Palmar digital vein thrombosis in a patient with COVID-19.

A 53‐year‐old woman presented with a 3‐week history of intermittent blue nodules on the palmar digits of her hands, coincident with COVID‐19 infection. The patient carried the factor V Leiden mutation. She had a strong family history but no personal history of venous thromboembolism. She had not undertaken any strenuous or heavy manual labour prior to the onset of the nodules.

On physical examination, a soft, nontender subcutaneous blue nodule, 5 mm in size, was seen near the proximal interphalangeal joint (PIPJ) on the palmar aspect of the left third digit (Fig. 1). Full physical inspection of the skin revealed no other similar cutaneous manifestations. The patient was diagnosed with palmar digital vein thrombosis.

Figure 1

A small, soft, nontender, subcutaneous blue nodule, 5 mm in size, on the left third palmar digit in a patient with COVID‐19.

Thrombosis of the palmar digital veins causing cutaneous nodules is rare. Digital vein thrombosis was first described in 1936 by Jadassohn. In the few cases reported, patients were generally women, with an age range of 35–65 years. The nodules are commonly described on the palmar aspect of the digits and found at or near the level of the PIPJ, but they can also be located over the middle or distal interphalangeal joint. The condition appears to have a predominance for the fourth digit but it does not discriminate between dominant and nondominant hands. Pain, tenderness, erythema and warmth are features that are suggestive of this diagnosis.

There are four functional systems draining blood from the digits: the arborizing veins, venous arch, and the deep and superficial axial veins. Thrombosis is more commonly reported in the superficial axial veins, particularly the palmar veins, which are small in diameter and contain more valves. The role of hypercoagulable states in digital vein thrombosis is poorly understood and has not been formally investigated. Lechner et al. described a patient who developed deep vein thrombosis of the legs with recurrent lung emboli, which were preceded by digital vein thrombosis. In 2002, Hofer described an isolated case of antiphospholipid syndrome causing digital vein thrombosis.

The diagnosis of palmar digital vein thrombosis is based mainly on clinical symptoms although noninvasive assessment by ultrasonography can be undertaken. The mainstay of treatment is conservative therapy, including massage and compression. Surgical removal can be considered if the condition is painful or progressive.

The marked inflammation triggered by COVID‐19 infection results in coagulopathy and endothelial dysfunction. The ensuing hypercoagulable state, termed ‘thromboinflammation’, can manifest as thrombosis in both large and small blood vessels. We hypothesize that the hypercoagulability induced by COVID‐19, combined with the patient’s known thrombophilia, resulted in digital vein thrombosis.

To our knowledge, this is the first description of digital vein thrombosis in a patient with COVID‐19, adding to the wide spectrum of thrombotic manifestations found in this illness. The patient was treated conservatively and had a good outcome.