If HHV-8 can cause KS in the presence of an HIV immune defect, what is that causes KS to develop in someone who is otherwise healthy, not of Jewish or Mediterranean extraction, and not HIV-positive?

I have a good friend, HIV-negative, who has developed a KS lesion on his ear. Also, my dermatologist told me recently that he is seeing more and more HIV-negative gay men with KS. Is this something you have observed? What could be causing it if HHV-8 is not sufficient by itself?

Also, my friend's doctor says he must have a CAT scan done. What is the purpose of this in relation to KS?

Kaposi's sarcoma is caused by HHV8 (also known as human herpesvirus-8 or Kaposi's sarcoma herpes virus). It is the virus which causes ALL forms of KS-- this includes AIDS-related KS, KS in otherwise healthy folks who are not HIV-positive, in transplant patients, in gay men who are HIV-negative, and so on. HHV8 infection is quite common around the world, particularly in certain geographic locations. Only a small percent of folks who are HHV8 infected actually develop KS. You are more likely to develop KS if you are HHV8 infected, and you are either HIV-infected or elderly (e.g. Mediterranean elderly men). However, I have in my practice, and other KS doctors have in their practices, folks with KS who are neither elderly nor HIV- positive.

As for your CT scan question, I typically do a carful physical exam in my patients, check their stool for blood (a sign of internal KS) and do a chest x-ray. CT scans are typically not necessary, but in your friend's case, maybe it is. It's hard for more to know without knowing more of the details.