History of the Peloponnesian War
Thucydides
Thucydides, Vol. 1-4. Smith, Charles Foster, translator. London and Cambridge, MA: Heinemann and Harvard University Press, 1919-1923.
That year, as was agreed by all, happened to be unusually free from disease so far as regards the other maladies; but if anyone was already ill of any disease all terminated in this.
In other cases from no obvious cause, but suddenly and while in good health, men were seized first with intense heat of the head, and redness and inflammation of the eyes, and the parts inside the mouth, both the throat and the tongue, immediately became blood-red and exhaled an unnatural and fetid breath.