Mold like that doesn’t form unless there are two factors involved: dampness and something for it to feed on. When it comes to a moldy wall, the “food” is usually the glue used to adhere wall paper/vinyl. Notice how there is no mold on the wall where it is painted, yet there is where the baseboard has been removed? Somehow, moisture was trapped between the wood and the wall.
Since the mold seems to be contained to a small area, it’s worth attempting to handle on your own vs. calling in professionals. However, it’s important to not take any risks that can involve a human or pet’s health. Mold spores are not something to deal with lightly.
Here is a link to Removing Mold from Walls/Baseboards. @Dutchess_III, if you are the one tasked with addressing this, I hope that you follow the instructions. Your health, especially after recently suffering from breathing problems, isn’t worth the risk.
And I’m sorry @Seek for having to disagree with you on this; spraying the wall is a risk factor. Wiping it down first will prevent mold spores from becoming airborne.