References UK clinical guidance from the NHS, the British HIV Association (BHIVA), and the British Association for Sexual Health and HIV (BASHH). Last updated: April 2026.
Kaposi’s sarcoma (KS) is a cancer that causes abnormal tissue to grow under the skin, in the lining of the mouth, nose or throat, or in other organs. It is caused by human herpesvirus 8 (HHV-8) and is strongly associated with HIV, particularly in people with low CD4 counts. KS was one of the first conditions recognised during the AIDS epidemic and remains an AIDS-defining illness.
With effective HIV treatment, KS has become much less common in the UK.
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What Causes KS?
KS is caused by HHV-8 (also called Kaposi sarcoma-associated herpesvirus or KSHV). Most people with HHV-8 never develop KS, but the virus can cause cancer when the immune system is weakened by HIV. KS almost always occurs when CD4 counts are low.
Symptoms
- Dark red, purple or brown patches or nodules on the skin
- Lesions can appear anywhere but are common on legs, face and genitals
- Lesions in the mouth (palate, gums)
- Swelling in the legs (lymphoedema)
- If internal: cough, breathlessness, abdominal pain, bleeding
| Location | Symptoms |
|---|---|
| Skin | Painless dark lesions, may be flat or raised |
| Mouth | Purple patches on palate or gums |
| Lungs | Breathlessness, cough |
| Gut | Bleeding, pain, diarrhoea |
| Lymph nodes | Swelling, especially legs |
Diagnosis
KS is diagnosed by biopsy of a skin lesion. If internal KS is suspected, imaging (CT scan) and endoscopy may be needed. HHV-8 testing can confirm the underlying viral cause.
Treatment
Starting or optimising ART
The most important treatment for HIV-related KS is effective antiretroviral therapy. Restoring the immune system often causes KS lesions to shrink or disappear entirely. Many cases of mild KS resolve with ART alone.
Chemotherapy
For more extensive or aggressive KS, chemotherapy is used alongside ART. Liposomal doxorubicin is the most common first-line option. Paclitaxel is used for relapsed disease.
Local treatments
For small, cosmetically bothersome skin lesions: radiotherapy, cryotherapy or surgical excision.
Prevention
- Start ART promptly after HIV diagnosis
- Maintain an undetectable viral load
- Report any new skin lesions or mouth changes to your HIV team
Read more: Cancer and HIV | Lymphoma and HIV | What is HIV?
Frequently Asked Questions
Can KS come back after treatment?
Yes, particularly if HIV is not well controlled. Staying on effective ART with an undetectable viral load is the best protection against recurrence.
Is KS contagious?
KS itself is not contagious, but HHV-8 can be transmitted through saliva. Most people who acquire HHV-8 never develop KS.
Does KS only affect people with HIV?
No. Other forms of KS exist in people without HIV, but HIV-related KS is the most common and aggressive form.
Related reading
- Blood Test for Syphilis, Hepatitis B and Hepatitis C
- Can You Get an STI From Being Fingered?
- Can You Catch an STI From a Toilet Seat?
- Can You Clear HPV Once You Have It?
- Can You Die From Hepatitis B?
Sources
- NHS — Sexual health conditions
- BASHH — UK clinical guidelines for STI management
- British HIV Association (BHIVA) — HIV treatment guidelines
- Terrence Higgins Trust — sexual health information
- UK Health Security Agency — STI surveillance data
Steve Page is a recognised expert on Sexually Transmitted Diseases (STDs) and STD treatments, having published numerous articles in peer-reviewed journals and presented his research at conferences around the world. He has an in-depth understanding of the latest medical research on STDs, and is an advocate for the development of new treatments and protocols to improve the health of those affected. In addition to his research, he has dedicated his career to understanding the causes and symptoms of STDs, as well as how to best treat those impacted.
