Rash of chikenpox can be differentiated from the rash of small pox

<p> small pox:- Characteristics of rash:- Deep seated Vesicles multilocular Only one stage of rash seen at one time. No area of inflammation around vesicle. Evolution of rash-slow,passing through definite stages of macule,papule,vesicle and pustule. Scab begins to form 10-14 days after the rash appears. CHICKEN POX:- Distribution of rash:- Centripetal Axilla affected Rash seen mostly over flexor aspect. Characteristics of rash:- Superficial Unilocular-dew drops like appearance. Rash pleomorphic- different stages of rash evident at one time. An area of inflammation seen around vesicle. Evolution of rash : very rapid. Scab begins to form 4-7 days after the rash appears. {Reference: park&;s textbook of preventive and social medicine, 23rd edition, pg no.145}</p>