This organism is found in the mouths of  about 40% of healthy individuals, and it is considered by some to be normal commensal component of the oral microbiota. However, Candida shows dimorphism, namely a yeast form which is thought to be relatively harmless and a pathogenic hyphal form which is associated with invasion of host tissues. Potassium hydroxide preparation is recommended by some to help distinguish between the harmless and the pathogenic forms, and thereby highlight which cases of angular cheilitis are truly caused by Candida. The mouth may act as a reservoir of Candida that reinfects the sores at the corners of the mouth and prevents the sores from healing. A lesion caused by recurrence of a latent herpes simplex infection can occur in the corner of the mouth. This is herpes labialis (a cold sore), and is sometimes termed "angular herpes simplex". A cold sore at the corner of the mouth behaves similarly to elsewhere on the lips, and follows a pattern of vesicle (blister) formation followed by rupture leaving a crusted sore which resolves in about 7–10 days, and recurs in the same spot periodically, especially during periods of stress. Rather than utilizing antifungal creams, angular herpes simplex is treated in the same way as a cold sore, with topical antiviral drugs such as aciclovir. Irritation contact dermatitis
22% of cases of angular cheilitis are due to irritants. Saliva contains digestive enzymes, which may have a degree of digestive action on tissues if they are left in contact.
Approximately 10 percent of patients may have other family members who have aortic aneurysms. It is also important to note that individuals with a history of aneurysms in other parts of the body have a higher chance of developing a thoracic aortic aneurysm. Diagnosis
Thoracic aortic aneurysm is defined as a cross-sectional diameter exceeding the following cutoff:

4.5 cm in the United States
4.0 cm in South KoreaA diameter of 3.5 cm is generally considered dilated. However, average values vary with age and size of the reference population, as well as different segments of the aorta. Screening
Guidelines were issued in March 2010 for early detection of thoracic aortic disease, by the American College of Cardiology, the American Heart Association, and other groups. Among the recommendations:

First-degree relatives of people with thoracic aortic aneurysm or dissection should have aortic imaging to identify asymptomatic disease. People with symptoms suggestive of thoracic aortic dissection should be routinely evaluated "to establish a pretest risk of disease that can then be used to guide diagnostic decisions." People diagnosed with Marfan syndrome should immediately have an echocardiogram to measure the aorta and followed up six months later to check for aortic enlargement. Treatment
The size cut off for aortic aneurysm is crucial to its treatment. A thoracic aorta greater than 4.5 cm is generally defined as aneurysmal, while a size greater than 6 cm is the distinction for treatment, which can be either endovascular or surgical, with the former reserved for pathology at the descending aorta.Indication for surgery may depend upon the size of the aneurysm.