Fig. 84.—Marked symmetry of all lesions. Illinois case. (From Lavinder and Babcock.)
A final cachexia, with dementia, loss of control of the vesical sphincter and a terminal diarrhoea, marks the end. Recurrences of clinical manifestations each spring, or possibly skipping a year, are striking features of the disease. While the skin and alimentary tract disturbances are usually in abeyance in the winter, this holds to less degree with the nervous symptoms.
The Diagnostic Triad
We may then state that in a typical case we have the diagnostic triad or pellagrous symptom-complex of (1) symmetrical sharply delimited erythemas of certain portions of the skin surface exposed to the sun with (2) alimentary tract disturbances of stomatitis, epigastric and substernal soreness and burning, with pyrosis and a recurring diarrhoea and (3) neurological manifestations in which a prodromal neurasthenia is followed by paraesthesias, in which burning sensations are prominent, at times leading to suicide by drowning, with alterations of deep reflexes, tremors and, in more advanced stages, a confusional insanity.
Burning sensations are noted in mouth, gullet and stomach as well as of the skin. Then too a burning sensation may be complained of in the area formerly the seat of a pellagrous eruption. The palms of the hands and soles of the feet often give a burning sensation.
One of the characteristic features of pellagra is the periodic recurrences in spring, with almost complete cessation of skin and alimentary tract symptoms in the winter and, again, the tendency in many cases for one group of symptoms to overshadow the symptoms which usually accompany them. These periodic recurrences may well be associated with seasonal variation in diet.
Stages in Pellagra.—For many reasons it is peculiarly difficult to recognize stages but for convenience many authors describe the disease under a prodromal, 1st, 2d and 3d stage.
These stages have reference solely to the degree of severity of the manifestations and a case may never progress beyond the 1st stage, although recurring for a number of years. Again a case may rapidly progress to the 2d stage and even run through the 3d or cachectic stage in a few months. We must not consider these stages as tending to follow in sequence as we do in connection with the stages of syphilis.
The prodromal manifestations of neurasthenia, malaise, loss of weight, loss of strength, vertigo and digestive disturbances would be suited to many other diseases, especially tuberculosis, and they are rarely recognized as belonging to pellagra until the appearance of typical skin or other symptoms brings about their association with pellagra. There is little definite information as to the period of incubation although Sandwith places it at from nine to twelve months.