No, it isn't scary to me. The Masque was مزید of a metaphor. He's actually writing about Tuberculosis. Because the woman he cared for so much including his wife died from it. It actually saddened me مزید than anything.
"THE "Red Death" had long devastated the country. No pestilence had ever been so fatal, یا so hideous. Blood was its Avatar and its مہر -- the redness and the horror of blood. There were sharp pains, and sudden dizziness, and then profuse bleeding at the pores, with dissolution."
It is not scary at all. It has a great atmosphere where we can explore the surrealisms of the story. The red death was like a representation of the blood and the war. That`s why I love this storie. But it`s not scary.