Was nervous after makeup artist touched my face directly and applied purell to chin and cheeks but now i see one shouldn't do that - what should i do now to try to prevent skin damage like moisturize? if only did once is it likely to cause harm?

It would be helpful to apply a moisturizer since the biggest risk to using this on your face is dryness. This is likely the only thing that is needed since it only happened once. If you develop any other symptoms besides dryness, then you can see your doctor but applying a moisturizer and keeping the skin from becoming too dry will likely prevent any other issues. Good luck!