（primary cutaneous amyloidosis）（lichenoedand macular amyloidosis）； It is a type of amyloidosis (an 1yfoidosis), which refers to a chronic skin disease in which amyloid is deposited in normal skin tissues without involving other organs.

The etiology of this disease is still unknown, which may be related to heredity and immunity. Studies on light microscopy, electron microscopy, histochemistry and immunology all confirmed that amyloid originated from epidermis, escaped from denatured epidermal cells into dermis, and was transformed into amyloid, which was deposited in dermal papilla.