Final answer:
Streptococcal pharyngitis, or strep throat, is caused by the bacterium Streptococcus pyogenes and is treated with antibiotics. It is important to complete the full course of antibiotics to avoid antibiotic resistance. Differential diagnosis can include other conditions like infectious mononucleosis.
Step-by-step explanation:
The clinical scenarios presented describe cases of streptococcal pharyngitis, commonly known as strep throat, which is a bacterial infection that can cause sore throat, fever, swollen lymph nodes, and fatigue. A classic causative agent is Streptococcus pyogenes, a gram-positive bacterium described by Rebecca Lancefield in the 1930s. Accurate diagnosis is essential for the effective treatment of strep throat. Treatment typically involves the prescription of antibiotics, and it is crucial to complete the full course to prevent the development of antibiotic-resistant bacteria. In some scenarios, a differential diagnosis may include conditions such as infectious mononucleosis, which requires a different treatment approach.