Blaschkos lines, also known as the Lines of Blaschko, are invisible lines that run all along a humans body. Your face, head, back, arms, legs right now, as you read these words are covered with these invisible lines, which come in all sorts of shapes, patterns, and designs. (These are not Halloween costumes – this is as real as it gets.)
Your back, for example, is covered with V shaped lines, much like the one observed in this photo:
Typically, your chest, stomach, and sides have S shaped lines, while your head is covered in wavy patterns of Blaschkos lines. However, some individuals simply have blobs or patches, not lines. Since the lines or blobs are usually invisible, there is no definite way to determine what kind of patterns your Blaschkos lines follow. You just have to hope you have something awesome.
There are skin conditions and disorders that cause the lines to be visible. Again, the actual patterns and lines that become visible can vary greatly. Some individuals have intense cases, so their body actually looks striped like a zebra or tiger. There are others who only have a few spots on their ankle, arm, or shin. (If I had my way, I would have some visible lines. It would be like a tattoo unique just for me.)
No one has yet to figure out why these lines form, or what purpose they serve. Alfred Blaschko, the man that discovered the lines in 1901, proposed that the lines had an embryonic origin, but he could not elaborate any further. He simply discovered them, proved through numerous clinical trials that the lines were there, and then left it for someone else to figure out possibly due to a lack of technical advancement.
If you know someone that has visible lines, let us know what they think.