Dark Growing brown Spots under arms

Skin, nail and hair health
1

I have these dark brown spots under my arms I don’t know what they are or what caused them, they are completely flat and do not hurt I have smaller ones appearing under my other arm

what are they and should I get checked?

thank you.

2

Looks like discoid eczema or ring worm.

3

I don’t think that’s what it is, those are mostly red, itchy and the pigmentation is not equally distributed throughout the affected area, mine don’t itch, are medium-dark brown in color and the pigmentation is equally distributed.

4

I went to dermatologist and it turned out to be Tinea Versicolor i was prescribed an anti fungal cream and shampoo and they are slowly fading away

thanks anyone who helped.