I got a manicure this weekend and this lady had a massive wart on her thumb. she also gave me an arm massage! i saw it too late. what do i do?

Do nothing: First, maybe it wasn't a wart. Other skin conditions can cause similar appearance. If it was a wart, probably you are not at risk. Most hand warts are caused by HPV type 1, and the large majority of us probaby are exposed and infected with HPV1 during childhood. If so, you are immune and won't catch it again. See doctor for any skin bumps in the areas touched. Otherwise no worries.