Table 2.

A tabulation of the possible differential diagnoses.

Diagnosis	Clinical signs and symptoms
Pachydermodactyly	No pain, swelling, tenderness, loss of range of motion. Does not itch generally and bilateral involvement.
Inflammatory arthritis: Psoriatic arthritis, Rheumatoid arthritis (RA), Juvenile idiopathic arthritis	Pain, tenderness, decreased range of motion.
Mechanical etiology: Osteoarthritis	Pain, decreased range of motion, stiffness.
Knuckle pads/Garrod's pads	Skin-colored subcutaneous nodules.
Pseudoknuckle pads	Similar to knuckle pads.
Lichen Simplex Chronicus	Usually itchy with only slight swelling present.
Self-healing juvenile cutaneous mucinosis	Papules on various parts of the body.
Early systemic sclerosis	Diffuse swelling of digits. Late cases show ulceration and telangiectasias.
Dermatomyositis	Inflammatory papules of scaly appearance.
Acanthosis nigricans	Plaques that have a hyperpigmented, velvety appearance.
Thiemann's disease	Shortening of affected PIP joints with shortening of digits. Pain may be present.
Systemic Lupus Erythematosus Dermatitis	Erythema, dorsal involvement of the digits with sparing of the knuckles.
Mixed Connective Tissue Disease	Digits of the hand appear swollen or sclerosed with evidence of Raynaud's phenomenon and arthritis. Cutaneous lesions might also be present.
Referred pain due to cervical spondylosis	Pain in the neck can spread to the hands as well. Additionally, weakness and numbness of the hands may also be present.
Benign tumors such as fibromas	Presentation may vary.
Tuberous sclerosis	Swelling.
Primary pachydermoperiostosis (Touraine-Solente-Golé syndrome)	Periarticular tissue proliferation with clubbing evident.