Quote from: lakeswimr on February 11, 2016, 09:24:46 PM
Yes, even very large tests can be false positives.  the false positive rate is very high.  You can't diagnose a food allergy based only on test results.  It is not recommended to test a food unless you have a reason to suspect a food is an allergen.  Why did the allergist test you for watermelon?

That's good to know. I've been having problems like itching burning tongue and throat and lumps and pressure in my chest along with dry cough sometimes. I'm thinking its not allergy related considering I'm avoiding everything on the list. Seems everything I eat no matter what causes problems. So he wanted to test everything and to see if food allergies could be an cause.

Yes, even very large tests can be false positives.  the false positive rate is very high.  You can't diagnose a food allergy based only on test results.  It is not recommended to test a food unless you have a reason to suspect a food is an allergen.  Why did the allergist test you for watermelon?

My DD is allergic to watermelon!

What happened to her was a reaction to cantaloupe first - anaphylaxis.  (It was the exact same melon she had eaten a day or two before without incident)  Testing results at that point were positive to cantaloupe and honeydew melons.  Then a short time later a skin contact reaction on her face from watermelon that evolved to allergy to watermelon too.

For my DD, her allergist suggested it was because of her ragweed allergy.  That her allergy cup was full and her body said NO!   Same way due to her birch tree allergy, she went from eating pitted fruits safely to becoming allergic to them.

I too was surprised that fruit could cause anaphylaxis instead of OAS.

Quote from: rebekahc on February 05, 2016, 02:15:47 PM
Skin prick tests for foods are inaccurate and have a very high false positive rate.  Generally, it is not recommended to do a broad range of SPTs as a 'fishing expedition' because the high rate of false positives will lead to unnecessary avoiding of foods.  SPTs should be used when trying to narrow down the cause of a reaction when several foods could be culprits.  Unless you've been having reactions to the foods you tested positive to, there shouldn't be any need to avoid them.  Why was the SPT done?  Have you been having allergic reactions to foods?

Can a false positive manifest itself so severe though? It swole really big. I have had trouble with food. Mainly wheat/dairy which didn't come back anymore. Still paranoid to retry them. I told the doc when I ate corn chips my breathing gets very tight/sore throat. It was to test for that and an everything else to be sure nothing else was getting me.

Skin prick tests for foods are inaccurate and have a very high false positive rate.  Generally, it is not recommended to do a broad range of SPTs as a 'fishing expedition' because the high rate of false positives will lead to unnecessary avoiding of foods.  SPTs should be used when trying to narrow down the cause of a reaction when several foods could be culprits.  Unless you've been having reactions to the foods you tested positive to, there shouldn't be any need to avoid them.  Why was the SPT done?  Have you been having allergic reactions to foods?

Got a allergy prick test. Watermelon swelled instantly and got very big. The allergist even gave me an epipen. I knew oral allergy was a thing. But anaphalxis from watermelon? Luckily I think watermelon is the most disgusting fruit so I haven't eaten any in years.

What protein in watermelon causes reactions and what other fruits/veggies need to be avoided that might be in the same family. I think green beans came back slightly. Along with egg, corn, rice, pepper, sesame, and shellfish (FML).