Side of involvement and areas of segmental distribution | Right side involving: Shoulder, chest, abdomen, retroauricular, and intraauricular | Face and trunk | Left side involving: retroauricular, scapular, pectoralis major, and lumbar regions | Right side involving: arm and leg | Twin spot phenomenon involving: back | N/A | N/A | Twin spot phenomenon | Left side involving: head, neck, trunk, and extremities |