What is "millipede burn"

n. A brownish pigmentation or burn on the skin caused by the toxic liquid secreted by some millipedes.

Millipede burns are a cutaneous condition caused by some millipedes that secrete a toxic liquid that causes a brownish pigmentation or burn when it comes into contact with the skin. Some millipedes produce quinones in their defensive secretions, which have been reported to cause brown staining of the skin.