noun. 1  a. A cylindrical, usually metal casing containing the primer and charge of ammunition for firearms. 2  A case filled with high explosives, used in blasting. 3  A small modular unit designed to be inserted into a larger piece of equipment: an ink cartridge; a disposable cartridge of caulking compound. A removable case containing the stylus and electric conversion circuitry in a phonograph pickup.
Guttate psoriasis causes a rash formed of drop-shaped salmon-pink areas on the chest, arms, legs and scalp. Guttate psoriasis. Red drop-like lesions are found on the skin. Image courtesy of Dr Hon Pak.
Plaque psoriasis is basically linked to an abnormal inflammatory reaction. Still, there are certain factors that precipitate the development of the skin disease. The following are considered the triggering environmental factors of plaque psoriasis: 1  Trauma or injury to skin. These may include cuts, burns and even insect bites. 2  Infection. This includes HIV- AIDS, which is basically a common ailment that can develop psoriasis. 3  Certain medications.