Blood spasms and circulation irregularities due to cold temperature, vascular disease, rheumatologic disease and endocrine disease can cause livedo reticularis, or mottling of the skin, according to Mayo Clinic. Livedo reticularis creates a purplish net-like pattern, usually on the legs.
Livedo reticularis is sometimes related to calciphylaxis, a complication of kidney dialysis, albeit rarely, states Mayo Clinic. In addition, certain medicines used to treat multiple sclerosis can cause livedo reticularis as a side effect. Livedo reticularis usually does not warrant treatment. Mayo Clinic advises affected individuals to seek medical attention if pain or discomfort accompany livedo reticularis or if painful nodules or ulcers appear on the affected area.