L'artériolopathie calcifiante urémique et non urémique : urgence diagnostique et thérapeutique

Calcific arteriopathy (CA), also commonly known as calciphylaxis, is a disease carrying a poor prognosis. It is seen primarily in patients with chronic renal insufficiency (CRI), particularly those on haemodialysis (HD), where it is referred to as uraemic calcific arteriopathy (UCA), but it also occurs outside this setting, in which case it is known as non-uraemic calcific arteriopathy (NUCA). It is caused by thrombotic cutaneous arteriolar microangiopathy associated with fine calcium deposits in the media associated with hyperplasia of the intima of the dermal and hypodermal arterioles. Its course comprises two phases: a silent phase in which the arteriolar abnormalities begin, followed by a symptomatic phase, frequently triggered by specific factors, with sudden appearance of necrotic ischaemic plaques on the skin. Several clinical forms exist, proximal, distal and mixed, depending on the main site of the lesions. The prognosis is poor due to septic complications and the involvement of other organs. Diagnosis is based on the patient's history, clinical examination, laboratory examinations and skin biopsy with Von Kossa staining. The physiopathology, which is complex and is becoming increasingly well understood, involves high phosphorous and calcium levels and hyperparathyroidism, as well as other factors (inflammation, factors promoting or inhibiting calcification, coagulation disorders and traumatisms). Treatment involves a multidisciplinary and medical-surgical approach.