Kaposi's sarcoma in Japan: Symptoms, Causes & Treatment | aihealz
ICD variantKaposi's sarcoma is a specific ICD-10 coded subtype of Kaposi's Sarcoma. The clinical content below covers Kaposi's Sarcoma in general.
OncologycriticalICD-10 · C46.9
Kaposi's sarcoma.Care & specialists in Japan
In Japan, kaposi's sarcoma is managed by oncologists. Kaposi's sarcoma (KS) is a vascular tumor caused by human herpesvirus 8 (HHV-8, also known as Kaposi sarcoma-associated herpesvirus, KSHV), most often appearing as red-purple or brown skin patches and nodules but able to involve lymph nodes, gut, and lungs. It occurs in four epidemiologic forms — classic (older Mediterranean and Eastern European men), endemic (sub-Saharan Africa), iatrogenic (organ-transplant recipients), and AIDS-related (HIV-positive patients).
Multiple Kaposi's sarcoma cutaneous lesions on the lower leg — classic presentation of AIDS-related KS. · Credit: CDC Public Health Image Library · Public Domain (CDC PHIL)
Kaposi's sarcoma (ICD-10: C46) is a low-grade vascular malignancy of endothelial origin caused by infection with human herpesvirus 8 (HHV-8 / KSHV), a gamma-2 herpesvirus discovered in 1994. The tumor arises from lymphatic endothelial cells that have been latently infected with HHV-8 and shows characteristic spindle-cell proliferation with slit-like vascular channels, hemorrhage, and hemosiderin deposition on histology. It is classified into four clinical-epidemiologic types: classic KS (indolent, lower-extremity disease in elderly Mediterranean, Eastern European, and Middle Eastern men); endemic (African) KS, a more aggressive form predating the HIV epidemic that affects all ages including children with lymphadenopathic disease; iatrogenic KS in organ transplant recipients on calcineurin inhibitors; and AIDS-related (epidemic) KS in HIV-positive individuals, which has been the defining cancer of the HIV pandemic. AIDS-related KS is staged by the AIDS Clinical Trials Group TIS system: Tumor extent (T0 limited / T1 extensive), Immune status (I0 CD4 >200 / I1 CD4 <200), and Systemic illness (S0 no systemic features / S1 systemic features present).
key facts
Prevalence
~34,000 new AIDS-related KS cases globally per year (GLOBOCAN 2022)
Demographics
AIDS-related and classic KS predominantly affect men (5-15x more than women); endemic KS more sex-balanced
Avg. age
Classic KS: peaks at 60-80 years; AIDS-related KS: peaks at 30-50 years
Global cases
Highest incidence in sub-Saharan Africa, where endemic and AIDS-related forms together drive 80% of global burden
Specialist
Oncology
ICD-10
C46.9
§ 02
How you might notice it
Oral Kaposi's sarcoma — purple lesion on the hard palate, common in advanced AIDS-related KS. · Credit: CDC Public Health Image Library · Public Domain (CDC PHIL)
The key symptoms of Kaposi's sarcoma are: Painless red, purple, or brown skin patches or plaques on the lower limbs, trunk, face, or oral mucosa, typically flat early then becoming raised over weeks to months., Multiple lesions appearing in symmetric distribution along skin tension lines (Blaschko or Langer lines), often the earliest distinguishing sign from solitary vascular tumors., Oral lesions on the hard palate, gums, or tongue — present in up to 25% of AIDS-related KS at diagnosis and often the first sign of advanced disease., Painful lymphedema, especially of the legs and genitalia, from lymphatic obstruction in advanced cutaneous or nodal KS., Hemoptysis, persistent cough, or shortness of breath from pulmonary KS — a poor prognostic feature., Gastrointestinal bleeding, abdominal pain, or weight loss from gut involvement (most often duodenum, stomach, or rectum) — frequently asymptomatic and found at endoscopy., Generalized lymph node enlargement, more typical of African endemic and pediatric forms..
01Painless red, purple, or brown skin patches or plaques on the lower limbs, trunk, face, or oral mucosa, typically flat early then becoming raised over weeks to months.
02Multiple lesions appearing in symmetric distribution along skin tension lines (Blaschko or Langer lines), often the earliest distinguishing sign from solitary vascular tumors.
03Oral lesions on the hard palate, gums, or tongue — present in up to 25% of AIDS-related KS at diagnosis and often the first sign of advanced disease.
04Painful lymphedema, especially of the legs and genitalia, from lymphatic obstruction in advanced cutaneous or nodal KS.
05Hemoptysis, persistent cough, or shortness of breath from pulmonary KS — a poor prognostic feature.
06Gastrointestinal bleeding, abdominal pain, or weight loss from gut involvement (most often duodenum, stomach, or rectum) — frequently asymptomatic and found at endoscopy.
07Generalized lymph node enlargement, more typical of African endemic and pediatric forms.
08Mucocutaneous bleeding from oral or genital KS lesions, especially in advanced disease.
09Constitutional B symptoms (fever, weight loss, night sweats) in extensive systemic disease — overlapping with HIV symptoms and multicentric Castleman disease.
early warning signs
•A new painless purple or brown patch on the leg, foot, face, or hard palate of a person with HIV infection
•Multiple small skin lesions appearing along the same line of the body — a clue to HHV-8-driven angiogenesis
•CD4 count below 200/µL or detectable HIV viral load in a person already known to be HIV-positive
•New skin lesion in an organ transplant recipient on cyclosporine or tacrolimus
•Persistent lymphadenopathy in a child or young adult from sub-Saharan Africa or Mediterranean region
● emergency signs
•Sudden shortness of breath or hemoptysis in a patient with KS — pulmonary KS or KS-associated multicentric Castleman disease requires urgent oncology evaluation
•Massive gastrointestinal bleeding from gut KS lesions — needs urgent endoscopy and possible transfusion
•Severe limb lymphedema with ulceration and superinfection — risk of cellulitis and sepsis
•Sudden facial swelling and respiratory compromise from oropharyngeal KS — possible airway obstruction needing ENT involvement
•High fever, cytopenias, and hepatosplenomegaly in a patient with KS — possible KS-associated multicentric Castleman disease or HHV-8 inflammatory cytokine syndrome (KICS)
§ 03
How it’s diagnosed
diagnosis
Diagnosis combines clinical recognition with histopathology. Suspicious skin or mucosal lesions undergo punch biopsy showing the hallmark histologic features: spindle-cell proliferation, slit-like vascular channels lined by atypical endothelial cells, extravasated red blood cells, hemosiderin deposition, and a lymphoplasmacytic infiltrate. Immunohistochemistry for HHV-8 latency-associated nuclear antigen (LANA-1) is essentially 100% sensitive and specific and is now considered required to confirm diagnosis. Once diagnosis is established, staging determines treatment. AIDS-related KS uses the AIDS Clinical Trials Group TIS classification: Tumor extent (T0 limited skin or oral / T1 extensive cutaneous, visceral, or tumor-associated edema), Immune status (I0 CD4 ≥200 / I1 CD4 <200), and Systemic illness (S0 / S1 with B symptoms, opportunistic infections, or KS-related visceral disease). Routine workup includes complete physical examination with documentation of skin lesion count and distribution, HIV testing and HIV viral load, CD4 count, complete blood count, comprehensive metabolic panel, HHV-8 PCR (in selected cases), chest imaging (CT in suspected pulmonary KS), and esophagogastroduodenoscopy plus colonoscopy in symptomatic patients or those with extensive disease. Differential diagnosis includes bacillary angiomatosis (Bartonella infection, treatable with antibiotics), pyogenic granuloma, melanoma, hemosiderotic dermatofibroma, and other vascular tumors. The combination of multiple symmetric purple-brown lesions in an HIV-positive person plus HHV-8 LANA-1 positivity on biopsy resolves nearly all cases.
Key tests
01
Punch biopsy of suspicious skin or mucosal lesionReference standard for diagnosis. Histology shows spindle-cell proliferation, slit-like vascular channels, extravasated red blood cells, and hemosiderin. Immunohistochemistry for HHV-8 LANA-1 confirms the diagnosis.
02
HHV-8 LANA-1 immunohistochemistryConfirms HHV-8 infection in tumor cells with near-100% sensitivity and specificity. Essential for distinguishing KS from histologic mimics including bacillary angiomatosis, pyogenic granuloma, and other vascular tumors.
03
HIV testing and CD4 count plus HIV viral loadIdentifies AIDS-related KS and stratifies immune status. CD4 count below 200/µL defines TIS Class I1 and influences chemotherapy choice and prognosis.
04
Chest CT or PET-CT for stagingDetects pulmonary KS (peribronchovascular nodules, pleural effusions), mediastinal lymphadenopathy, and other visceral involvement. PET-CT increasingly used for treatment response assessment.
05
Esophagogastroduodenoscopy (EGD) and colonoscopyDetects gastrointestinal KS, which is often asymptomatic but affects up to 40% of patients with extensive cutaneous disease. Important for staging and identifying bleeding risk.
06
Bronchoscopy (in suspected pulmonary KS)Direct visualization of typical KS lesions in the airways. Pulmonary KS has a characteristic endobronchial appearance; bronchial biopsy is often deferred due to bleeding risk from the highly vascular lesions.
Outlook
Prognosis varies dramatically by subtype. Classic KS is indolent — 10-year survival exceeds 85% and most patients die with rather than from KS. Iatrogenic KS often regresses with conversion to sirolimus; mortality from KS is uncommon when conversion is feasible. AIDS-related KS in the modern ART era has 5-year overall survival of 75-85% in well-resourced settings, a dramatic improvement from the pre-ART era when median survival was under 18 months. Adverse prognostic features include CD4 count below 200/µL, pulmonary involvement, extensive lymphedema, and systemic B symptoms. Endemic African KS has the worst prognosis globally, primarily due to limited access to liposomal doxorubicin and pomalidomide; the lymphadenopathic pediatric form is particularly aggressive. Treatment response is durable in most: at 5 years post-treatment of HIV-associated KS, the relapse rate is 10-20% in patients with sustained viral suppression. The introduction of pomalidomide and the active investigation of immune checkpoint inhibitors are expected to further improve outcomes. Quality-of-life impacts include cosmetic concerns, lymphedema, oral lesions interfering with eating, and the chronic relapsing course in extensive disease.
§ 04
Treatment & cost
medical treatments
✓Antiretroviral therapy (ART) for HIV-positive KS — integrase inhibitor-based regimens (bictegravir/TAF/FTC or dolutegravir/TAF/FTC)
✓Liposomal doxorubicin (Doxil 20 mg/m² IV every 2-3 weeks)
✓Paclitaxel (100 mg/m² IV every 2 weeks)
✓Pomalidomide (5 mg orally daily on days 1-21 of 28-day cycle)
surgical options
Excision of isolated symptomatic skin lesionsLocal clearance of excised lesion in 90%+; new lesions develop elsewhere in 60-80% over 5 years.
§ 05
Causes & risk factors
known causes
Infection with human herpesvirus 8 (HHV-8 / KSHV)
The necessary infectious cause, discovered by Chang and Moore in 1994. HHV-8 establishes lifelong latent infection in B-cells and endothelial cells. Seroprevalence varies sharply by geography: under 5% in most US/European populations, 20-50% in Mediterranean and Eastern European countries, and over 50% in much of sub-Saharan Africa.
Immunosuppression — HIV infection
HIV-induced CD4 depletion permits HHV-8 reactivation and drives endothelial cell transformation. KS risk in HIV-positive patients is 30,000-fold higher than baseline in some pre-ART cohorts; modern ART reduces this risk by over 90% but does not eliminate it.
Immunosuppression — iatrogenic
Calcineurin inhibitors (cyclosporine, tacrolimus) confer KS risk 200-fold higher than the general population in transplant recipients. Mechanism involves both general T-cell suppression and a calcineurin-specific pro-angiogenic effect. Switching to sirolimus (mTOR inhibitor) often produces tumor regression.
Genetic susceptibility (HLA variants)
HLA-DRB1*04 and DRB1*11 variants confer higher KS risk after HHV-8 infection. Other susceptibility loci including IL-6 promoter variants and immunogenetic factors partly explain the high incidence in Mediterranean populations and persistent endemic foci in Africa.
Geographic and demographic risk concentration
Classic KS clusters in Mediterranean and Eastern European men of Jewish, Italian, or Greek descent. Endemic KS persists in equatorial Africa. Same-sex sexual contact among men confers higher HHV-8 transmission rates. These distributions reflect HHV-8 transmission patterns rather than independent risk factors.
risk factors
HIV infection with low CD4 countmodifiable
AIDS-related KS risk rises steeply below CD4 200/µL. Modern ART reduces incidence by over 90% in the era of universal viral suppression.
HHV-8 seropositivitynon-modifiable
All KS cases are HHV-8-positive. Seroprevalence is region-dependent: under 5% in much of the US/Europe, 20-50% in Mediterranean countries, and over 50% in sub-Saharan Africa.
Solid organ transplantation on calcineurin inhibitorsmodifiable
Risk approximately 200-fold higher than general population; KS develops in 0.5-5% of transplant recipients in endemic-HHV-8 regions. Switching to sirolimus often produces regression.
Male sex and same-sex male contactnon-modifiable
All forms of KS show male predominance (5-15x in classic and AIDS-related forms). HHV-8 transmission rates are highest among men who have sex with men, partly explaining the male skew of AIDS-related KS.
Mediterranean, Eastern European, or sub-Saharan African ancestrygenetic
Geographic clustering reflects HHV-8 seroprevalence and immunogenetic susceptibility. Highest classic KS incidence is documented in Italian, Greek, Sephardic Jewish, and Middle Eastern men over 60.
Advanced age (classic KS)non-modifiable
Classic KS incidence rises with age and peaks at 60-80 years, presumably reflecting age-related immune senescence in HHV-8-positive individuals.
§ 06
Living with it
01Sustained ART for all HIV-positive individuals, achieving and maintaining viral suppression — the single most effective intervention to prevent AIDS-related KS
02Pre-exposure prophylaxis (PrEP) and condom use to reduce HIV transmission in MSM and other high-risk groups
03Use of sirolimus rather than calcineurin inhibitors in transplant recipients from HHV-8 endemic regions where feasible
04HHV-8 transmission risk reduction — avoid shared saliva exposure with known HHV-8-positive partners (limited evidence)
05Annual skin and oral examination for all HIV-positive patients and HHV-8-seropositive transplant recipients
recommended foods
•Balanced diet with adequate protein and calories to maintain weight during chemotherapy
•Antioxidant-rich vegetables and fruits as part of a Mediterranean-style pattern
•Adequate iron and folate to prevent worsening anemia during chemotherapy
•Hydration adequate to support kidney function on nephrotoxic regimens
foods to avoid
•Excessive alcohol during chemotherapy due to additive hepatotoxicity
•Raw or undercooked foods during chemotherapy-induced neutropenia
•Grapefruit juice during sirolimus or calcineurin inhibitor therapy due to CYP3A4 interactions
•Crash diets or extreme weight-loss attempts during active treatment
§ 07
When to seek help
why see an oncology
All suspected KS should be evaluated by an oncologist with HIV/oncology experience or in dedicated HIV-oncology multidisciplinary clinics. Infectious disease involvement is essential for AIDS-related KS to optimize ART and manage opportunistic infections. Transplant nephrologists/hepatologists guide iatrogenic KS management with sirolimus conversion. Dermatology contributes to skin lesion assessment and local therapy planning. Palliative care has a role throughout extensive disease.
01Pulmonary KS — poor prognostic feature with median survival of 12-18 months without effective chemotherapy and ART
02Gastrointestinal KS with chronic bleeding, iron-deficiency anemia, or obstruction
03Severe lymphedema with skin breakdown, recurrent cellulitis, and reduced function
04KS-associated multicentric Castleman disease (HHV-8-driven lymphoproliferation) and KSHV inflammatory cytokine syndrome (KICS) — severe systemic illnesses with high mortality
05Cardiotoxicity from cumulative anthracycline exposure, particularly with conventional doxorubicin
06Opportunistic infections in patients with persistent low CD4 counts despite ART
choosing the right hospital
01Established HIV-oncology multidisciplinary clinic with infectious disease and oncology integration
02Access to liposomal doxorubicin, paclitaxel, and pomalidomide formularies
03Radiation oncology service for palliative radiation of localized lesions
04Pathology service capable of HHV-8 LANA-1 immunohistochemistry
05Linkage to clinical trials through AIDS Malignancy Consortium or equivalent networks
Essential facilities
AIDS Malignancy Consortium centers (US National Cancer Institute network)National Cancer Institute Division of Cancer Treatment HIV-Oncology ProgramChelsea and Westminster Hospital (UK) — long-established HIV oncology serviceUganda Cancer Institute — major sub-Saharan African KS research and treatment center
Classic Kaposi sarcomaIndolent form in elderly men of Mediterranean, Eastern European, or Middle Eastern descent. Slow-growing red-purple patches and plaques on lower legs and feet. Disease progression over decades; rarely fatal. Discovered and described by Moritz Kaposi in 1872.
Endemic (African) Kaposi sarcomaPre-HIV form endemic in equatorial Africa. Four subtypes: nodular (similar to classic), florid (locally aggressive), infiltrative (deep tissue and bone), and lymphadenopathic (mostly children, often without skin lesions, aggressive course).
Iatrogenic Kaposi sarcomaDevelops in transplant recipients on immunosuppression, particularly calcineurin inhibitors (cyclosporine, tacrolimus). Incidence ~200-fold higher in transplant patients than general population. Often regresses with switch to sirolimus or reduced immunosuppression.
AIDS-related (epidemic) Kaposi sarcomaMost common HIV-associated cancer globally. Strongly correlated with CD4 count and HIV viremia. ART has reduced US/European incidence by over 80%; remains high in sub-Saharan Africa where ART access is incomplete and HHV-8 seroprevalence exceeds 50%.
Living with Kaposi's sarcoma
Timeline
Cutaneous lesions begin to flatten and lose pigment within 4-8 weeks of effective ART or chemotherapy. Complete clinical response usually requires 4-6 months of treatment. Visceral disease responds over similar timeframes when imaging-monitored. Radiation-treated lesions regress over 4-12 weeks. Lymphedema improvement is slower and often partial, requiring sustained compression and rehabilitation. Pomalidomide responses develop over 2-4 cycles (8-16 weeks). Maintenance with continuous ART is required indefinitely; chemotherapy is held once best response is achieved and reintroduced on progression.
Lifestyle
01Adhere strictly to ART or transplant immunosuppression regimens as prescribed
02Use sun protection — UV light may stimulate KS lesions
03Manage lymphedema with compression garments, manual lymphatic drainage, and elevation
04Treat skin infections promptly to prevent superinfection of fragile KS lesions
05Maintain good oral hygiene; oral KS may bleed and is at risk of infection
06Stop smoking — independent risk factor for lung cancer and reduces tolerance of chemotherapy
Daily management
01Take ART or transplant medications at the same time every day without interruption
02Inspect skin, oral cavity, and feet weekly for new lesions or changes; report changes promptly
03Use prescribed compression garments daily if lymphedema is present
04Attend all chemotherapy and oncology appointments; missed doses reduce efficacy
05Keep an updated list of all medications and recent lab results when traveling
Exercise
Regular moderate exercise (walking, swimming, cycling) is encouraged throughout treatment. Compression garments and limb elevation help patients with lymphedema participate safely. Avoid contact sports during chemotherapy-induced thrombocytopenia or in patients with advanced cutaneous disease prone to bleeding. Strength training preserves muscle mass during treatment.
Choosing a doctor
Look for an oncology practice with experience in HIV-associated malignancies; in the US these are commonly within AIDS Malignancy Consortium member institutions or academic HIV-oncology programs. Confirm access to liposomal doxorubicin and second-line agents including pomalidomide. For transplant patients, the transplant team should co-manage with oncology. Continuity matters — KS is a chronic relapsing condition in many patients.
Kaposi's sarcoma is a vascular cancer caused by human herpesvirus 8 (HHV-8). It typically appears as red, purple, or brown skin lesions but can also involve the mouth, lymph nodes, gut, and lungs.
What causes Kaposi sarcoma?▾▴
Kaposi sarcoma is caused by infection with human herpesvirus 8 (HHV-8), also known as Kaposi sarcoma-associated herpesvirus (KSHV).
Is Kaposi sarcoma cancer?▾▴
Yes. Kaposi sarcoma is classified as a low-grade vascular malignancy. Unlike many cancers it does not typically metastasize through bloodstream spread; instead, multiple new lesions develop because of widespread HHV-8 infection of endothelial cells.
Is Kaposi sarcoma always related to HIV?▾▴
No. AIDS-related KS is the most common form globally, but classic KS (elderly Mediterranean men), endemic African KS (pre-HIV, all ages), and iatrogenic KS (organ transplant recipients) all occur without HIV infection. All forms share HHV-8 as the necessary infectious cause.
How is Kaposi sarcoma diagnosed?▾▴
Diagnosis requires biopsy of a suspicious skin or mucosal lesion. Histology shows characteristic spindle cells, slit-like vascular channels, and red-cell extravasation.
What does Kaposi sarcoma look like?▾▴
Kaposi sarcoma typically appears as red, purple, or brown patches, plaques, or nodules on the skin or mucous membranes. Lesions are often multiple and symmetric, can appear along skin tension lines, and are painless. Common sites include the lower legs, feet, face, hard palate, and gums.
How is Kaposi sarcoma treated?▾▴
Treatment depends on type and extent. For AIDS-related KS, antiretroviral therapy (ART) is the foundation — over 60% of limited-disease cases respond to ART alone. Extensive or visceral disease adds chemotherapy with liposomal doxorubicin or pomalidomide.
Can Kaposi sarcoma be cured?▾▴
Limited Kaposi sarcoma can go into long-term remission, but HHV-8 remains in the body lifelong and recurrence is possible. AIDS-related KS responds dramatically to ART with sustained complete response in 60-80% of limited disease. Iatrogenic KS often fully regresses with sirolimus.
How is HHV-8 transmitted?▾▴
HHV-8 transmits primarily through saliva and to a lesser extent through sexual contact and shared injection equipment. Mother-to-child transmission via saliva accounts for much endemic-area childhood infection. Casual contact does not transmit it.
What is the survival rate for Kaposi sarcoma?▾▴
Modern survival is excellent in well-resourced settings: 5-year overall survival exceeds 75-85% for AIDS-related KS on ART. Classic KS has 10-year survival above 85%. Pulmonary KS and disseminated disease are higher-risk.
Can children get Kaposi sarcoma?▾▴
Yes, particularly the endemic African form and AIDS-related KS in pediatric HIV. The lymphadenopathic pediatric form, common in equatorial Africa, presents with generalized lymphadenopathy without skin lesions and has a poor prognosis without prompt chemotherapy.
Why does Kaposi sarcoma cause swelling?▾▴
Kaposi sarcoma lesions and KS-affected lymph nodes obstruct lymphatic drainage, causing lymphedema in the affected limb, face, or genitalia. Lymphedema can be severe, painful, and prone to recurrent cellulitis.
Does Kaposi sarcoma spread to organs?▾▴
Yes. KS commonly involves lymph nodes, the gastrointestinal tract (often asymptomatic, found at endoscopy in up to 40% of extensive cutaneous cases), and the lungs (a poor prognostic site). Bone and central nervous system involvement are rare.
Can ART alone cure AIDS-related Kaposi sarcoma?▾▴
ART alone produces sustained complete or partial response in 60-80% of patients with limited skin-only (T0) AIDS-related KS. Extensive disease (T1) usually requires concurrent chemotherapy. ART should be started promptly — within 2 weeks of diagnosis — regardless of CD4 count.
What is pomalidomide for Kaposi sarcoma?▾▴
Pomalidomide is an oral immunomodulator with anti-angiogenic and anti-inflammatory effects, approved by the FDA in 2020 for KS after standard therapy. It works in both HIV-positive and HIV-negative patients with response rates of 60-70%.
Can I prevent Kaposi sarcoma?▾▴
The most effective prevention is preventing HIV infection (with PrEP, condoms, and harm reduction) and, for HIV-positive individuals, sustained ART with full viral suppression. Transplant recipients in HHV-8-endemic regions may benefit from sirolimus-based regimens when clinically feasible.
Does Kaposi sarcoma always appear on the skin?▾▴
No. While most cases include skin involvement, pure visceral KS — particularly pulmonary or gastrointestinal — does occur, and lymphadenopathic pediatric African KS often has no skin lesions. Endoscopy, bronchoscopy, or imaging may be needed in patients with consistent symptoms but no skin findings.
Will Kaposi sarcoma lesions disappear with treatment?▾▴
Many lesions flatten substantially and fade, but residual pigmentation (hemosiderin) often persists for months to years even after the active disease is gone. Radiation-treated lesions usually clear most completely.
Are men more likely to get Kaposi sarcoma than women?▾▴
Yes. All forms show male predominance. Classic KS affects men 10-15 times more than women; AIDS-related KS affects men 5-10 times more, partly because HHV-8 transmission is high among men who have sex with men. Endemic African KS has the most balanced sex ratio but still favors men 2-3 fold.
Is HHV-8 the same as the herpes virus that causes cold sores?▾▴
No. HHV-8 (Kaposi sarcoma-associated herpesvirus) is a gamma-2 herpesvirus, related to Epstein-Barr virus. Cold sores are caused by herpes simplex virus type 1 (HSV-1), an alpha-herpesvirus. Both establish lifelong latent infections but cause different diseases through different mechanisms.
