Dr. I am baffed by skin & RAST test!

Hi, I come today regarding a possible food allergy - to a food I love - shrimp!

For as long as I remember (I am 45 years old now), I have never been able to peel shrimp without my hands itching and turning red. If the tail or something would ***** me, I developed a raised welt (like a bee sting). I still would eat them.. and I seem to always get a mild itching in the back of my throat... but although I was concerned, it never progressed to anything more.

However, a couple of months ago, while I was eating coconut shrimp (purchased frozen at grocery store) my throat really started to itch back, and my lips and nose was tingling and I developed a large lump in my throat. (symptoms lasted several hours). It scared me enough that I didn't eat anymore from that package, but I have since ate 2 shrimp without symptoms.

I felt I should go and be checked so I went to an allergy center and had a skin test - that came back negative. I was really surprised by this, and went home, pricked my hand and rubbed the tail of the shrimp on it and sure enough - developed a welt! The allergist sent me for a RAST test - and they called yesterday with the results - NEGATIVE!!?? They said it most likely isn't a food allergy, but to avoid shrimp. This makes no sense! I don't want to avoid shrimp, and theses test are negative - so I am just baffled. Why would my self test show a skin reaction, but theirs does not, and the RAST test is also negative?

[tinkerbell622]

Thank you for your response, which has given much more information then my physician. Actually, the doctor didn't even pass the information on, it was a person from the office that called and told me that the RAST test was negative, and that it most likely wasn't a food allergy...? I truthfully am a little afraid to eat it again, and they did give me a prescription for an epie pen (which I have). The immunoglobulin G, is this just much more rare, and not tested for? If that was it, is that a food allergy  or not? They did tell me to avoid eating shrimp, but I am missing it!

[tinkerbell622]

another thing.. the skin test is really confusing because that came back negative, yet I have never been able to peel shrimp without a skin reaction.