Suggest Treatment For Skin Allergy

Dear Doctor, am not a CGHS Card holder however i would like to have a benefit of experts available on this site. My sister was using sisomycin sulfate cream for some skin allerges or contact dermetities occuring only on the open areas like feet and palm. now this cream in not available in market due to some gov. regulations. what is the best alternative for the same and which diagnostics test should be done to get hold on these rashes.