Poxclin, Virasoothe, Thuja ointment, pure aloe vera gel, calendula cream, Eurax and Aveeno stuff all very soothing for chicken pox.
Benadryl/piriton/medised are good for reducing itching.
Also oats in an old pair of tights or tied in a muslin, two large handfuls of bicarbonate of soda swirled around and a few drops of eucalyptus essential oil, tea tree essential oil, peppermint essential oil and lavendar essential oil in a luke warm bath twice a day. Chamomile tea bags in the bath are good too.