CMTC is a disorder that is present at birth and is characterized by discolored patches of skin caused by dilated blood vessels (livedoreticulartelangiectases). These dilated vessels cause the skin to have a marbled or fishnet appearance (cutis mamorata). Severe CMTC can create ulcerations in the affected skin area of the dilated blood vessels. CTMC tends to affect the arms, legs, and trunk. Facial involvement if rare with CMTC. While the cause of CMTC is unknown, it is believed it is due to genetic mosaicism or inappropriate capillary contraction.