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.
Guttate psoriasis. In guttate psoriasis, many small, red, scaly patches develop suddenly and simultaneously. Guttate psoriasis often occurs in a young person who has recently had strep throat or a viral upper respiratory infection. About half of people with skin symptoms of psoriasis also have abnormal fingernails.