Sorry about your reaction to the blood worms. Freeze-dried blood worms bear the "do not touch" warning but it's in such tiny print as to make the warning virtually useless. I just shake a small amount from the container into the food bowl and make sure that, if there are any left over when I clean out the bowl, that I use a paper towel rather than my finger to wipe out the contents before washing. No other freeze-dried item should trigger an allergy attack but, if you're very sensitive, just use a small plastic spoon or reptile feeding tongs to take out mealworms, crickets, shrimp, etc. And blood worms are
not necessary in a hermit crab's diet so don't worry about that.
Your crab will be fine with freeze-dried shrimp and can actually eat most things we do (without seasonings or sauces, of course). Read the Safe/Unsafe Food lists in the FAQS/Care Guides section and you'll be amazed how easy it is to keep a crab healthy with items from your pantry and 'fridge! A quick and easy source of both protein and calcium is to give the crab a half eggshell with raw albumin, basically whatever is left in eggshell after you dump the yolk and white into the pan.
And welcome aboard! Feel free to ask questions as we've all been newbies at some point

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