A tracheoesophageal fistula (TEF, or TOF; see spelling differences) is an abnormal connection (fistula) between the esophagus and the trachea. TEF is a common congenital abnormality, but when occurring late in life is usually the sequela of surgical procedures such as a laryngectomy. Presentation
Tracheoesophageal fistula is suggested in a newborn by copious salivation associated with choking, coughing, vomiting, and cyanosis coincident with the onset of feeding. Esophageal atresia and the subsequent inability to swallow typically cause polyhydramnios in utero. Rarely it may present in an adult. Complications
Surgical repair can sometimes result in complications, including:
Stricture, due to gastric acid erosion of the shortened esophagus
Leak of contents at the point of anastomosis
Recurrence of fistula
Gastro-esophageal reflux disease
Dysphagia
Asthma-like symptoms, such as persistent coughing/wheezing
Recurrent chest infections
Tracheomalacia

Associations
Neonates with TEF or esophageal atresia are unable to feed properly. Once diagnosed, prompt surgery is required to allow the food intake. Some children experience problems following TEF surgery; they can develop dysphagia and thoracic problems. Children with TEF can also be born with other abnormalities, most commonly those described in VACTERL association - a group of anomalies which often occur together, including heart, kidney and limb deformities. 6% of babies with TEF also have a laryngeal cleft. Cause
Congenital TEF can arise due to failed fusion of the tracheoesophageal ridges after the fourth week of embryological development.A fistula, from the Latin meaning a pipe, is an abnormal connection running either between two tubes or between a tube and a surface. In tracheo-esophageal fistula it runs between the trachea and the esophagus.
Angular cheilitis (AC) is inflammation of one or both corners of the mouth. Often the corners are red with skin breakdown and crusting. It can also be itchy or painful. The condition can last for days to years. Angular cheilitis is a type of cheilitis (inflammation of the lips).Angular cheilitis can be caused by infection, irritation, or allergies. Infections include by fungi such as Candida albicans and bacteria  such as Staph. aureus. Irritants include poorly fitting dentures, licking the lips or drooling, mouth breathing resulting in a dry mouth, sun exposure, overclosure of the mouth, smoking, and minor trauma. Allergies may include substances like toothpaste, makeup, and food. Often a number of factors are involved. Other factors may include poor nutrition or poor immune function. Diagnosis may be helped by testing for infections and patch testing for allergies.Treatment for angular cheilitis is typically based on the underlying causes along with the use of a barrier cream. Frequently an antifungal and antibacterial cream is also tried. Angular cheilitis is a fairly common problem, with estimates that it affects 0.7% of the population. It occurs most often in people in their 30s to 60s, and is also relatively common in children. In the developing world, iron, vitamin B12, and other vitamin deficiencies are a common cause. Signs and symptoms
Angular cheilitis is a fairly non specific term which describes the presence of an inflammatory lesion in a particular anatomic site (i.e. the corner of the mouth).