canker rash and scarlatina
Today we know that scarlet fever is cause by a group A streptococci, easily treated with antibiotics. The bacteria which cause scarlet fever was first identified in 1884, but it was not until the discovery of penicillin in the 1920's that a cure could be found for this deadly disease. The disease progressed quickly after onset of the first symptoms usually fever and sore throat and death could occur within 48 hours.
Treatment was limited and ranged from the bizarre to the ineffective. The disease was passed via airborne particles as well as by direct contact. Multiple people in the same family might be infected and each be affected differently by the disease. Some might have a mild case while others died, depending on their reaction to the toxins released by the bacteria.
I don't want to know what that must have been like, watching your children struck down by disease, but it was a tragedy that occurred all to often to our ancestors.
Swedland and Donta, Scarlet Fever Epidemics of the Nineteenth Century, a case of an evolved pathogenic virulence.