Antigen—A foreign protein to which the body reacts by making antibodies
Conjunctivitis—An inflammation of the membrane surrounding the eye; also known as pink-eye.
Lymphocyte—A type of white blood cell. Lymphocytes play an important role in fighting disease.
Pharynx—The pharynx is the part of the throat that lies between the mouth and the larynx or voice box.
Toxin—A poison. In the case of scarlet fever, the toxin is secreted as a byproduct of the growth of the streptococcus bacteria and causes a rash.
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