Esophagitis is frequently caused by the backflow of acid-containing fluid from the stomach to the esophagus, a condition called gastroesophageal reflux. An autoimmune disorder called eosinophilic esophagitis also causes this condition. 
Esophageal infection may be due to fungi, yeast (especially Candida infections), or viruses such as herpes or cytomegalovirus.
What causes Esophagitis?
Esophagitis is frequently caused by the backflow of acid-containing fluid from the stomach to the esophagus, a condition called gastroesophageal reflux. An autoimmune disorder called eosinophilic esophagitis also causes this condition. 
Esophageal infection may be due to fungi, yeast (especially Candida infections), or viruses such as herpes or cytomegalovirus.