Rare diseases · Sign or symptom
Swan neck-like deformities of the fingers
HP:0006150
What it means
A swan neck deformity describes a finger with a hyperextended PIP joint and a flexed DIP joint. The most common cause for a swan neck-like deformity is a disruption of the end of the extensor tendon. Conditions that loosen the PIP joint and allow it to hyperextend, for example conditions that weaken the volar plate, can produce a swan neck deformity of the finger. One example is rheumatoid arthritis. Another cause are conditions that tighten up the small (intrinsic) muscles of the hand and fingers, for example hand trauma or nerve disorders, such as cerebral palsy, Parkinson's disease, or stroke.
Rare diseases that can present with this1
The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions. A sign on this page is a conversation to have with a clinician, not a conclusion.
Part of the broader category
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Start free with EleplanThis page uses the Human Phenotype Ontology (2026-06-23) — Human Phenotype Ontology Consortium, hpo.jax.org. Disease associations from Orphanet (INSERM), CC BY 4.0. Content is educational and is not medical advice.