What Cause Scarlet Fever?

Scarlet fever is a disease that attacks the mucous membranes of the nose and throat and usually produces a skin rash.
The infection is caused by bacteria belonging to the streptococcus group. While the disease itself is no longer considered serious, it may be followed by other more serious illnesses. Two of the worst of these are rheumatic fever and nephritis (a kidney disease). Scarlet fever occurs chiefly in the winter. Half the cases of scarlet fever occur among children between the ages of three and eight, and 90 per cent among persons under fifteen. One attack of scarlet fever usually makes a person immune to this disease.
Many people carry the germs of the disease in the nose or throat without being ill. They pass the bacteria to others by coughing or sneezing. Two to five days after a person has been exposed to it, the sickness begins with fever, chills, and vomiting. The throat becomes very sore. It is red, swollen, and covered with white patches. The tongue is also red and dotted with tiny swellings.
On the second day, small, bright red spots begin to spread over the body, arms and thighs. This rash is caused by a toxic (poisonous) substance given off by the bacteria. This toxin acts on small blood vessels in the skin, and enlarges them.
After about seven or eight days, the rash fades, the fever lessens, and the throat clears.