*5.2.2 Diagnostic factors for herpes simplex (HSV) esophagitis*

Esophagitis due to the HSV can be identified by discrete superficial ulcers in the upper/mid gullet in the absence of the linked plaques, in the appropriate clinical environment. On the other hand, Candida esophagitis ulceration usually manifests on a background of extensive formation of plaque. Double-contrast investigations can be used in the diagnosis of Candida and herpes esophagitis without performing an endoscopy. It is also important to undertake endoscopic evaluation for confirmation of diagnosis when radiographic findings are ambiguous or when the problem do not respond to the treatment given to them.

Drug-induced esophagitis and Crohn disease are other causes of small superficial ulcers in the upper/mid esophagus, but these diseases can be differentiated from infectious esophagitis via detailed and careful patient history.

### *5.2.3 Diagnostic factors for CMV esophagitis*

Endoscopy with biopsy is the most effective diagnostic tool for CMV. Large punched out lesions are seen in mid esophagus on inspection. Enlarged cells in the sub-epithelial layer with inclusions within the cells' nucleus and its cytoplasm can be seen in histological analysis of the lesions. Fluorescent staining with an immunoperoxidase stain is very specific in addition to the histological investigation. The diagnosis of CMV esophagitis cannot be made effectively with radiologic imaging tests like X-rays or CT scans alone, but they can be helpful in discovering of any resulting fistulae or strictures.

The presentation of large/giant ulcers in a patient may suggest the diagnosis of CMV esophagitis in AIDS patients because herpetic ulcers really becomes as big as those of infectious esophagitis, but giant/large ulcers can also be caused by HIV in HIV positive people.

Giant esophageal ulcers can also be caused by nasogastric intubation; endoscopic sclerotherapy; caustic injuries and oral medications, such as nonsteroidal anti-inflammatory drugs (NSAIDs), potassium chloride, and quinidine [13–15]. Efficient patient's clinical history is normally helpful in suggesting the correct diagnosis of CMV esophagitis [14, 15].

Again, CMV can be transmitted through many ways, which include mother to child transmission, which is common after birth and spreading of CMV through blood or sex, but transmission via tears, saliva, and skin contact is not common. Therefore patient education is very important in this regard.
