['"Brain fog." This is the most common characteristic of gluten sensitivity. Kids with brain fog may often feel tired, or like they just got out of bed. ... ', 'Headaches or migraines. ... ', 'Dizziness.', 'Acne or rashes. ... ', 'Joint pain or numbness. ... ', 'Diarrhea, gas or constipation.', 'Distended stomach or bloating.']