The book provides an introduction to the differential diagnosis and decision-making in pediatric rheumatological diseases through typical and real cases. One of the aspects in the discussion of various case scenarios is the avoidance of errors and error management. The casebook is useful for specialists and trainees in pediatrics, young doctors, and anyone on the path to specialization in pediatric rheumatology. The translation was done with the help of artificial intelligence. A subsequent human revision was done primarily in terms of content.