[Digital necrosis revealing cold agglutinin disease: Treatment with rituximab]

BACKGROUND

Digital necrosis is rarer than lower limb necrosis and constitutes a medical or surgical emergency. Etiological evaluation is required. Cold agglutinin disease is a cause of digital necrosis but diagnosis is difficult.

PATIENTS AND METHODS

Herein we report the case of a 57-year-old man presenting recent paroxysmal acrosyndrome of the left hand subsequently complicated by digital necrosis following occupational exposure to cold in his work as a forklift driver. After etiological evaluation, a diagnosis of primary cold agglutinin disease was made. Intravenous rituximab and topical treatment resulted in complete healing.

DISCUSSION

Cold agglutinin disease is a rare type of auto-immune hemolytic anemia. Following exposure to cold, paroxysmal cutaneous signs are frequent. The disease may be either primary or secondary with B-cell lymphoproliferative disorder, auto-immune disease or infection. A thorough workup is required. To date, the treatment combining the best positive response rate and good safety is rituximab in weekly perfusions over a 1-month period.

[Digital ischemia revealing multiple myeloma]

Digital ulcers generally arise in a context of microangiopathy-related focal ischemia. In women, connective tissue diseases are the main etiology, while in men the cause is often diffuse arterial disease, e.g. Leo-Buerger disease, or emboligenic heart disease. A paraneoplastic origin of digital necrosis due to ischemia is rarely reported. A 75-year-old man presented with cyanosis of the fingertips and toes that had begun one month earlier. The physical examination found pulp ulcers on the fingers and toes of both hands and feet. Two weeks later, necrotic damage developed distally, with no other associated symptoms. Blood tests were suggestive of Kahler disease; immunodeficiency disorders tests were negative; the cyroglobulin test was positive. Multiple-drug chemotherapy was followed by clinical improvement. Distal necrotic damage is a frequent inaugural symptom in vascular disease. If the common causal mechanisms (iatrogenic, occupational, toxic, atheromatous, emboligenic heart disease, or systemic disease) have been ruled out, it is important to search for a blood disorder or cancer as the cause of distal necrotic damage.