Hi, I Am 40 Years Old, Female. On My Right

Hi, I am 40 years old, female. On my right arm flexor surface I developed a pink - brownish patch (similar to bruise) irregular shape that is increasing in size over last 2 years. It get more brown during sun exposure. Now it is about 10 cm. It is itchy, with few papules, no scaling. Would you advise please, what kind of ointment should I use? Thank you! I tried anti-inflammatory, it didn't help.