Final answer:
The term used to describe the autoimmune condition caused by β hemolytic streptococcus that can affect multiple body systems including the heart is rheumatic fever.
Step-by-step explanation:
The condition caused by autoimmune β hemolytic streptococcus that affects the heart, joints, CNS, skin, and subcutaneous tissue is called rheumatic fever. This autoimmune disease results from an infection with Streptococcus pyogenes, the bacterium that causes strep throat. An immune response that mistakenly targets the heart tissue, due to molecular mimicry between the M protein of the streptococcus and proteins in the heart tissue, can lead to autoimmune attacks and subsequent damage. Rheumatic fever is particularly serious because it can cause irreversible damage to the heart valves and may lead to chronic health issues or heart disease.