Abnormal blistering of the skin Localized skin lesion Skin vesicle 2010-06-18T01:58:15Z UMLS:C3814530 Vesicles should be distinguished from bullae, which are are blisters that are greater than one cm in diameter containing serous or seropurulent fluid. Puss-filled vesicles are termed pustules. A circumscribed, fluid-containing, epidermal elevation less than 10mm in diameter at the widest point that (i) Contain serous exudates or serum mixed with blood or pus; (ii) Are discrete, grouped, irregularly distributed, or linear as in Rhus dermatitis; (iii) Are short-lived. Vesicles may break spontaneously or evolve into bullae by enlarging or coalescing with other vesicles. HP:0200037