**Core Concept**
Lofgren syndrome is a form of acute sarcoidosis characterized by a specific triad of symptoms: bilateral hilar lymphadenopathy, erythema nodosum, and arthritis. It is a self-limiting condition with a good prognosis.

**Why the Correct Answer is Right**
Lofgren syndrome typically presents with a combination of these three features, which are a result of the immune system's response to the accumulation of granulomas in the lungs and other tissues. The correct answer is one that does not fit within this triad.

**Why Each Wrong Option is Incorrect**
**Option A:** Bilateral hilar lymphadenopathy is a key feature of Lofgren syndrome, making it incorrect.
**Option B:** Erythema nodosum is another characteristic feature of Lofgren syndrome, making it incorrect.
**Option C:** Arthritis is also a common feature of Lofgren syndrome, making it incorrect.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that Lofgren syndrome is a type of acute sarcoidosis, and its symptoms can vary, but the classic triad is a crucial diagnostic clue.

**Correct Answer:** D.