Anetoderma
Anetoderma is a benign but uncommon disorder that causes localized areas of flaccid or herniated sac-like skin due to a focal reduction of dermal elastic tissue.[6] Primary anetoderma is an idiopathic development of atrophic lesions in skin areas that appeared normal prior to the onset of atrophy.It has been linked to a variety of conditions, such as acne,[8] urticaria pigmentosa,[9] syphilis,[6] leprosy,[8] granuloma annulare,[10] insect bites,[11] and antiphospholipid syndrome.The familial form usually appears in the first ten years of life and may show up only as skin manifestations, but it can also be linked to ocular, neurological, and bony abnormalities.[18] Under a microscope, the epidermis of anetoderma exhibits a nearly total loss of elastic fibers in the reticular and papillary dermal layers.