Talk to Dermatologist on Skin Issue

Hello Team,

I have noticed some changes in mole located on my arm. Actually, what I think is it was not mole at all from the very start. I remember, its just popped up out of nowhere, and there are three mole like this. 02 in one arm and 01 is on the other.

It seems different, if I pay attention, it seems the area around it is not clear, its brownish and irregular. Do you think its early warning sign? I have attached image of it as well. Need opinion.

From few years, my weight is irregular and BMI is not normal. First back in 17-18 Years my weight was good, around 55kg, but it suddenly drops from 55kg to 39 kg and now, its around 44/45kg. I occasionally get blisters in mouth and often have body ache early morning.