Livedo reticularis is a common skin finding consisting of a mottled reticulated vascular pattern that appears as a lace-like purplish discoloration of the skin. The discoloration is caused by reduction in blood flow through the arterioles that supply the cutaneous capillaries, resulting in deoxygenated blood showing as blue discoloration. This can be a secondary effect of a condition that increases a person's risk of forming blood clots, including a wide array of pathological and nonpathological conditions. Examples include hyperlipidemia, microvascular hematological or anemia states, nutritional deficiencies, hyper- and autoimmune diseases, and drugs/toxins. The condition may be normal or related to more severe underlying pathology. Its differential diagnosis is broadly divided into possible blood diseases, autoimmune diseases, cardiovascular diseases, cancers, and endocrine disorders. It can usually be diagnosed by biopsy. It may be aggravated by exposure to cold, and occurs most often in the lower extremities. The condition's name derives from the Latinlivere which means bluish, and reticular which refers to the net-like pattern.
Causes
A number of conditions may cause the appearance of livedo reticularis:
Cutis marmorata telangiectatica congenita, a rare congenital condition
Sneddon syndrome – association of livedoid vasculitis and systemic vascular disorders, such as strokes, due to underlying genetic cause
Idiopathic livedo reticularis – the most common form of livedo reticularis, completely benign condition of unknown cause affecting mostly young women during the winter: It is a lacy purple appearance of skin in extremities due to sluggish venous blood flow. It may be mild, but ulceration may occur later in the summer.
Secondary livedo reticularis:
*Vasculitis autoimmune conditions:
**Livedoid vasculitis – with painful ulceration occurring in the lower legs
Livedo reticularis is diagnosed by its clinical appearance and history. No further test or examination confirms idiopathic livedo reticularis, however, further investigations may be undertaken where an underlying cause is suspected such as skin biopsies, or blood tests for antibodies associated with antiphospholipid syndrome or systemic lupus erythematosus.
Treatment
Other than identifying and treating any underlying conditions in secondary livedo, idiopathic livedo reticularis may improve with warming the area. A further treatment option for livedo reticularis of the lower limbs is chemical lumbar sympathectomy. Scientists at Peking University have developed a protocol to minimise complications traditionally linked to this procedure. Known as "selective chemical lumbar sympathectomy" it involves injecting an inactivating agent behind the anterior fascia, which only targets gray rami communicantes, to help achieve therapeutic efficacy in vasodilation.
