From the Guidelines
Psoriatic arthritis in the hands is a chronic inflammatory condition characterized by swelling, pain, stiffness, and warmth in the affected joints, often involving the distal interphalangeal joints, and can lead to joint deformity and nail changes if left untreated. The condition typically presents with a distinctive pattern of joint involvement, including dactylitis, or "sausage digits," where an entire finger becomes swollen, and morning stiffness lasting more than 30 minutes is common 1. Patients may experience characteristic nail changes, including pitting, ridging, and separation from the nail bed. Unlike rheumatoid arthritis, psoriatic arthritis often affects joints asymmetrically and may spare the small joints of the hands entirely in some patients.
Key Characteristics
- Swelling, pain, stiffness, and warmth in the affected joints
- Distal interphalangeal joints are commonly affected
- Dactylitis, or "sausage digits," where an entire finger becomes swollen
- Morning stiffness lasting more than 30 minutes is common
- Characteristic nail changes, including pitting, ridging, and separation from the nail bed
Management
Early diagnosis and treatment with disease-modifying antirheumatic drugs (DMARDs) like methotrexate, or biologics such as TNF inhibitors, IL-17 inhibitors, or IL-23 inhibitors, can prevent permanent joint damage and maintain hand function 1. Physical therapy and occupational therapy are also important components of management to preserve joint mobility and hand strength. According to the 2018 American College of Rheumatology/National Psoriasis Foundation guideline for the treatment of psoriatic arthritis, the treatment approach should be individualized based on the patient's specific needs and circumstances 1.
Prognosis
If left untreated, psoriatic arthritis can lead to joint deformity, particularly a telescoping appearance called "pencil-in-cup" deformity visible on X-rays, and can have a significant impact on quality of life 1. However, with early diagnosis and treatment, it is possible to prevent permanent joint damage and maintain hand function, improving overall morbidity, mortality, and quality of life outcomes 1.
From the FDA Drug Label
The safety and efficacy of Enbrel were assessed in a randomized, double-blind, placebo-controlled study in 205 patients with PsA Patients were between 18 and 70 years of age and had active PsA (≥ 3 swollen joints and ≥ 3 tender joints) in one or more of the following forms: (1) distal interphalangeal (DIP) involvement (N = 104); (2) polyarticular arthritis (absence of rheumatoid nodules and presence of psoriasis; N = 173); (3) arthritis mutilans (N = 3); (4) asymmetric psoriatic arthritis (N = 81); or (5) ankylosing spondylitis-like (N = 7). Radiographs of hands and wrists were obtained at baseline and months 6,12, and 24. A modified Total Sharp Score (TSS), which included distal interphalangeal joints (i.e., not identical to the modified TSS used for RA) was used by readers blinded to treatment group to assess the radiographs. Some radiographic features specific to PsA (e.g. pencil-and-cup deformity, joint space widening, gross osteolysis, and ankylosis) were included in the scoring system, but others (e.
The characteristics of psoriatic arthritis in the hands include:
- Distal interphalangeal (DIP) involvement
- Polyarticular arthritis
- Arthritis mutilans
- Asymmetric psoriatic arthritis
- Ankylosing spondylitis-like
- Radiographic features such as:
- Pencil-and-cup deformity
- Joint space widening
- Gross osteolysis
- Ankylosis These characteristics were observed in a study of 205 patients with PsA, including 104 with DIP involvement 2.
From the Research
Characteristics of Psoriatic Arthritis in the Hands
- Psoriatic arthritis is a polyarthropathy distinct from rheumatoid arthritis, associated with onychodystrophy and skin lesions 3
- Patients present with stiffness, flexion and extension contractures, digital swelling, or painful joints 3
- Psoriatic arthritis mutilans is a rapidly progressive osteolysis resulting in severe deformity 3
- Radiographs reveal widened joint spaces with interphalangeal joint destruction, resorption of the distal tufts, and frequently spontaneous fusion 3
Clinical Features
- Digital swelling, such as painless toe dactylitis, may occur occasionally and go unnoticed, leading to diagnostic delay 4
- Non-specific musculoskeletal symptoms and subclinical synovio-entheseal inflammation may characterize the progression from psoriasis to psoriatic arthritis 4
Treatment and Management
- Surgery involves mainly salvage procedures to relieve pain or improve position, as the increase in motion obtained usually is limited 3
- Traditional medications have not been effective in preventing the progression of joint damage, but new medications, including biologics, have emerged with the potential to control the inflammation and arrest the progression of joint damage 5