Search results
Results from the WOW.Com Content Network
Lichen planus may be categorized as affecting mucosal or cutaneous surfaces.. Cutaneous forms are those affecting the skin, scalp, and nails. [10] [11] [12]Mucosal forms are those affecting the lining of the gastrointestinal tract (mouth, pharynx, esophagus, stomach, anus), larynx, and other mucosal surfaces including the genitals, peritoneum, ears, nose, bladder and conjunctiva of the eyes.
Lichen simplex chronicus (LSC) is thick leathery skin with exaggerated skin markings caused by sudden itching and excessive rubbing and scratching. [1] It generally results in small bumps, patches, scratch marks and scale. [1] It typically affects the neck, scalp, upper eyelids, ears, palms, soles, ankles, wrists, genital areas and bottom. [1]
Lichen nitidus is a chronic inflammatory disease of unknown cause [1] characterized by 1–2 mm, discrete and uniform, shiny, flat-topped, pale flesh-colored or reddish-brown papules [2] [3] that may appear as hypopigmented against dark skin.
Lichen sclerosus (LS) is a chronic, inflammatory skin disease, of unknown cause, which can affect any body part of any person, but has a strong preference for the genitals (penis, vulva), and is also known as balanitis xerotica obliterans when it affects the penis. Lichen sclerosus is not contagious.
One reason the greenshield lichen can be more commonly found than other lichen species is because it is relatively tolerant of pollution. Lichens are often used to monitor air quality.
Lichenicolous lichens are relatively common; a study in Italy found that 189 of 3005 lichenised species (about 6%) were lichenicolous. [19] These lichens show distinct biological and ecological characteristics. They are predominantly crustose, mostly have green, non-trentepohlioid algae as photobionts, and primarily reproduce sexually.
Lichen striatus impacts the skin and nails. It is seen as an unbroken or disrupted, linear band consisting of small tan, pink or flesh colored papules. The papules can be smooth, flat topped or scaly. The band of lichen striatus varies from a few millimeters to 1-2cm wide and extends from a few centimeters to the complete length of the extremity.
Two obstacles are often encountered when eating lichens: lichen polysaccharides are generally indigestible to humans, and lichens usually contain mildly toxic secondary compounds that should be removed before eating. Very few lichens are poisonous, but those high in vulpinic acid or usnic acid are toxic. [147]