It is a risk to venture a prognosis in pellagra because cases that seem mild may suddenly become severe. The extent of the skin lesions does not parallel the severity of the case although moist or gangrenous dermatitis is usually seen only in severe cases.
When fever comes on the prognosis of the case is unfavorable and when the mental manifestations are prominent the prognosis is bad.
The Italian physicians give a more hopeful prognosis than the American ones, which is easily understood when it is considered that American mortality from pellagra is given as from 25 to 39.10%. That of Italy is certainly below 10% and recent statistics have shown a mortality of only 3%. In the U. S. the mortality is now below 10%.
Of particular importance is the question of the liability to mental trouble. Singer states that about 40% of all cases of pellagra develop mental disturbances and that this incidence is much higher in cases presenting recurrences. In Italy it is estimated that from 5 to 10% of pellagrins become permanently insane.
The earlier a case of pellagra comes under treatment the more favorable the prognosis.
In the first stage the prognosis is very good but in the second, when there is more or less involvement of the central nervous system, it is much less favorable. In the third stage, or that of the terminal cachexia with marked mental deterioration, the prognosis is extremely bad. Each recurring attack makes the condition more serious. The older the patient the more serious the prognosis.
Prophylaxis and Treatment
Prophylaxis.—There does not seem to be any satisfactory evidence as to the contagiousness of pellagra, so that any method involving isolation is not indicated.
Even if the use of spoiled corn is not productive of pellagra it is certainly advisable to prevent its sale by state regulation.