Cut gluten out and my cystic acne of 3 years disappeared in 2 weeks. i tested negative for celiac antibodies. what is happening?

Possibilities: A negative test does not rule out celiac disease. Accepting the possibility of a false negative test I see 2 more possibilities: your acne is the result of a food allergy that involves mostly gluten rich food or it is a simple coincidence. A wild way to tell would be to reintroduce gluten in your diet. Thank you for sharing a very interesting finding and trusting the Health Tap medical community.