How can someone have allergic reactions to shellfish sometimes, but not all the time?
April 24th, 2010 | 
Author: I’ve had three bad reactions to shellfish:
1st – age 17 Lobster from San Fransisco made my tongue feel like needles/chemical burn, then serious heartburn acid reflux effect, and slightly restricted breathing w/fast heartbeat.
2nd – age 25 Sushi from a Japanise restaurant in Las Vegas gave the same effect.
3rd – age 26 Lobster in Kuwait gave the same effect.
I accidentally took medicine today containing 300mg of iodine but no effect, so it’s not the iodine I’m allergic to. Could it be something that is sometimes used to cook shellfish?
Maybe it has to do with the amount they ate at a certain time?
maybe it wasnt the shellfish, but an ingredient that some places use and some dont
Must be in the quantity. Once I ate too much shrimp and got itchy. Never happened to me before.
Its not the iodine that causes shellfish allergies,Iodine allergy is different.It is possible not to react every time you consume shellfish,because you can get what is called delayed food allergy symptoms.But its extremely risky for you with the symptoms you described to be eating any shellfish at all.You can have a serious reaction called an anaphlactic shock and it is life threatening,see an allergist and always carry benadryl or epi-pen avoid seafood restaruants as well !
you suffer from a shellfish allergy, strictly avoiding shellfish and food containing shellfish is the only way to prevent a reaction. If your doctor is able to identify exactly which type of shellfish causes your allergies, than you only need to eliminate that type of shellfish from your diet. For the majority of shellfish allergy sufferers, however, this is not an option and all shellfish must be avoided.
Examples of shellfish include:
Abalone
Clams
Crab
Crawfish, crayfish
Lobster
Oysters
Scallops
Shrimp
Cockle, sea urchin
Mussels
Be careful with fried foods. Some restaurants use the same oil to fry shrimp, chicken, and French fries. Also, keep in mind that imitation shellfish may still contain shellfish as many manufactures add shellfish for flavoring. Before you use it, read the label to be sure.
better you consult a doctor about that allergy of yours. You should not take any suggestions about any medication or any thing of that nature from the answers posted to your question.
Consult a doctor.