Which feature is most characteristic of CREST syndrome?

• A. Calcinosis
• B. Raynaud phenomenon
• C. Esophageal dysmotility
• D. Sclerodactyly

Answer: (B)

CREST syndrome is the limited form of systemic sclerosis, where vascular and fibrotic features overlap. The feature that best captures its hallmark presentation is Raynaud phenomenon. Digital arteries spasm in response to cold or stress, causing the characteristic triphasic color change (white from ischemia, blue from deoxygenation, red from reperfusion) and often painful fingers. This vascular abnormality is very common and typically appears early, serving as a key clue to CREST.

Calcinosis, esophageal dysmotility, and sclerodactyly are indeed part of CREST, but they tend to appear later or vary more among patients. Raynaud phenomenon stands out because of its high prevalence and its position as an early, defining vascular manifestation of the syndrome.