PM – Rheumatology

The potential of the synovial inflammation to is the hallmark of the disease

Scleroderma (systemic sclerosis) is a chronic autoimmune connective tissue disorder characterized by excessive collagen deposition in the skin and internal organs.

Dysphagia: Common due to esophageal smooth muscle fibrosis and hypomotility.

Raynaud’s phenomenon: Very common, often an initial symptom.

Skin contracture: Results from skin thickening and fibrosis.

Calcification in all the long bones: Not a feature. While calcinosis cutis (localized calcium deposits in skin/subcutaneous tissue) can occur, generalized calcification of all long bones is not seen.

A “mosaic pattern of cement lines” typically refers to a histological appearance found in bone tissue affected by Paget‘s disease. This pattern is characterized by the presence of thick, irregularly shaped cement lines (also called cementum) that divide the bone into a mosaic-like structure. These lines demarcate randomly oriented lamellar bone, giving the tissue a disorganized and abnormal appearance

The Pathergy test is a diagnostic skin hyperreactivity test where a sterile needle prick leads to a papule or pustule formation within 24–48 hours.

It is highly specific for Behçet’s syndrome, which is a multisystem vasculitis characterized by recurrent oral and genital ulcers, uveitis, and skin lesions.

The phenomenon occurs due to exaggerated neutrophil-mediated inflammation.

Raynaud’s disease (primary Raynaud’s phenomenon) is an idiopathic vasospastic disorder that affects small arteries, usually of the fingers and toes.

It is more common in women, especially between ages 15–45 years.

Cold exposure or emotional stress precipitates vasoconstriction, leading to triphasic color change (white–blue–red).

Lower extremity involvement can occur but is usually asymmetrical or much less common compared to upper extremities; symmetrical lower limb involvement is not typical for primary Raynaud’s.

In primary gout, about 90% of cases are due to underexcretion of uric acid, not overproduction. Overproduction accounts for only ~10%.

Serum uric acid levels may be normal during an acute attack because the urate crystals are deposited in joints and soft tissues rather than circulating.

Gout has a male predominance (Male : Female ≈ 9:1 before menopause).

Definitive diagnosis is made by demonstrating negatively birefringent monosodium urate crystals in synovial fluid aspirate under polarized light microscopy.

Clubbing of a single digit may follow trauma, in tophaceous gout and sarcoidosis. With advanced
lung disease, clubbing of digits appears in virtually all patients with CF

Psoriatic arthritis is a chronic inflammatory arthropathy associated with psoriasis, showing diverse clinical patterns.

Involves distal joints of hand and foot: The distal interphalangeal (DIP) joints are characteristically involved, especially in the DIP-predominant subtype.

Pencil-in-cup deformity: Radiographic hallmark caused by erosion of the phalangeal head and expansion of the base of the adjacent bone.

Sacroiliitis: May be unilateral or bilateral, part of the spondyloarthropathy spectrum.

Osteoarthritis (OA) commonly involves weight-bearing joints (knee, hip, spine) and joints subjected to repetitive stress (first carpometacarpal joint of thumb).

Knee joint is the most commonly affected, followed by hip joint and first CMC joint.

Metacarpophalangeal (MCP) joints are rarely affected in primary OA — they are more commonly involved in rheumatoid arthritis.

Therefore, among the listed options, MCP joint involvement is the least common in OA.

Rheumatoid arthritis (RA): Classically causes marginal joint erosions due to pannus formation and synovial inflammation.

Psoriatic arthritis: Can cause erosive changes, especially in DIP joints (“pencil-in-cup” deformity).

Multicentric reticulohistiocytosis: Rare systemic disorder causing severe erosive polyarthritis along with skin lesions.

Systemic lupus erythematosus (SLE): Typically causes non-erosive arthritis despite marked joint pain and swelling. This is due to immune complex–mediated synovitis without pannus formation, leading to deformities (Jaccoud arthropathy) but without bone destruction.

Sicca syndrome refers to the triad of xerostomia (dry mouth), xerophthalmia (dry eyes), and sometimes dryness of other mucosal surfaces, usually due to autoimmune destruction of exocrine glands. It may occur as:

Primary Sjögren’s syndrome – isolated form.

Secondary Sjögren’s syndrome – associated with other autoimmune/connective tissue disorders.Common associations:

Rheumatoid arthritis ✅

Systemic sclerosis (scleroderma) ✅

Systemic lupus erythematosus ✅

Chronic active hepatitis (autoimmune hepatitis) ✅

Midline granuloma (now known as extranodal NK/T-cell lymphoma, nasal type) is not associated with Sicca syndrome — it is a destructive lesion of the nasal cavity, unrelated to autoimmune exocrinopathy.

C-ANCA (cytoplasmic antineutrophil cytoplasmic antibodies) are most strongly associated with Wegener’s granulomatosis, now called Granulomatosis with polyangiitis (GPA). The target antigen is proteinase 3 (PR3).

Wegener’s granulomatosis (GPA) – Strong C-ANCA positivity ✅

Microscopic polyangiitis – More often p-ANCA (MPO) positive

Churg-Strauss syndrome (Eosinophilic granulomatosis with polyangiitis) – Usually p-ANCA

Polyarteritis nodosa (PAN) – Typically ANCA-negative

Kawasaki disease (mucocutaneous lymph node syndrome) is an acute, self-limited vasculitis of medium-sized arteries, predominantly affecting children younger than 5 years.

Classical features (per AHA criteria) include:

Fever lasting at least 5 days (mandatory criterion)

Bilateral non-exudative conjunctivitis

Changes in lips and oral cavity – erythema, strawberry tongue, cracked lips

Polymorphous rash or erythema

Cervical lymphadenopathy – usually unilateral and in the anterior cervical region, with nodes at least 1.5 cm in diameter

Changes in extremities – erythema, edema, periungual desquamation

Thrombocytosis is common in the subacute phase, not thrombocytopenia.

Diseases and genetic risk factors that are shared with IBD include rheumatoid arthritis (TNFAIP3),
psoriasis (IL23R,IL12B), ankylosing spondylitis (IL23R), type 1 diabetes mellitus (IL10,PTPN2),
asthma (ORMDL3), and systemic lupus erythematosus (TNFAIP3,IL10).

Poncet’s disease is a reactive symmetric form of polyarthritis that affects persons with visceral
or disseminated tuberculosis. No mycobacteria are found in the joints, and symptoms resolve with
antituberculous therapy.

Felty’s syndrome consists of chronic RA, splenomegaly, neutropenia, anemia & thrombocytopenia.

Classic triad of cryoglobulinemic syndrome consists of purpura, arthralgias & weakness. Others are
glomerulonephritis, peripheral neuropathy, generalized vasculitis, livedo reticularis, ischemic ulcers,
acrocyanosis and hemorrhagic bullae.

CREST syndrome includes Calcinosis, Raynaud’s phenomenon, Esophageal involvement,
Sclerodactyly, and Telangiectasia.

Beryllium is commonly associated with a chronic granulomatous inflammatory disease that is similar to sarcoidosis. Hilar adenopathy is less common though.

Iridocyclitis is a feature of Behçet’s syndrome

Rheumatoid factor testing suffers from low specificity, since it can be detected in bacterial
endocarditis, malaria, tuberculosis, osteomyelitis, hepatitis C (with or without cryoglobulinemia),
SjÖgren syndrome, systemic lupus erythematosus, primary biliary cirrhosis, postvaccination
arthropathy, and aging.

Primary vasculitis syndromes include Wegener’s granulomatosis, Churg-Strauss syndrome,
Henoch-Schönlein purpura, Polyarteritis nodosa, Microscopic polyangiitis, Giant cell arteritis,
Takayasu’s arteritis, Idiopathic cutaneous vasculitis, Essential mixed cryoglobulinemia, Behçet’s
syndrome, Isolated vasculitis of CNS, Cogan’s syndrome & Kawasaki disease.

The patient is a coal mine worker, which raises suspicion for pneumoconiosis.

Caplan’s syndrome is characterized by the association of rheumatoid arthritis with pneumoconiosis (most commonly coal worker’s pneumoconiosis or silicosis), producing multiple well-defined nodules (0.5–5 cm) in both lungs.

These nodules may cavitate and often show central calcification.

The combination of exposure history, pulmonary nodules, and rheumatoid features (joint pain) strongly supports this diagnosis.

“String of beads” appearance on angiography is characteristic of fibromuscular dysplasia caused by
thickened fibromuscular ridges contiguous with thin, less-involved portions of the arterial wall.

Rheumatoid arthritis (RA) primarily affects synovial joints, and in the spine, it most often involves the cervical spine, particularly the atlantoaxial (C1–C2) joint.

Involvement leads to atlantoaxial subluxation, which can cause spinal cord compression if severe.

Lumbar, thoracic, and sacral regions are rarely involved in RA, as the disease favors joints with abundant synovium, and these areas have less or no typical synovial joints.