n 1993, a new theory on Jack London's fatal disease came to light in an article in the Journal of Rheumatology written by Charles W. Denko, M.D., of the Division of Rheumatic Disease, Case Western Reserve University School of Medicine. Based upon his study of London's symptoms, beginning with the self-diagnosis of scurvy in the Klondike in 1897-98, Denko believed the author died of systemic lupus erythematosus. This chronic disease, in which the body's immune system attacks connective tissue causing inflammation, is "systemic" when it attacks such systems as kidneys, joints, and the heart.

Denko asserted that London displayed lupus clues when he reported contracting scurvy—with bleeding, swollen gums and joint pain—in the Klondike in 1896, while others in his party, eating the same diet, showed no signs of the ailment.

In June 1898, at Anvik, Alaska, London wrote of eating fresh potatoes and a can of tomatoes for his scurvy which he said "has now almost crippled me from my waist down. Right leg drawing up, can no longer straighten it, even in walking must put my whole weight on toes." London said his condition improved after eating the vegetables but Denko stated that the scurvy self-diagnosis was unlikely since hundreds of milligrams of vitamin C are required for a cure, many times what could have been contained in the vegetables London consumed.

Denko wrote that the symptoms London described "could be better explained as an attack of acute lupus involving the mouth and joints, two areas commonly attacked by episodic lupus."

London continued to have mouth and gum problems, the rheumatic specialist said, together with severe headaches, facial neuralgia, pulmonary problems, grippe, bronchitis, colds, chest pains, and pleurisy (diagnosed on the transport when London was en route to Mexico in 1914), all common manifestations of lupus.

Denko said that London's skin problems—recurring rashes, urticaria, itching and painful hands and peeling skin, thickened toenails, the other dermatological disorders he experienced in the South Seas—were flare-ups of lupus rather than the diagnosed psoriasis and pellagra. For the author's repeated attacks of fever, diagnosed as malaria, he received antimalarial drugs such as quinine, which Denko pointed out is a modern treatment for lupus.

Lupus erythematosus, Dr. Denko wrote, was the name used by early observers of the disease to describe the severe lesions on the faces of untreated victims that resembled wolf bites. "London's fame, in part, was due to writing about wolves" he said. "Even his beautiful, ill-fated dream house was given a 'wolf' association....It is ironic that Jack London himself succumbed to an acute flare of lupus, the wolf disease."