This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Other disorders of bone, Subject name: Pediatrics
Juvenile idiopathic ahritis includes all the following categories EXCEPT: 
Select and explain. 
A. Psoriatic ahritis, B. Enthesitis related ahritis, C. Systemic ahritis, D. Reactive ahritis
D: Reactive ahritis
Answer: D: Reactive ahritis 
Explanation: Juvenile Idiopathic Ahritis includes : Systemic JIA- Systemic involvement seen Oligoaicular- Affects four or fewer joints, often the knee or ankle. Polyaicular ahritis, rheumatoid factor negative Polyaicular ahritis, rheumatoid factor positive Psoriatic ahritis Enthesitis-related ahritis Undifferentiated ahritis