream. Dr.Patil.