Differential Diagnosis for Connective Tissue Disorder Causing ILD in Upper Lobe
- Single Most Likely Diagnosis
- Rheumatoid Arthritis (RA): RA is a common connective tissue disorder that can cause interstitial lung disease (ILD), often affecting the upper lobes. The presence of rheumatoid nodules, which can be found in the lungs, and the typical upper lobe predominance of the disease make RA a leading consideration.
- Other Likely Diagnoses
- Systemic Sclerosis (Scleroderma): While systemic sclerosis more commonly affects the lower lobes, it can also involve the upper lobes and is known to cause ILD. The disease's potential to cause pulmonary hypertension and its impact on the skin and other organs make it a significant consideration.
- Polymyositis/Dermatomyositis: These inflammatory myopathies can be associated with ILD, although the lung involvement is less common than in other connective tissue diseases. The presence of muscle weakness and characteristic skin findings can help in diagnosing these conditions.
- Do Not Miss Diagnoses
- Sjögren's Syndrome: Although less commonly associated with ILD compared to other connective tissue diseases, Sjögren's syndrome can cause significant lung disease, including ILD. Its diagnosis is crucial due to the potential for extraglandular manifestations, including lymphoma.
- Mixed Connective Tissue Disease (MCTD): MCTD combines features of lupus, scleroderma, and polymyositis, and it can cause ILD. The disease's overlap features and potential for severe organ involvement make it a critical diagnosis not to miss.
- Rare Diagnoses
- Relapsing Polychondritis: This rare autoimmune disorder can affect the cartilage and connective tissue, leading to respiratory symptoms, including ILD. Its rarity and the presence of other distinctive features, such as auricular chondritis, make it less likely but still a consideration in the differential diagnosis.
- Eosinophilic Granulomatosis with Polyangiitis (Churg-Strauss Syndrome): Now referred to as eosinophilic granulomatosis with polyangiitis, this condition is characterized by asthma, eosinophilia, and vasculitis, which can involve the lungs and cause ILD. Its rarity and distinct clinical features make it a less common but important diagnosis to consider.