Pulmonary-Renal Syndrome in ICD10

Background

This refers to a syndrome of lung and kidney involvement. It is NOT a disease, it is a syndrome that has numerous causes and multiple possible manifestations both in the lungs and the kidneys.
Most commonly, BUT NOT ALWAYS, it is due to one of another autoimmune disease
- The two most common causes are:
  - Wegener's granulomatosis
  - Goodpasture syndrome (hypersensitivity angiitis)
- However, other autoimmune diseases that can cause it include:
  - Systemic lupus erythematosis (SLE, lupus)
  - Scleroderma or CREST syndrome (systemic sclerosis)
  - Collagen-vascular overlap syndrome -- including Mixed Connective Tissue Disease (MCTD)
  - Collagen-vascular disease, NOS
  - Necrotizing vasculopathy/vasculitis, NOS
  - Dermatomyositis/polymyositis
  - Microscopic polyangiitis/polyarteritis
  - Churg-Strauss syndrome (eosinophilic granulomatosis with polyangiitis (EGPA), allergic granulomatous angiitis)
  - and other auto-immune disorders
- There are also non-autoimmune causes, most of which are immune-mediated reactions to infections.
The lung manifestations are various and may include: hypoxemia, pulmonary hemorrhage, infiltrates
The renal manifestations are various and may include: renal failure (acute or subacute or even chronic), hematuria

	What is the main part of this, before the "also"? Is it "Code the underlying condition"?

ALSO code the manifesting symptoms as Combined ICD10 codes; for example this might be Hemorrhage, respiratory sites, NOS AND Nephritic syndrome, rapidly progressive
if the cause (likely one of the conditions listed above) is known, list its code as the same Combined ICD10 codes as the symptoms
if the cause is not known by the end of the ward stay, then as usual, code the manifestations, which may be signs or symptoms