Systemic connective tissue disorders

M31.10 identifies thrombotic microangiopathy (TMA) when the specific subtype or underlying cause has not been documented or determined. It is the unspecified fallback within the M31.1 category when neither HSCT-TMA (M31.11) nor another defined TMA variant (M31.19) applies.

M31.11 identifies thrombotic microangiopathy that arises as a direct complication of hematopoietic stem cell transplantation (HSCT), a distinct clinical entity from other TMA subtypes.

M31.19 classifies thrombotic microangiopathies that don't fall under hematopoietic stem cell transplantation-associated TMA (M31.11) or the unspecified category (M31.10) — most notably serving as the designated code for thrombotic thrombocytopenic purpura (TTP).

Granulomatosis with polyangiitis (GPA) confirmed in the absence of renal involvement — necrotizing granulomatous vasculitis affecting the respiratory tract and other systems, with kidneys explicitly spared or not yet implicated.

Granulomatosis with polyangiitis (GPA/Wegener's) with confirmed renal involvement, such as glomerulonephritis — the more severe phenotype within the M31.3 subcategory.

SLE confirmed to involve at least one organ or body system, but the specific organ or system affected has not yet been identified or documented in the medical record.

M32.11 identifies endocarditis occurring as a direct manifestation of systemic lupus erythematosus (SLE), also called Libman-Sacks disease — the nonbacterial verrucous endocarditis characteristic of SLE.

Pericarditis occurring as a direct manifestation of systemic lupus erythematosus, classified under SLE with organ or system involvement (parent M32.1).

M32.13 identifies documented pulmonary manifestations arising directly from systemic lupus erythematosus, classifying the lung as the specifically involved organ within the broader M32.1 organ-involvement subcategory.

M32.14 identifies glomerular disease — including lupus nephritis — occurring as a direct manifestation of systemic lupus erythematosus (SLE), classified under SLE with organ or system involvement.

M32.15 identifies tubulo-interstitial nephropathy as the specific renal manifestation of systemic lupus erythematosus — distinct from glomerular disease — affecting the renal tubules and surrounding interstitium in the setting of confirmed SLE.

M32.19 captures systemic lupus erythematosus with documented involvement of an organ or system not individually named in codes M32.11–M32.15 — covering manifestations such as neuropsychiatric (lupus encephalitis), musculoskeletal, hematologic, dermatologic, hepatic, or ocular involvement when those specific sites lack a dedicated subcategory.

Juvenile dermatomyositis in a pediatric patient where the extent or type of organ involvement has not been specified in the clinical documentation.

M33.01 identifies juvenile dermatomyositis in a patient under age 18 where the disease has extended to involve the respiratory system, such as interstitial lung disease, aspiration pneumonia, or respiratory muscle weakness.

M33.02 identifies juvenile dermatomyositis in a pediatric patient where documented muscle weakness or muscle enzyme elevation confirms myopathy as a concurrent manifestation of the inflammatory condition.

Juvenile dermatomyositis presenting with characteristic skin findings (heliotrope rash, Gottron papules) but without clinically detectable muscle weakness or inflammatory myopathy — also termed amyopathic juvenile dermatomyositis.

Juvenile dermatomyositis (JDM) presenting with documented involvement of an organ system other than the respiratory tract or skeletal muscle — the two organ manifestations captured by sibling codes M33.01 and M33.02.

M33.10 classifies adult dermatomyositis — a systemic inflammatory disease affecting skin and skeletal muscle — when the provider has confirmed the diagnosis but has not documented involvement of any specific organ system beyond the index disease.

M33.11 identifies adult-onset or non-juvenile dermatomyositis (classified as 'other' dermatomyositis within category M33.1) that is explicitly complicated by respiratory system involvement, such as interstitial lung disease or inflammatory pulmonary manifestations.

Dermatomyositis (adult-onset, non-juvenile) confirmed with objective myopathy — proximal muscle weakness, elevated creatine kinase, and/or EMG or biopsy findings consistent with inflammatory muscle disease.

M33.13 identifies adult-onset dermatomyositis — a systemic inflammatory disorder classified under 'Other dermatomyositis' — in which the characteristic cutaneous manifestations (heliotrope rash, Gottron's papules, mechanic's hands) are present but documented muscle inflammation or clinical myopathy is absent at the time of coding.

Other dermatomyositis (non-juvenile, adult-onset) with documented involvement of an organ system other than the respiratory tract or musculature — such as cardiac, gastrointestinal, or cutaneous visceral complications.

Polymyositis with organ involvement that has not been specified in the clinical documentation — used when the treating provider has established a polymyositis diagnosis but has not documented which organ system beyond skeletal muscle is affected.

Polymyositis with documented respiratory involvement, such as interstitial lung disease or pulmonary compromise — use when both the inflammatory myopathy and the pulmonary manifestation are confirmed and charted.

Polymyositis with confirmed muscle involvement (myopathy), classified under the dermatopolymyositis category of systemic connective tissue disorders.

Polymyositis with documented involvement of an organ system other than the respiratory tract or skeletal muscle — such as cardiac or gastrointestinal involvement.

M33.90 identifies dermatopolymyositis that is unspecified as to subtype (juvenile, adult, or polymyositis) and with no documented organ system involvement recorded.

M33.91 identifies dermatopolymyositis of unspecified subtype that is documented with respiratory system involvement, such as interstitial lung disease or inflammatory myopathy-associated lung complications.

Dermatopolymyositis, unspecified type, with documented muscle involvement (myopathy). Use when the clinician has not distinguished between juvenile dermatomyositis, adult/other dermatomyositis, or polymyositis, but has confirmed myopathic manifestations.

M33.93 captures dermatopolymyositis of unspecified type where muscle disease (myopathy) is explicitly documented as absent — the inflammatory skin findings are present but without objective muscle involvement.

M33.99 identifies dermatopolymyositis of unspecified type accompanied by organ involvement that is neither respiratory nor limited to myopathy — a catch-all for systemic manifestations such as cardiac, gastrointestinal, or renal involvement when the subtype (juvenile vs. adult-onset) is not documented.

M34.81 identifies systemic sclerosis (scleroderma) in which the disease process has extended to involve the lungs — most commonly as interstitial lung disease or pulmonary arterial hypertension — as a documented manifestation of the underlying connective tissue disorder.

Systemic sclerosis (scleroderma) presenting with concurrent inflammatory or fibrotic muscle disease (myopathy) as a documented manifestation.

M34.83 identifies systemic sclerosis (scleroderma) complicated by polyneuropathy — diffuse peripheral nerve damage occurring as a direct manifestation of the underlying connective tissue disease.

Systemic sclerosis (scleroderma) that does not fit the specifically enumerated subtypes under M34.8 — not lung involvement (M34.81), myopathy (M34.82), or polyneuropathy (M34.83) — and is not progressive systemic sclerosis (M34.0), CREST syndrome (M34.1), or drug/chemical-induced (M34.2).

M35.00 identifies Sjögren syndrome where the documentation does not specify any associated organ or system manifestation — the default code when the clinical picture is confirmed Sjögren's but no organ-specific subtype is documented.

Sjögren syndrome with keratoconjunctivitis sicca — the specific subcode for Sjögren-related dry eye and corneal inflammation confirmed as autoimmune in etiology.

Sjögren syndrome with documented pulmonary manifestations, classified under systemic connective tissue disorders in ICD-10-CM Chapter 13.

Sjögren syndrome with documented skeletal muscle involvement (myopathy), classified under systemic connective tissue disorders in ICD-10-CM Chapter 13.

Sjögren syndrome with renal tubulo-interstitial involvement, capturing the specific manifestation of tubulointerstitial nephropathy — including renal tubular acidosis — as a direct complication of the systemic autoimmune disease.

Sjögren syndrome presenting with inflammatory arthritis as a documented systemic manifestation, classified under the M35.0 Sjögren syndrome family of codes.

M35.06 identifies Sjögren syndrome in which the autoimmune process has extended to involve the peripheral nervous system, such as sensory neuropathy, sensorimotor polyneuropathy, or autonomic neuropathy, as a documented systemic manifestation.

Sjögren syndrome with documented involvement of the central nervous system, including brain, spinal cord, or meninges manifestations attributable to the underlying autoimmune disease.

Sjögren syndrome presenting with documented gastrointestinal tract involvement, classified under systemic connective tissue disorders (M35.0x family).

M35.09 captures Sjögren syndrome when the organ involvement doesn't match any of the more specific M35.0x codes — a true residual category for documented systemic manifestations outside the named subcategories.

Sjögren syndrome with documented glomerular disease as a systemic manifestation — a specific subset of M35.0 reserved for cases where renal glomerular involvement is clinically established.

M35.0B identifies Sjögren syndrome in which vasculitis — inflammation of blood vessel walls — has been documented as an associated systemic manifestation of the underlying autoimmune disease.

M35.0C identifies Sjögren syndrome when the documented manifestation is dental involvement — specifically the oral and salivary gland effects of this systemic autoimmune condition, such as xerostomia-driven rampant caries, salivary gland dysfunction, or parotid enlargement.

M35.81 classifies multisystem inflammatory syndrome (MIS) — a serious, hyperinflammatory condition affecting multiple organ systems, seen in both children (MIS-C) and adults (MIS-A), and strongly associated with prior SARS-CoV-2 infection.

M35.89 captures systemic connective tissue disorders that are definitively diagnosed but do not fit any more specific code in the M30–M36 range — a true 'other specified' bucket for conditions such as eosinophilia-myalgia syndrome and collagen vascular disease NOS.

M30.0 identifies classic polyarteritis nodosa (PAN), a systemic necrotizing vasculitis affecting medium-sized muscular arteries, distinct from microscopic polyangiitis and other related vasculitides.

Systemic necrotizing vasculitis with granuloma formation and obligate pulmonary involvement, corresponding to eosinophilic granulomatosis with polyangiitis (EGPA), formerly called Churg-Strauss syndrome.

M30.2 classifies juvenile polyarteritis — a pediatric-onset necrotizing vasculitis of medium-sized arteries that mirrors polyarteritis nodosa (M30.0) but occurs in children and adolescents.

M30.3 identifies Kawasaki disease — an acute systemic vasculitis affecting medium-sized arteries, classified under polyarteritis nodosa and related conditions in the musculoskeletal and connective tissue chapter.

M30.8 captures conditions that fall within the polyarteritis nodosa family but don't fit the more specific subcategories under M30 — its primary 'Applicable To' entry is polyangiitis overlap syndrome.

M31.0 classifies hypersensitivity angiitis, an immune-mediated necrotizing vasculopathy of small vessels, and explicitly includes Goodpasture's syndrome (anti-glomerular basement membrane disease) as an applicable condition under this code.

M31.2 classifies lethal midline granuloma, a rare and destructive necrotizing vasculopathy characterized by progressive inflammation, ulceration, and tissue destruction centered on the midline facial structures — primarily the nose, sinuses, and hard palate.

Chronic granulomatous large-vessel vasculitis targeting the aorta and its primary branches, producing progressive stenosis, occlusion, and aneurysm formation — classified under ICD-10-CM as Takayasu arteritis (aortic arch syndrome).

M31.5 identifies giant cell arteritis (GCA) occurring concurrently with polymyalgia rheumatica (PMR) — a combined presentation requiring documentation of both conditions to justify this code over M31.6.

Giant cell arteritis (GCA) without concurrent polymyalgia rheumatica — a granulomatous large-vessel vasculitis affecting the aorta and its branches, most commonly the temporal and cranial arteries, in patients typically aged 50 or older.