Linear Hyperpigmentation along Blaschko's lines

What it means

Linear streaks and swirls of macular hyperpigmentation along the lines of Blaschko.

Blaschko's lines are attributed to the migration lines of epidermal cells during embryogenesis and are characterized by a V-shaped pattern on the posterior midline, S-shape on the abdomen, and spiral on the posterior scalp.

Rare diseases that can present with this1

The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions. A sign on this page is a conversation to have with a clinician, not a conclusion.

Part of the broader category