child 5 yrs irritable and itchy

5 yr old child, male. one brother 9 , sister 1. irritable and unruly during play and generally at home. disciplined and good at school. difficult first yr last year. craved for friends and acceptance, but did not have initiative. better adjusted this yr as more friends. relationship with sister loving. most interaction with brother, but also a rivalry there. hits him a lot, while brother does not hit back. but there is periodic teasing from brother. also a lot of yelling and breaking of rules, does not immidiately follow instruction from father or mother. sometimes responds well to loving entreaties, but has to be shown fear of punishment many times. understands when explained to, but ignores later.
dry skin has been a constant problem from birth, various lotions and ointments have been tried. most frequently aveeno. given a dose of bryonia 30 a couple months ago, treated itch for the time being but is now coming back.
eating has been a problem too, breakfast - eats nothing before school, only a cup of milk after many antreaties. brings back the lunch pale home sometimes untouched, very hungry and irritable when gets hime at 3 pm.