What causes skin to turn dark purple to black

Hello Anon

Thank you for writing.

Skin color can change with cellulitis (and after) - from a light pink all the way to a dark purple.

Symptoms may begin within hours or days and can include:

Skin inflammation that begins in a small area and spreads with:
Redness
Pain or tenderness
Swelling
Warmth
A red streak (possibly)
Swollen lymph nodes
Fever or chills
Fatigue
Headache
Cellulitis near the eyes may cause pain with eye movements and should be treated urgently

If your skin is turning black this may be another infection or a lack of oxygen and needs to be reported to a doctor asap.
Best,
Susan