Used primarily to describe a medical issue; it's technical and might be seen in medical contexts. The doctor examined the pustule for signs of infection.
Pro Tip 2/3
Avoid Confusion
Do not confuse 'pustule' with 'pastel'; they sound similar but have different meanings. I mistook 'pustule' for 'pastel' and was confused about the skin condition.
Pro Tip 3/3
Discomfort Indicator
Often used to indicate discomfort or a problem area on the skin that may need treatment. He kept scratching the pustule despite the discomfort.