Flat circumscribed area, change in the color of skin, <1cm
-ex: freckles, petechiae, measles, birthmark
a circumscribed, solid elevation of skin with no visible fluid, varying in size from a pinhead to 1 cm
Elevated, circumscribed, superficial filled with serous fluid < 1cm e.g. varicella, herpes zoster, blister, bleb
Elevated, superficial vesicle but filled with purulent fluid e.g. impetigo, acne, furuncles, carnbuncles
A circumscribed collection of fluid more than 1 cm (big blister). Can be filled with clear, serous hemorrhagic, or purulent fluid. May hurt or itch. Poison ivy (bullous dermatitis). Some form deeper layers so less likely to rupture. Superficial ones are more likely to rupture.