Are the oils in a mango's skin toxic?

You can be allergic to mango skins. But that doesn't mean they're toxins, except for the person who is allergic to them. So I guess "toxin" is a relative term.

Mangoes are indeed related to poison ivy, as well as sumac. They are all members of the Anacardiaceae family.

Mangoes are the world's #1 consumed food?
How bout rice? corn?
Bizarre.

I once lived on a mango farm, and they told us that it was the sap that could cause allergic reactions, not the skin of the mango. So wash your mango carefully to remove the sap and then you can handle it without worries...

Yes, the sap that contains it resides mainly in the skin. In Hawaii, when I was about 13, our local family friends told us to wash the skin around our mouths after eating one. Especially if you eat it like a pig, which I did, scrapping all the meat off the skin with my mouth. Naturally, as a teen rebel, I deliberatly didn't wash my face and developed a huge hideous rash around my mouth which looked and felt like a huuuuuge cold cold sore. It itched, bled, and oozed for weeks. Horrible experience. Learned my lesson haha

I think it is not the oil, maybe you are referring to sap. In some cases it caused rash to some kids.