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. The phenotype is HP_0200037 (Skin vesicle).