We herein report a case of mastocytosis with unusual cutaneous manifestations resembling pseudoxanthoma elasticum or xanthoma which were exaggerated on the intertriginous areas including axillae, groin and neck in a 39-year-old woman. It was characterized by multiple yellowish papules and plaques with a cobblestone appearance. In addition, there were diffuse red-dish macules and papules of varying sizes mainly on the trunk and extremities. Histopathologic findings showed a very dense infiltrate of large numbers of round to oval cells in the upper and mid dermis. These cells revealed metachromasia on the toluidine blue stain. She also had hepatosplenomegaly and some evidence of bone marrow involvement. There was significant improvement in,the skin lesions with psoralen plus ultraviolet A(PUVA) therapy and potent topical corticosteroid.