Primary Lesions -macule -patch -papule -plaque -nodule -tumor -vesicle -bulla -pustule -cyst Secondary Lesions -scale -crust -excoriation -lichenification -maceration -fissure -erosion -ulcer Distinct Lesions -wheal/hive -burrow -comedone -atrophy -keloid -fibrosis -petechiae -telangiectasis -milium
Crust is dried exudate (ie. blood, serum, pus) on the skin surface