livedo

Livedo is a descriptive term for a purplish, mottled pattern that appears on the skin, caused by sluggish blood flow in the dermal microcirculation and dilation of superficial vessels. The pattern can be temporary or persistent and may occur alone or as part of a broader vascular or systemic condition.

Two common patterns are recognized. Livedo reticularis refers to a symmetric, netlike or lace-like pattern, typically on the limbs. It is often accentuated by cold and may be benign, especially in healthy children and young adults, but can be a sign of vascular reactivity. Livedo racemosa describes a more irregular, broken, branching pattern that tends to be persistent and less affected by temperature; it is more strongly associated with underlying disease and warrants further evaluation.

Causes of livedo range from benign physiological responses to serious pathology. Physiologic livedo reticularis can occur with cold exposure or during pregnancy. Pathologic forms may be linked to autoimmune or thrombotic conditions (such as antiphospholipid syndrome, vasculitis, or Sneddon syndrome), cryoglobulinemia, hyperviscosity syndromes, infections, or certain drugs. Livedo can also be seen in association with vascular occlusion disorders, including livedoid vasculopathy, which involves recurrent ulceration and scarring due to microvascular thrombosis.

Diagnosis is primarily clinical, based on pattern, distribution, and evolution. When a pathologic cause is suspected, a workup may include complete blood counts, coagulation studies, autoimmune serologies, inflammatory markers, cryoglobulins, and sometimes a skin biopsy to assess dermal vessels.

Management focuses on addressing the underlying cause. Benign livedo reticularis may require reassurance and protection from cold, while pathologic forms necessitate targeted treatment of the associated disease, with prognosis varying accordingly.