<unk>  is a form of<unk>  which is not directly attributable to another medical condition.
It can be divided into three forms, depending upon age of onset: congenital<unk> ,<unk>  praecox, and<unk>  tarda.
It can be familial.<unk>  tarda occurs in patient above 35 years of age<unk> –distichiasis syndrome is a medical condition associated with the FOXC2 gene.:849
Primary lymphedema
Raynaud's disease
Leg ulcer
Carcinoma of the penis
Venous ulcer
Venous claudication
Plantar wart
Genital ulcer