HIV causes changes to the immune system, which may result in skin irritation. An HIV rash that's itchy, reddish or dark purplish, and painful may develop.

Symptoms included headache, fever, stiff neck, nausea, vomiting and -- if the disease gets into the bloodstream -- a dark purple rash, according to the CDC. The disease spreads when bodily fluids ...

Freezing temperatures in New York caused a woman to develop an extensive purple, marbled rash all over her body. The 70-year-old was suffering from a rare disease, symptoms of which were triggered ...