Allergy Testing

Has anyone ever had allergy testing on your little one !! My daughters doctor refereed us to an allergist for both my girls!

My oldest was tested when she was one because she had an allergic reaction where her face mouth & tongue swelled up (I was terrified & never drove so fast in my life to get her to the hospital she’s 10 now) it was a blood draw which showed that she was allergic to nuts, peanut butter, corn, peas & tomatoes but I was recently told that the blood test are not accurate!

She wants my now 6 month old (she will be 8 months at the time of testing) to be tested because she has really bad eczema & family history as well as my oldest be retest !

My question is what can I expect ?

Will it be painful for my girls ?