Increasing redness that spreads beyond the pimple
Significant swelling or warmth around the area
Severe or worsening pain
Pus that is thick, yellow, green, or foul-smelling
A hard, tender lump that keeps growing
Crusting with increasing redness or oozing
Red streaks extending from the pimple
Fever or chills
Swollen lymph nodes
The pimple not improving after several days or getting worse quickly