Just got back last sunday....JBR is on the way...and quite a few people we met there have reacted to Henna tatoos!! Both of my children & myself & my husband have had them done & have not reacted, but I found this info on the web. Check it out...I dont think I want another one & hope that we still dont get some kind of delayed reaction!!
http://www.expat.or.id/medical/blackhennareactions.html