Thank you for visiting the EmpowHER community and sharing your question.
Pulmonary hypertension is the narrowing of the pulmonary arteries in the lung and can sometimes lead to bluish lips and skin. I did not find much research about the darkening of the skin other than a connection between PPH and Scleroderma. Scleroderma is a rare disease that involves the buildup of scar-like tissue in the skin. It also damages the cells that line the walls of the small arteries. Symptoms may cause the entire surface of the skin to get darker over time, and contain patches of abnormally pale skin.
Here is some information from the EmpowHER community about Scleroderma
Anon, I'm not sure exactly what could be causing the darkening of your skin and I suggest that you discuss this with your physician as soon as possible.
Will you call your doctor?