Raised scabs on succulent leaves

[kestrel]

Raised, beige scabs at the base of echeveria purpusorum leaves and possibly on the stem. The scabs are silvery, with little black dots and some are slightly cracked. The bottom leaves are more affected, and I don't see any bugs. The plant doesn't seem too affected but I still worry.

I've been bottom watering it to avoid water getting between the leaves, and it's in a spot with air circulation, but the leaves are very close to each other. None of the succulents under the same lamp seem to be affected. The top leaves don't have any scab either (that I can see).

Help?