Growing, spreading round dark spot of dry peeling skin; painless, no itch, flat?

[Drunes]

Hello,
Just yesterday, I noticed a round spot which is a few shades darker than my skin tone. It's akin to a light bruise. This spot is dry and thin peeling but not at all itchy, no pain whatsoever and is flat. The size is about 2 cm in diameter and it's located on my right thigh above the knee.
Today, when I checked it, the spot appears to have grown more than a cm. It's oblong now and the color is at least a shade darker than it did yesterday. Worse, a dry and peeling spot has appeared on my left thigh also just above the knee. Still no pain, no thickening of skin, no itch. They're both just flat spots a bit darker than my skin with thin peeling.
I've only tried applying a moisturizing cream to it today so I've yet to see any effects.
I usually sit on the floor with crossed legs or on a chair and eitherway my elbows are resting directly on these areas where the dry spots appeared so I first thought they were regular marks left by the weight from my elbows. But when I looked closer, it's actually a dry spot.
Since the only alarming symptom for me is how it appears to be growing and spreading, I figured I could wait a bit longer until I go have it checked by a dermatologist. Looking around for answers online has yielded very little results that can relate to my condition so I thought I could give this site a try first.
I hope anyone can help. Thank you.