Cold-Triggered Digital Vasospasm
Cold or stress triggers a tri-phasic color change in the fingers.
- 3–5%: General population prevalence (varies by climate)
- ~4:1: Female-to-male ratio (primary form)
- 3 phases: Classic color sequence (white, blue, red)
- 15–20 min: Typical attack duration (per episode)
The vasospastic sequence
Digital arterioles spasm, then relax in a set order.
Pallor, cyanosis, rubor is the classic triad.
Primary vs secondary at first glance
Both share the trigger; downstream findings diverge.
Why differentiation matters
Secondary Raynaud's can herald serious systemic disease.
Age of Onset as a Screening Clue
Onset before 30 favors primary; after 30 favors secondary.
- <30 yo: Primary typical onset (often teens–20s)
- >30 yo: Secondary typical onset (new adult-onset flag)
- Benign: Primary lifetime course (rarely progresses)
- Scleroderma+: Secondary association (connective tissue disease)
Why age matters
Late-onset attacks warrant a broader autoimmune workup.
New onset after 30 is a screening red flag.
Primary onset pattern
Young patients, gradual onset, stable over decades.
Secondary onset pattern
Older onset often precedes overt autoimmune disease.
Bilateral Symmetry of Attacks
Primary attacks are symmetric; secondary attacks are often patchy.
- Bilateral: Primary symmetry (both hands equally)
- Asymmetric: Secondary symmetry (single digits spared/hit)
- Thumb: Digits usually spared (primary) (often unaffected)
- Common: Secondary single-digit onset (may start unilateral)
Reading the pattern
Compare left vs right hand digit-by-digit involvement.
Asymmetric or single-digit attacks suggest secondary disease.
Symmetric baseline
Primary disease affects fingers evenly on both hands.
Patchy involvement
Vascular or immune damage explains asymmetric secondary attacks.
Ulcers, Capillaries, and Autoantibodies
Three red flags strongly point toward secondary disease.
- Flag 1: Digital ulcers (tissue ischemia/necrosis)
- Flag 2: Abnormal nailfold capillaries (dropout, giant loops)
- Flag 3: Positive ANA / autoantibodies (scleroderma-spectrum markers)
- Refer: Any flag present (rheumatology workup)
Digital ulcers
Fingertip ulceration signals fixed vascular or tissue damage.
Ulcers essentially exclude a primary diagnosis.
Nailfold capillaroscopy
Dropout and giant capillaries mark microvascular disease.
Serology
Positive ANA raises pretest probability of connective tissue disease.
Classification Guides Management
Combined findings sort patients into two very different pathways.
- Conservative: Primary management (reassurance, warmth, avoid triggers)
- Workup: Secondary management (rheumatology + serology + capillaroscopy)
- Excellent: Primary prognosis (no organ threat)
- Disease-driven: Secondary prognosis (depends on underlying cause)
Primary pathway
Reassure, recommend warmth and trigger avoidance, monitor.
Most primary patients need no medication at all.
Secondary pathway
Refer for autoimmune workup and vascular protection.
Longitudinal watch
Reclassification can occur if new red flags appear.