I agree, it is gular edema.
Gular edema refers to the buildup of fluid under the skin in the area between under the arms of chameleons. It is not known specifically why this buildup occurs but it is speculated to be a symptom of a mineral imbalance (it is not clear which ones), or potentially an indication of liver or kidney disease. The best treatment in the experience of some is as much natural sunlight as possible, significantly increased hydration and ensuring adequate calcium supplementation with very limited phosphorus content in food and minimal supplementation of other vitamins to promote good kidney health. There is no medication to use or one treatment that has proven effective in every case. The amount of edema may fluctuate and seems to decrease most consistently when water intake increases. Sometimes the edema goes away with time, and sometimes it is permanent. For some reason edema is seen commonly with gravid females and it usually resolves once the eggs are laid
