Mondo Description Diffuse cutaneous mastocytosis (DCM) is a rare form of cutaneous mastocytosis (CM) characterized by generalized erythroderma, various degrees of blistering, skin with a ''peau d'orange'' appearance and the accumulation of mast cells in the skin. At least two DCM variants are recognized, one with extreme blistering (Bullous DCM) and one with infiltrations (Pseudoxanthomatous DCM).