>My daughter reacted to milk (actually, a tiny amount of formula) by
>getting a rash.

My son reacted to milk with a rash. He also reacted to milk on his skin
with a bump. We were able to test him originally (first line- testing) by
rubbing some milk, yogurt, or sherbet on his upper arm. Wait 5 min to an
hour (may need to circle the area with marker). If get bump, he probably
still has problems. If not, he will need further testing. Many docs won't
test kids under 2 yrs, since their immune system is still developing. If
you home test, try milkmixed with potatoes or hidden in something. You may
need to do this for 3 days in a row for symptoms to start showing up.