Vitiligo or something else?

Nicole • Mother, wife, surgical assistant. I have the unpopular opinion.

My 16-month-old has some sort of discoloration on her legs. My husband and I agree that it looks like little patches of lighter skin, while my mom thinks it looks like the majority of her leg is darker and that the patches are her actual skin tone. (Unfortunately I don't have a photo, as it doesn't show well in any pictures I have.)

I noticed this over the weekend; at first it was really only noticable in certain lighting. I freaked out because it looked like scars to me, but she's had no injuries, no scrapes or anything. I assumed it would go away but it's still there so I've made an appointment for tomorrow.

My initial thought after seeing it in the sunlight today was vitiligo, but upon doing some research, I see that it most commonly appears on extremities or on the face; hers is on her legs. My mom, who thinks the darker, larger areas of her legs are the issue, believes she's retaining water, but there's no pitting and her legs look their normal size to me (although she has always has a thick foot; can't hardly fit any shoes on this kid).

Has anyone else had an experience with anything like this? I'm sure I'll get an answer tomorrow but until then it'd be nice to hear from peers.