Rheumatologic, immunologic, and other allergic disorders encompass a wide range of medical conditions that affect the immune system and musculoskeletal system. Rheumatologic disorders like rheumatoid arthritis and lupus involve the immune system mistakenly attacking healthy tissues, leading to inflammation, joint pain, and other symptoms. Immunologic disorders encompass various autoimmune diseases where the immune system loses its ability to distinguish between self and foreign invaders.