Acquired reactive perforating collagenosis is a perforating dermatosis characterized by transepidermal elimination of collagen. It is frequently associated to diabetes mellitus and chronic renal insuffciency, but it is also related to other systemic diseases. The lesions tend to resolve once the underlying condition is treated. We report two patients with the condition. A 65 year-old diabetic female on hemodialysis consulted for multiple itching cutaneous ulcers lasting one year. On physical examination, hyperpigmented papules and nodules were observed. A 65 year-old female with chronic renal failure in hemodialysis consulted for itching lesions in hands, forearms and arms. On physical examination, hyperpigmented lesions with ulcers, erosions and crusts were observed. In both cases, the pathological study of the lesions disclosed a reactive perforating collagenosis.