**Core Concept**
Primary extraglandular Sjögren's syndrome (p-EGSS) refers to the presence of systemic manifestations beyond the typical salivary and lacrimal gland involvement in Sjögren's syndrome, without underlying autoimmune rheumatic disease (AIRD) or other systemic conditions. This condition can manifest through various organs and systems, making it crucial for clinicians to be aware of the wide range of potential manifestations.

**Why the Correct Answer is Right**
The correct answer is determined by understanding the typical and atypical presentations of p-EGSS. This condition can involve various organs, including the skin, joints, lungs, kidneys, and nervous system, among others. The presence of systemic manifestations, such as interstitial lung disease, vasculitis, or neuropathy, is a hallmark of p-EGSS. In contrast, the absence of skin involvement, such as skin ulcers or lupus-like lesions, is more characteristic of secondary EGSS or another underlying AIRD.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because skin involvement is a common manifestation in primary extraglandular Sjögren's syndrome, often presenting as dry skin or skin ulcers.
**Option B:** This option is incorrect because joint involvement is a common feature in primary extraglandular Sjögren's syndrome, presenting as arthritis or arthralgia.
**Option C:** This option is incorrect because kidney involvement is a recognized manifestation in primary extraglandular Sjögren's syndrome, often presenting as interstitial nephritis or vasculitis.

**Clinical Pearl / High-Yield Fact**
To remember the key differences between primary and secondary EGSS, recall that primary EGSS typically presents with systemic manifestations without underlying AIRD, whereas secondary EGSS is characterized by the presence of AIRD or another underlying condition.

**Correct Answer: D**