3. Why Are There Dark Spots On My Skin and Clothing?
If you start to see dark spots on the skin in the genital area, get a magnifying glass and check for signs of crabs because you may have nymph or adult lice living there.
A dark or bluish spot will last for several days in the infested area. The dark spots on your under-clothing are attributed to lice feces. Occasionally you can see spots of blood over the bite area and in your underwear.
Bluish spots are the results of the parasites’ hypodermic proboscis cutting into a blood vessel. Also, lice parasites become darker in color after they feast.