Knuckle pads mimic early psoriatic arthritis

Area of Science:

• Rheumatology
• Dermatology
• Medical Imaging

Background:

• Knuckle pads, also known as Garrod's nodes, are rare, non-inflammatory growths.
• These benign fibro-adipose tissues typically form over the small joints of the hands and feet.
• They are often under-diagnosed and can be mistaken for early signs of arthritis.

Purpose of the Study:

• To highlight the diagnostic challenges associated with knuckle pads.
• To emphasize the importance of differential diagnosis in distinguishing knuckle pads from inflammatory arthritis.
• To present a case where knuckle pads mimicked psoriatic arthritis.

Main Methods:

• Review of clinical presentation and diagnostic imaging.
• Utilizing ultrasound to assess subcutaneous tissue thickening over hand joints.
• Employing dermoscopy to evaluate epidermal and dermal changes.

Main Results:

• Ultrasound effectively identified subcutaneous tissue thickening characteristic of knuckle pads.
• Dermoscopy revealed specific epidermal and dermal changes.
• The case presented demonstrated knuckle pads mimicking psoriatic arthritis, underscoring diagnostic complexity.

Conclusions:

• Accurate differential diagnosis is essential for managing knuckle pads.
• Ultrasound and dermoscopy are valuable tools in assessing knuckle pads.
• Early and correct diagnosis prevents misidentification as inflammatory joint diseases like psoriatic arthritis.