From David Duff's 'Alexandra, Princess and Queen'.....
"Fever, 'white leg' and rheumatism in the knee joint were not the sum of Alexandra's troubles. Her preganancy [with Louise] and illness had brought out in her the otosclerosis inherited from her mother. With each passing week she became more deaf. She was adult now, had endured long agony and been near to death. The deafness came down as a curtain between her and those who did not know her well. No longer could she keep pace with the smart chatter at social gatherings. She retreated into the small world which she knew best and loved the most, the world of her children and family, of her home and animals. Her interest also turned to the care of those who had suffered as she had done, to the help of those in trouble, to a love which covered all in need. She fought to stop the curtain falling between herself and Bertie, but she was hard pressed."
I haven't managed to ascertain what caused the scar on her neck; it was alleged, at the time of the negotiations for the marriage, when various people were attempting to discredit the Glucksburgs and so prevent the match, that it had been caused by scrofula, which was a complaint that, at that time, was synonymous with poverty and negligence. Apparently this information originated from a source close to Ernst of Coburg and Baron Stockmar; I think however it was , along with all the other falsehoods being perpetrated about Alexandra and her family, ultimately disproved.