See below. Eurax is primarily used for persons with scabies. It has scabicidal and antipruritic/itch actions. The mechanisms of these actions are not known. For chickenpox-i recommend antihistamines that are sedating like benadryl (diphenhydramine). Topical lotions/creams like calamine or aveeno tub soaks can help. I would save the Eurax for scabies infestation-aka body lice.
No. Eurax (crotamiton) is used for a totally different condition, scabies.