Arthritis of the Fingers Explained

Описание: Arthritis of the fingers. Diagnosing arthritis of the fingers can be difficult. Arthritis can affect any joint in the body, but it is commonly seen in the joints of the fingers. These are the different types of arthritis and their pattern of joint involvement: Osteoarthritis, Psoriatic Arthritis, Gouty Arthritis, and Rheumatoid Arthritis.

Osteoarthritis of the fingers is characterized by Heberden's nodes. Heberden's nodes are hard or bony swellings that develop in the distal interphalangeal (DIP) joints. They may or may not be painful. These nodes are caused by the formation of osteophytes due to repeated trauma at the joint and usually appear in middle age.

Bouchard's nodes are bony growths that form on the proximal interphalangeal (PIP) joints of the fingers. Like Heberden’s nodes, Bouchard's nodes may or may not be painful and are typically associated with limited motion of the affected joint.

Mucous cysts are small fluid-filled sacs that form between the DIP joint and the base of the fingernail. The best treatment for mucous cysts is surgical excision of the cyst and removal of the underlying osteophyte to reduce the risk of recurrence.

Psoriatic arthritis is an inflammatory type of arthritis and can sometimes be mistaken for osteoarthritis. Psoriatic arthritis includes dactylitis, also known as “sausage digit,” which is inflammation of the entire finger. The sausage digit is a major clinical feature of psoriatic arthritis.

Nail pitting—small depressions in the fingernails—is commonly seen in patients with psoriasis.

Gouty arthritis is a form of inflammatory arthritis, also referred to as gout. Gouty arthritis may mimic infection and typically develops in patients with elevated serum uric acid. Uric acid forms needle-like crystals in the joint, causing pain, tenderness, swelling, and tenosynovitis. X-rays may reveal periarticular erosions, which are often multiple, bilateral, and have sclerotic borders.

Rheumatoid arthritis
Juvenile rheumatoid arthritis: Antinuclear antibodies are positive in approximately 30% of cases. Rheumatoid factor is typically negative in children but may become positive later. Affected children may present with shortened digits. The normal joint appears unaffected, while the affected joint demonstrates a swollen, inflamed synovial membrane.

Polyarticular juvenile rheumatoid arthritis is a subtype that affects five or more joints, accounting for about 30% of cases.

Pauciarticular-onset juvenile idiopathic arthritis involves fewer than five joints and constitutes about 50% of cases. In this type, the iris of the eye should be examined for iridocyclitis.

In polyarticular rheumatoid arthritis, the cervical spine must be evaluated for subaxial instability.

Rheumatoid arthritis of the hand occurs more commonly in females. It features spontaneous remissions and exacerbations and may present systemically. The disease is typically polyarticular, bilateral, and symmetrical, with predominant involvement of the hands and feet.

Patients often report joint pain and stiffness, especially in the morning. Morning stiffness is a hallmark symptom. Radiographs show periarticular erosions at diagnosis. Osteopenia and minimal osteophyte formation favor the diagnosis of rheumatoid arthritis.

Stages of rheumatoid arthritis in the hand:

Early/acute stage: Hot, swollen, and tender joints due to synovitis. This may involve the wrist or MCP joints and can present with flexor tenosynovitis.
The disease may be complicated by digital vasculitis, ecchymosis, skin atrophy, and rheumatoid nodules.
Advanced disease: Swelling of the MCP joints, lateral displacement of the extensor tendons, tendon ruptures, and ulnar deviation of the fingers.
Radiographs reveal MCP joint destruction with subluxation, ulnar deviation, and wrist destruction.
Finger deformities include mallet finger, boutonnière deformity, and swan neck deformity. The thumb may also be involved. These deformities are caused by proliferation, inflammation, and hypertrophy of the synovium.

Involvement of the distal radioulnar joint is commonly associated with rupture of the extensor digiti minimi tendon.
QUIZZES
1. Which joints are affected by Heberden's nodes?
Correct Answer: Distal interphalangeal joints (DIP)
A) Proximal interphalangeal joints (PIP)
B) Metacarpophalangeal joints (MCP)
C) Distal interphalangeal joints (DIP)
D) Carpometacarpal joint
Explanation: Heberden's nodes occur at the DIP joints, typical of osteoarthritis.
2. What is the hallmark sign of psoriatic arthritis in the fingers?
Correct Answer: Dactylitis (sausage digit)
A) Heberden’s nodes
B) Mallet finger
C) Dactylitis (sausage digit)
D) Swan neck deformity
Explanation: Dactylitis involves inflammation of an entire digit, classic in psoriatic arthritis.
3) Bouchard’s nodes are found in which joints?
Correct Answer: A)Proximal interphalangeal joints (PIP)