Cheilitis | EPFL Graph Search

Cheilitis is a medical condition characterized by inflammation of the lips. The inflammation may include the perioral skin (the skin around the mouth), the vermilion border, or the labial mucosa. The skin and the vermilion border are more commonly involved, as the mucosa is less affected by inflammatory and allergic reactions. Cheilitis is a general term, and there are many recognized types and different causes. According to its onset and course, cheilitis can be either acute or chronic. Most cheilitis is caused by exogenous factors such as dryness (chapping) and acute sun exposure. Allergic tests may identify allergens that cause cheilitis. Chapped lips (also known as cheilitis simplex or common cheilitis) is characterized by the cracking, fissuring, and peeling of the skin of the lips, and is one of the most common types of cheilitis. While both lips may be affected, the lower lip is the most common site. There may also be burning or the formation of large, painful cracks when the lips are stretched. Chronic cheilitis simplex can progress to crusting and bleeding. Counterintuitively, constant licking of the lips causes drying and irritation, and eventually the mucosa splits or cracks. The lips have a greater tendency to dry out in cold, dry weather. Digestive enzymes present in the saliva may also irritate the lips, and the evaporation of the water in saliva saps moisture from them. Some children have a habit of sucking and chewing on the lower lip, producing a combination of cheilitis and a sharply demarcated perioral erythema. Treatment is usually successful with barrier lubricants, such as lip salve or Vaseline. Medical grade (USP) lanolin accelerates repair of the lips, and is used in some lip repair products. Sometimes the term "cheilitis simplex" is used interchangeably with cheilitis in general; however, exfoliative cheilitis is also sometimes stated to be the equivalent of chapped lips. Actinic cheilitis Also termed "solar cheilosis", actinic cheilitis is the result of chronic over-exposure to ultraviolet radiation in sunlight.

Models of continuum with microcrack distribution

Lalaonirina Rakotomanana Ravelonarivo

The present work compares the micromechanical approach and the continuum approach for modeling microcracked continuum. The first approach considers a distribution of microscopic cells including contacting lips (discontinuity of matter), and the second appr ...

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