Incubation period is 14 days, but shorter in immunocompromised host}Mild fevers occur 10-20 days after exposure}Prodromal symptoms consisting of low fever, headache, and malaise occurring 2 to 3 days before the eruption}Eruptive phase: they appear as macules, papules, vesicles, pustules and crusts. The most characteristic lesion is a vesicle looking like a drop of water on the skin. Vesicles rupture easily and may become infected}The rash begins on the trunk and spreads to the face and extremities}Lesions of different stages (crops) exist together at the same time in any given body area}Complications may include septicaemia, pneumonia, fulminating haemorrhagic varicella, and meningoencephalitis