What is the significance of purplish spots with pneumocystis carinii pneumonia?

Not due to PCP: Although rarely, extrapulmonary involvement with pneumocystis occurs. Nonetheless, cutaneous purple colored lesions are probably kaposi's sarcoma, a malignancy caused by herpesvirus 8, and seen in profoundly immuno-suppressed individuals, usually aids. Both of these illness are exceptionally rare or non-existent in persons with a normal immune system & respond to correction of the CD4 counts.

Hard to say: Pneumocystis per se is not associated with purplish "spots", but since it is seen in the context of other diseases that damage the immune system it can be seen with other medical problems with purple spots. For ex one of the predisposing for pneumocystis is steroid medicine. Steroids can also cause easy bruising. In the setting of HIV a disease called kaposi's sarcoma this has purple spots, etc.