Which disease may arise from complications of chronic tonsillitis or pharyngitis due to streptococcus infection?

Rheumatic fever is a serious inflammatory condition that can develop as a complication of untreated or inadequately treated streptococcal throat infections, such as chronic tonsillitis or pharyngitis. The infection can lead to the development of antibodies that not only target the streptococcus bacteria but may also mistakenly attack the body's own tissues, particularly affecting the heart, joints, skin, and central nervous system. This autoimmune response can cause significant damage, especially to the heart valves, leading to rheumatic heart disease.

The other options, while related to infections, do not specifically arise from complications of streptococcal throat infections in the same manner. Endocarditis, for instance, involves an infection of the heart valves generally due to bacteria entering the bloodstream, but it is more commonly associated with other risk factors and pre-existing heart conditions. Myocarditis and pericarditis can also relate to infections but typically stem from viral causes rather than from streptococcus-related throat issues. Thus, rheumatic fever is uniquely positioned as a direct consequence of the body's response to a streptococcal infection in the throat, making it the correct answer.