Kaposi's sarcoma is a rare type of cancer that can affect the skin and internal organs. It is caused by a virus, and is mainly seen in people with a poorly controlled or severe HIV infection.
It can also affect some people who have a weakened immune system for another reason, as well as people who have a genetic vulnerability to the virus.
Kaposi's sarcoma is caused by a virus called HHV-8 (human herpesvirus). ) This virus is thought to be spread during sex, through saliva, or from a mother to her baby during birth. HHV-8 is a relatively common virus and the vast majority of people who have it will not develop Kaposi's sarcoma. It only seems to cause cancer in some people with a weakened immune system and in some people who have a genetic vulnerability to the virus.
The most common initial symptom is the appearance of small, painless, flat and discoloured patches on the skin or inside the mouth. They're usually red or purple and look similar to bruises. Over time, the patches may grow into lumps known as nodules and may merge into each other. The internal organs can also be affected, including the lymph nodes, lungs and the digestive system, which can cause symptoms such as:
- Uncomfortable swelling in the arms or legs (lymphoedema)
- Breathlessness, coughing up blood and chest pain
- Nausea, vomiting, stomach pain and diarrhoea
The rate at which symptoms progress depends on the type of Kaposi's sarcoma. Most types get worse rapidly (weeks or months) without treatment, but some progress very slowly over many years.
With proper treatment, Kaposi's sarcoma can usually be controlled for many years. Deaths from the condition are uncommon in the UK. However, a complete cure for any type of Kaposi's sarcoma isn't always possible, and there's a chance the condition could recur in the future. If you think this is happening, contact your HIV clinic, hospital specialist or GP as soon as possible.