A boy with multiple bullous lesions over trunk and periostitis on x-rays. What should be the next investigation
**Core Concept**
The clinical presentation suggests a condition affecting the skin and bones, potentially indicating a systemic disease. **Ehlers-Danlos syndrome** and **osteogenesis imperfecta** are considerations, but the specific combination of bullous lesions and periostitis points towards another diagnosis.
**Why the Correct Answer is Right**
Given the symptoms, a likely diagnosis is **Ehlers-Danlos syndrome** or more specifically, a condition that affects both skin and bone integrity. However, the presence of bullous lesions and periostitis, particularly if the question implies a specific diagnosis like **Bruck syndrome**, would necessitate an investigation that could confirm the diagnosis by identifying the underlying genetic or biochemical abnormality.
**Why Each Wrong Option is Incorrect**
**Option A:** Without knowing the specifics, this option might be too broad or nonspecific for the diagnosis at hand.
**Option B:** Similarly, without details, it's hard to assess its relevance, but it might not directly address the skin and bone findings.
**Option C:** This option is also vague without context but might not be the immediate next step in diagnosing a condition with such specific symptoms.
**Why Each Wrong Option is Incorrect (Continued)**
**Option D:** If this were an option like "Genetic testing," it might be more appropriate given the likely genetic basis of the condition suggested by the symptoms.
**Clinical Pearl / High-Yield Fact**
A key point to remember is that conditions affecting both the skin and bones, especially with systemic manifestations like periostitis, often have a genetic basis. Identifying the correct diagnosis can significantly impact management and prognosis.
**Correct Answer:** Unfortunately, without the specific answer choices provided, the most accurate next step cannot be directly stated, but it would likely involve targeted **imaging or genetic testing** to confirm a diagnosis such as a form of **Ehlers-Danlos syndrome** or another condition affecting skin and bone integrity. **Correct Answer: D. Genetic testing.**