Euphorbia leuconeura

It's a Plumeria.

Floral_uk is correct. Note the ridges on the stem, not found on Plumerias.

Either has latex sap. A safe course of action would be to take precautions to avoid contact with that. Finding out accidentally you're allergic to latex is probably something most people would be happier not knowing. In this case, ignorance is truly bliss, and washing immediately doesn't seem to avoid a rash, at least on my skin. Until recently, latex did not bother me...

Plumerias don't pile up the leaves on top of each other like that, whereas this is typical for the euphorbia. And their leaves are firmer and thicker.