Rheumatoid nodules

Introduction Extra-articular manifestations of rheumatoid arthritis, the nodule center is a non-structural substance of celluloid necrotic tissue and immune complexes containing IGG, surrounded by fibroblasts, peripherally infiltrating mononuclear, lymphoid and plasma cells, forming a typical Granulation tissue. Rheumatoid nodules often occur under the skin under pressure, which is a typical proliferative lesion outside the joint. A rheumatoid nodule is a hard, round or elliptical knot. Clinically, there are two types of superficial nodules and deep nodules. Adjusting eating habits and keeping warm can play an important role in the prevention of rheumatoid arthritis.

Cause

Rheumatoid nodules often occur under the skin under pressure, which is a typical proliferative lesion outside the joint. In the past, rheumatoid nodules were thought to be composed of a central necrotic layer surrounded by inflammatory cells and collagenous tissue, and a monolayer infiltrating around the outer blood vessels.

However, it was observed under an electron microscope that the rheumatoid nodules consisted of five layers:

1 necrotic center: composed of inflammatory cells and cellulose.

2 types of cellulose layer.

3 macrophage layer.

4 monocyte layer.

5 The outermost blood vessels are surrounded by immune complex deposition and chronic inflammation. The role of rheumatoid nodules in the pathogenesis and pathogenesis of RA is unclear. However, it often appears at the same time as a serious RA, which has attracted people's attention.

an examination

Related inspection

Rheumatoid factor (RF) anti-hemolytic streptococcus "O" test anti-cyclic citrullinated peptide antibody (anti-CCP) C-reactive protein test (CRP)

Rheumatoid nodules: more common in the joints of the joints and often under pressure, no obvious tenderness, not easy to move. Rheumatoid nodules can also occur in the internal organs, pericardial surface, endocardium, central nervous system, lung tissue and sclera.

1. Regular inspection:

(1) Blood routine: About 30% of patients with rheumatoid arthritis have anemia, mostly positive cell anemia. Platelet elevation during the active period of the disease. In a few cases, there is a decrease in white blood cells, such as Felty syndrome.

(2) Acute phase reactants: Most patients with rheumatoid arthritis have an increased erythrocyte sedimentation rate and elevated C-reactive protein during the active phase, and return to normal when the condition is relieved.

2. Autoantibodies:

(1) Rheumatoid factor (RF): 75% to 85% of patients are positive for serum rheumatoid factor and are associated with disease and extra-articular manifestations.

(2) Anti-citrullinated protein antibody (ACPA): Anti-citrullinated protein antibody is a generic term for autoantibodies containing citrullinated epitopes, and is highly sensitive and specific for the diagnosis of rheumatoid arthritis. Sexuality and is closely related to the condition and prognosis of rheumatoid arthritis.

Differential diagnosis

Joint performance

Rheumatoid arthritis affects joint symptoms of symmetry, persistent joint swelling and pain, often accompanied by morning stiffness. The affected joints are most common in the proximal interphalangeal joint, metacarpophalangeal joint, wrist, elbow and toe joint; at the same time, the cervical vertebrae, temporomandibular joint, chest lock and acromioclavicular joint can also be affected. In the middle and late stages, the "swan neck" of the finger (Fig. 1) and the "button flower" (Fig. 2) may be deformed, the joint stiffness and the metacarpophalangeal joint are subluxated, and the metacarpophalangeal joint is skewed to the ulnar side.

Extra-articular manifestation

1. Rheumatoid nodules: more common in the joints of the joints and often under pressure, no obvious tenderness, not easy to move. Rheumatoid nodules can also occur in the internal organs, pericardial surface, endocardium, central nervous system, lung tissue and sclera.

2. Vasculitis: can affect a variety of blood vessels, with more common in the small and medium arteries. Can be expressed as finger gangrene, skin ulcers, peripheral neuropathy, scleritis and so on.

3. Heart: pericarditis, non-specific heart valve inflammation, myocarditis.

4. Pleural and pulmonary: pleurisy, pulmonary interstitial fibrosis, pulmonary rheumatoid nodules, pulmonary hypertension.

5. Kidney: membranous and mesangial proliferative glomerulonephritis, interstitial nephritis, focal glomerulosclerosis, proliferative nephritis, IgA nephropathy and amyloidosis.

6. Nervous system: sensory peripheral neuropathy, mixed peripheral neuropathy, multiple mononeuritis and embedding peripheral neuropathy.

7. Hematopoietic system: Patients with rheumatoid arthritis may have positive cell angiochromatosis and elevated platelets during active disease.

Differential diagnosis

(1) Osteoarthritis: The age of onset is more than 40 years old, mainly involving the weight-bearing joints such as knee and spine. Joint pain is aggravated during exercise, and joint swelling and effusion may occur. Finger osteoarthritis is often misdiagnosed as rheumatoid arthritis, especially when there is a Heberden nodule in the distal interphalangeal joint and a Bouchard nodule in the proximal knuckle. inflammation. ESR in patients with osteoarthritis, C-reactive protein is normal, rheumatoid factor negative or low titer positive. X-ray showed narrow joint space, lip-like hyperplasia or osteophyte formation at the edge of the joint.

(2) Gout: Chronic gouty arthritis is similar to rheumatoid arthritis. Gouty arthritis is more common in middle-aged and elderly men. It is often recurrent. The predilection site is the unilateral first metatarsophalangeal joint or ankle joint. Invasion of knees, ankles, elbows, wrists and hand joints, blood uric acid levels are usually increased in acute attacks, and chronic gouty arthritis can occur in joints and auricles.

(3) psoriatic arthritis: psoriatic arthritis is mainly affected by the distal joints of the fingers or toes, and joint deformities may occur, but rheumatoid factor is negative, and skin or nail lesions with psoriasis are associated.

(4) Ankylosing spondylitis: This disease mainly invades the spine, but the surrounding joints can also be affected, especially those with knee, ankle and hip joints as the first symptom, which needs to be differentiated from rheumatoid arthritis. The disease has the following characteristics: young men are more common; mainly invading the ankle joint and spine, peripheral joint involvement is more common in the lower limbs, asymmetrical joint involvement, often tendonitis; 90% to 95% of patients are HLA-B27 positive; Rheumatoid factor negative; X-ray changes in the ankle and spine are helpful for diagnosis.

(5) Arthritis caused by connective tissue disease: Sjogren's syndrome, systemic lupus erythematosus can have joint symptoms, and some patients are positive for rheumatoid factor, but they all have corresponding characteristic clinical manifestations and autoantibodies.

(6) Other atypical rheumatoid arthritis with a single or minor joint onset should be differentiated from infectious arthritis (including tuberculosis infection), reactive arthritis, and rheumatic fever.

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