[Bullous amyloidosis]

The occurrence of skin damage during systemic amyloidosis is common, but the appearance of bullous lesions is rare. Only twenty-seven cases have been reported in the literature. We report our observation of bullous amyloidosis during progression of renal amyloidosis.

A 61 year-old man, presented with white, soft, palpebral edemas of the lower limbs, without scutulum involvement, associated with a large cubital nerve that had appeared in March 1997. Biological explorations revealed a nephrotic syndrome. Pathologic study of the renal biopsy concluded in amyloidosis. Treatment with colchinine stabilized the renal damage. One year later, a non-pruriginous, papular and bullous eruption occurred, localized essentially in the axillary and inguinal-crural folds of the forearms and legs. In the presence of an amyloidal deposit and intra-epidermal detachment, the cutaneous biopsy was evocative of bullous amyloidosis. The search for concomitant myeloma was negative. Treatment with colchinine was effective. The bullous lesions disappeared after 2 months, and 21 months later, renal damage was still stable.

These particularities in evolution are exceptional and have never been described. A hypothetical modification in the physico-chemical properties of the amyloidal protein might explain the bullous eruption and stabilization of renal damage.