RxContin
Greenlighter
My friend recently started injecting morphine. I know, he's heard it a thousand times, "NEVER start injecting". Please, stall us out. Anyway, this morning he woke up with these itchy pink bumps all over his legs and part of his arms. At first he was freaking out, had no idea what it was, thought he didn't filter well enough (he filters 3 times, twice through different coffee filters and once through a cotton. when finished it's clear as water), and thought he was going to die. After researching a little... nope. Just hives, which went away completely after 10 hours. 
What I'm getting at here is 2 questions.
How come this reaction only happened when he injected a small dose, and never when he ate a large dose?
Is there any way to prevent it?

What I'm getting at here is 2 questions.
How come this reaction only happened when he injected a small dose, and never when he ate a large dose?
Is there any way to prevent it?