In simple words: CREST syndrome is a type of scleroderma that causes scar-like tissue to grow in place of normal tissue.It can cause calcium deposits, cold and painful fingers and toes, trouble swallowing, and red marks on the skin.

CR(E)ST syndrome is a multisystem connective tissue disorder characterized by the following features: Calcinosis (calcium deposits in the skin), Raynaud's phenomenon (spasm of blood vessels in response to cold or stress), Esophageal dysfunction (difficulty swallowing and acid reflux), Sclerodactyly (thickening and hardening of the skin on the fingers and hands), and Telangiectasia (dilation of capillaries causing red marks on the skin surface).

Example 1: A patient presents with calcium deposits under the skin, Raynaud's phenomenon, and difficulty swallowing. They are diagnosed with CREST syndrome (M34.1)., A patient with known scleroderma develops telangiectasia and sclerodactyly, fulfilling the criteria for CREST syndrome (M34.1)., A patient experiences esophageal dysfunction and Raynaud's phenomenon. Upon further examination, they are found to have calcinosis, leading to a diagnosis of CREST syndrome (M34.1).

Documentation should include medical history, physical exam findings confirming at least two of the five cardinal features (calcinosis, Raynaud's phenomenon, esophageal dysfunction, sclerodactyly, and telangiectasia), and any diagnostic tests performed.