2nd solid food: Organic Lettuce(過敏)

at 6 month and 2 wks, I got the organic lettuce from Trader Joe and hoped his tummy can tolerant it. since my baby is sensitive, i make sure not to give him to much solid food and only one at a time. but his lips and chin start to have rash again after i fed him the 1st day. so i stopped feeding him the 2nd day, but the rash continued for 1 week. The Chinese doctor suggest us to give him some 甘草水去胎火. so we will give it a try and see if it'll get better.