The boils on Karl Marx's butt

I never read biographies of Karl Marx or even long articles about him without having to read about the boils on his butt: "and grew fist-size boils, which Sperber thinks were caused by an autoimmune disorder but which may have been a symptom of his liver disease." What is the story there? That Marxism should be discredited because Marx had boils on his butt? Western (especially American) hostility to Marxism and Marx remains as insane as it was during the Cold War.