TEM of an erythema toxicum lesion; the biopsy was obtained from an infant with body temperature of 38.3°C and skin culture positive for CoNS at the time of the study. (a) Overview close to a hair follicle containing capillaries, single cells with morphologic features of polymorphonuclear leukocytes (P), macrophages (M), and eosinophils (E). Note the close proximity to blood vessels in the connective tissue sheath. Macrophages communicate with other cells (arrow). (b) High magnification showing activation of endothelial cell, i.e. increased numbers of pinocytotic vesicles (arrow). Bar: a = 15 μm, b = 0.5 μm.