This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Orthopaedics
[{'content': 'Periosteal reaction is not common in - \nSelect and explain. \nA. Syphilis, B. Gout, C. Osteomyelitis, D. Tuberculous dactylitis', 'role': 'user'}, {'content': "Answer: B \nExplanation: Periosteal reaction \n\nBesides covering the bone and sharing some of its blood supply with the bone, periosteum (particularly cambium layer) also produces bone when it is stimulated.\nPractically anything that breaks, tears, stretches, inflames or even touches the periosteum, stimulates the reactive bone formation by periosteum.\nThis is called periosteal reaction.\nImportant causes of periosteal reaction are:-\n\n\nInfection:- Osteomyelitis, Brodie's abscess, syphilis\nNeoplasms\n\n\nBenign: Osteoid osteoma\n\n\nMalignant: Ewing's sarcoma, osteosarcoma\nEosinophilic granuloma\n\n\nHealed stress fracture\nHypertrophic pulmonary osteoarthropathy Option d requires specific mention here\n\n\nRadiographically, the tubercular lesion of long bones is lytic with no or minimal periosteal reaction.\nTuberculosis of short tubular bones of the hands and feet (tubercular dactylitis) has a different appearance, the so-called spina ventosa, consisting of bony expansion and prominent periosteal reaction.", 'role': 'assistant'}]