Livedo reticularis appears as a “faint, lace-like web spreading across the skin in shades of purple and blue.” While often harmless, it can sometimes signal serious illness. It forms when blood in small vessels flows unevenly or pools, making some areas appear discolored. The pattern usually darkens in cold and fades when warmed, which is why many people overlook it.

There are two types: Primary livedo reticularis, usually harmless and caused by cold temperatures, and Secondary livedo reticularis, which “persists regardless of temperature” and may indicate conditions such as autoimmune diseases, vascular problems, or blood clotting disorders.

Common causes include cold exposure, vascular or autoimmune diseases like lupus, and certain medications. Rarely, it’s linked to severe conditions like Sneddon’s syndrome or polyarteritis nodosa.

Doctors diagnose it through physical exams, blood tests, and sometimes imaging or skin biopsy. Treatment depends on the cause—“keeping warm and avoiding sudden cold exposure” may be enough for mild cases, while serious ones might require anticoagulants or immunosuppressants.

If the pattern “doesn’t fade with warmth” or is accompanied by pain, ulcers, or neurological symptoms, medical evaluation is essential. Your skin may be alerting you to something deeper happening inside.