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.
The rash is often associated with mild itching. Like other forms of psoriasis, guttate psoriasis tends to improve during the summer and worsen during the winter. Examination of the skin reveals characteristic lesions consisting of multiple, discrete drop-like salmon-pink papules. A fine scale may be seen on established lesions.