A little part of my 10 year old sons lower lip swelled up after eating sushi with crab meat and went back to normal after about 2 hours.could he be allergic to shell fish. he has eaten shrimp in the past without any issue. he is g6pd positive?

The trigger could be anything consumed at the same time. Any seasoning on the item/the meat/the wrap contents/etc.

Shellfish is a common food allergy. Avoid all forms until further evaluated. Benadryl is often effective in reducing the symptoms. Discuss a food allergy panel with your Pediatrician. The timing is consistent with the exposure I agree that many ingredients may also trigger this reaction. Watch for signs of shortness of breath and worsening.