Exodus 9:10

And they took the soot of the smelting furnace, and they stood before Pharaoh, and Moses sprinkled it toward the heavens, and it became skin sores sprouting blisters on humans and on animals.

Deuteronomy 28:27

"Yahweh shall afflict you with the boils of Egypt and with tumors and with the scurvy and with {the skin rash that cannot be healed}.

Treasury of Scripture Knowledge

Summary

And they took ashes of the furnace, and stood before Pharaoh; and Moses sprinkled it up toward heaven; and it became a boil breaking forth with blains upon man, and upon beast.

Bible References

A boil

Deuteronomy 28:27
"Yahweh shall afflict you with the boils of Egypt and with tumors and with the scurvy and with {the skin rash that cannot be healed}.