I don't want to get into an argument about what diseases Alexandra was suffering from, but there is a fairly persuasive summary of her symptoms as a possible porphyria sufferer on pp.168-170 of the Book "Royal Maladies: Inherited Diseases in the Ruling Houses of Europe" (2008), by Alan R. Rushton, M.D. Ph.D. The author also pointed out that her mother Alice and her sister Elizabeth also suffered from some of the same symptoms, as did their ancestor Queen Victoria. They were all descendants of King George III, who almost certainly did have that disease.