What Is VEXAS Syndrome? A Plain-Language Guide to the Autoinflammatory Condition That Attacks the Whole Body

Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026

Quick Answer

VEXAS syndrome is a rare autoinflammatory condition, caused by a UBA1 gene mutation that occurs after birth, in which the immune system causes inflammation throughout the body. [1] It mostly affects males older than 50, causing recurring fevers, skin rashes, joint pain and blood clots. [1] Without treatment it can be fatal. [1] Treatment includes corticosteroids, immune-suppressing medicines and sometimes bone marrow transplant. [2] [3]

What the research says

• VEXAS most often shows up on the skin and in the whole body, and the lungs, joints and eyes are frequently involved. A systematic review of 720 genetically confirmed patients (33 case reports and 21 case series from 32 countries) found skin involvement in 81.8% (95% CI 78.8% to 84.5%), constitutional (whole-body) symptoms in 69.4%, and respiratory disease in 61.3%. Joint involvement (47.3%), eye disease (44.3%) and venous blood clots (41.8%) were also common, and myelodysplastic syndrome occurred in 35.8% of patients. (Al-Hakim et al., Rheumatology, 2025) [5]

• Infections are frequent and can be severe. A systematic review of 57 studies (813 patients) found infections were severe in 40% to 60% of cases and fatal in 6% to 15%. Lung infections were the most common, followed by skin infections and bloodstream infection, and opportunistic infections were reported even in patients not receiving immunosuppressive therapy. (Ribier et al., Lancet Rheumatol, 2025) [6]

• Treatment responses differ by medicine, and the evidence is still limited. In a meta-analysis of 16 studies (367 patients), azacitidine produced a complete response in 67% of patients (95% CI 56% to 77%), JAK inhibitors in 42% (33% to 52%) and IL-6 inhibitors in 24% (15% to 32%). Adverse events were frequently observed, and the authors called for prospective clinical trials to confirm the results. (Kilic et al., Ann Hematol, 2025) [7]

What Is VEXAS Syndrome?

VEXAS syndrome is a condition in which the immune system attacks the body by mistake. [1] This is called an autoinflammatory condition. [1] VEXAS syndrome causes swelling and irritation, called inflammation, throughout the body. [1]

VEXAS syndrome is not common. [1] A gene change causes the condition, but the gene change happens after birth, so parents don't pass the change to children. [1] [3] Diagnosis involves genetic testing to look for the changed gene. [1]

Treatment most often involves medicines. [1] Sometimes it involves chemotherapy or a bone marrow transplant. [1] Without treatment, the condition can lead to death. [1]

What Does the Name "VEXAS" Mean?

The name VEXAS stands for the syndrome's features: vacuoles, E1 enzyme, X-linked, autoinflammation and somatic. [1] Each letter tells part of the story:

Letter	Stands for	What it means
V	Vacuoles	Empty spaces that form in atypical cells. [1] In VEXAS syndrome, vacuoles form in certain bone marrow cells. [1]
E	E1 enzyme	The enzyme affected in cells in people who have the changed gene. [1] The enzyme doesn't work right. [1]
X	X-linked	Refers to the X chromosome, where the changed gene is found. [1]
A	Autoinflammation	What happens when the immune system attacks the body. [1]
S	Somatic	The changed gene happens after birth and doesn't pass through families. [1]

Caused by a gene change that happens after birth — it is not inherited and cannot be passed from parent to child.

What Does VEXAS Syndrome Feel Like?

VEXAS syndrome symptoms can affect organs throughout the body and may differ from person to person. [1] Symptoms may differ from person to person and may include:

Warning sign	What it looks like
Fever that keeps coming back	Fevers that return again and again [1] [3]
Tiredness	Feeling exhausted [1] [3]
Painful skin rashes	Rashes on the skin that hurt [1]
Eye redness and irritation	Red, irritated eyes [1]
Joint pain and swelling	Joints that ache and swell [1]
Orchitis	Swelling and irritation of one or both testicles [1]
Chondritis	Swelling and irritation of the cartilage in the nose and ears [1] [3]
Breathing problems	Coughing and shortness of breath [1]
Blood clots	Clots that form and can travel [1]

What Causes VEXAS Syndrome?

The cause of VEXAS syndrome is a changed gene that happens after you're born. [1] [3] The changed gene is called a UBA1 mutation. [1] [3] Experts don't know the cause of this change. [1] The gene doesn't pass through families, called hereditary. [1] So people with the changed gene don't get it from their parents or pass it to their children. [1] [3]

Who Is at Higher Risk?

VEXAS syndrome affects more people assigned male at birth, because the changed gene that causes it is on the X chromosome. [1]

Risk factor	Why it matters
Sex assigned at birth	The changed gene that causes VEXAS syndrome happens on the X chromosome. [1] People assigned male at birth have only one X chromosome, so a change in this gene affects more people assigned male at birth than people assigned female at birth, who have two X chromosomes. [1]
Older age	Most people diagnosed with VEXAS syndrome are older than 50. [1] [3]

What Complications Can VEXAS Syndrome Cause?

VEXAS syndrome can cause complications such as infections, which mainly affect the lungs, skin and urinary tract and can be made more likely by treatment. [1]

Complication	What happens
Infections	Common complications of VEXAS syndrome; caused by bacteria, viruses or parasites; mainly affect the lungs, skin and urinary tract. [1] Medicines that lessen the immune system response to treat VEXAS can raise the risk of infections, and serious infections may raise the risk of death. [1]
Blood clots	Can happen in the arms, legs or lungs. [1] Once clots form, they can travel to other parts of the body and cause harm. [1]
Myelodysplastic syndromes	Conditions that keep blood cells from forming as they should, caused by issues with the spongy matter inside the bones where blood cells form (bone marrow); can lower blood cell counts. [1]
Bone marrow failure	Happens when bone marrow doesn't make enough red blood cells (carry oxygen), white blood cells (fight infection) or platelets (help blood to clot); may be life-threatening. [1]

Symptoms can look like many other inflammatory conditions — genetic testing is the only way to confirm the diagnosis.

How Is VEXAS Syndrome Diagnosed?

VEXAS syndrome may be hard to diagnose because of the range of possible symptoms and because the symptoms can be like those of other conditions that cause swelling and irritation, called inflammation. [2] The only way to confirm a diagnosis of VEXAS syndrome is through genetic testing. [2]

How Does the Genetic Test Work?

To do genetic testing, a healthcare professional takes a sample of blood or bone marrow and sends it to a lab to look for the changed gene that causes the condition. [2]

How Is VEXAS Syndrome Treated?

Treatment for VEXAS syndrome depends on the symptoms. [2] Treatment most often involves medicines for swelling and irritation, called inflammation, and medicines that lessen the immune system response. [2]

What Medicines Are Used?

Medicine type	How it works	What to know
Corticosteroids	Medicines such as prednisone ease inflammation and pain [2]	There can be serious side effects, and the risk rises when taken at high doses over a long time — bone thinning, easy bruising from skin thinning, weight gain, high blood sugar, cataracts and glaucoma, among others [2]
Immune-suppressing medicines	Medicines such as tocilizumab (Actemra, Tyenne, others) and Janus kinase inhibitors (JAKi) such as ruxolitinib (Jakafi), tofacitinib (Xeljanz) and baricitinib (Olumiant) help keep the immune system from attacking healthy cells [2]	These help with swelling and irritation while lowering the need for steroid medicines [2]
Chemotherapy medicines	Strong medicines that kill cells [2]	For some people, treatment may involve chemotherapy [2]

What About a Bone Marrow Transplant?

Also called a stem cell transplant, this procedure replaces bone marrow that isn't working well with new stem cells to make healthy bone marrow. [2] For VEXAS syndrome, the cells come from a donor. [2] This is called an allogenic transplant. [2]

Bone marrow transplant is a complex procedure. [2] It involves lowering the immune system response with chemotherapy and radiation so that the body can accept the donor cells. [2] [4] Possible complications include infections and failure of the donated stem cells. [2] [4]

For some people who get stem cells from a donor, the donor cells attack the tissues of the people who get them. [2] [4] This is called graft-versus-host disease. [2] [4] Complications of bone marrow transplant can be life-threatening. [2] [4]

A bone marrow transplant isn't for everyone. [2] Age and certain medical conditions may keep you from having one. [2] [4]

Without treatment, VEXAS syndrome can lead to death — researchers are still looking for the best ways to treat this newly identified condition.

Are There Potential Future Treatments?

VEXAS syndrome is a newly identified condition. [2] Researchers keep looking for the best ways to treat it. [2]

How Should You Prepare for Your Appointment?

You may start by seeing your main healthcare professional, who may send you to a specialist in arthritis and other inflammatory conditions, called a rheumatologist, or a specialist in blood conditions, called a hematologist. [2]

When you make the appointment, ask if there's anything you need to do before you go, such as fasting before certain tests. Make a list of your symptoms (including any that don't seem linked to the reason for your appointment) and when they began; key personal information, including major stresses, recent life changes and family medical history; all medicines, vitamins and other supplements you take, including dosages; and questions to ask your healthcare professional. Take a family member or friend along, if possible, to help you take in the information you get.

For VEXAS syndrome, some basic questions to ask include: What's likely causing my symptoms? What tests do I need? Is my condition likely to last or go away? What's the best course of action? I have other health conditions — how can I best manage them together? Are there restrictions I need to follow? Should I see a specialist? Are there brochures or fact sheets I can have, and what websites do you suggest?

Your healthcare professional may ask you questions such as: Have your symptoms stayed with you, or do they come and go? How bad are your symptoms? What, if anything, seems to make your symptoms better? What, if anything, seems to make your symptoms worse?

What is the bottom line on VEXAS syndrome?

VEXAS syndrome is a rare, newly identified condition in which a gene change that happens after birth — a UBA1 mutation — turns the immune system against the body, causing inflammation that can touch the skin, eyes, joints, cartilage, lungs, and blood. [1] [2] It strikes mostly men over 50, hides behind symptoms that look like many other inflammatory conditions, and can only be confirmed by genetic testing. [1] [2] That makes awareness of the symptom pattern — recurring fevers, painful rashes, swollen joints, inflamed ear and nose cartilage, breathing trouble, and blood clots — critically important, because without treatment the condition can lead to death. [1] Treatment today rests on corticosteroids, immune-suppressing medicines, and sometimes chemotherapy or a bone marrow transplant, each with real trade-offs, and researchers are still searching for the best ways to treat it. [2]

Take the Next Step

If you're a man over 50 with fevers that keep coming back, painful rashes, swollen joints, or inflamed ears and nose cartilage, see your healthcare professional — and ask about the possibility of VEXAS syndrome. Early diagnosis through genetic testing opens the door to treatment before serious complications such as infections, blood clots, or bone marrow failure take hold.

Frequently Asked Questions

What is VEXAS syndrome?

VEXAS syndrome is a condition in which the immune system attacks the body by mistake — an autoinflammatory condition that causes swelling and irritation, called inflammation, throughout the body. [1] It is not common. [1]

What does the name VEXAS stand for?

The name VEXAS stands for the condition's features: vacuoles (empty spaces that form in certain bone marrow cells), E1 enzyme (the enzyme affected by the gene change that doesn't work right), X-linked (the changed gene is on the X chromosome), autoinflammation (the immune system attacks the body), and somatic (the gene change happens after birth and doesn't pass through families). [1]

What causes VEXAS syndrome?

A changed gene that happens after you're born, called a UBA1 mutation. [1] [3] Experts don't know what causes this change, and it is not hereditary — people with the changed gene don't get it from their parents or pass it to their children. [1]

Who gets VEXAS syndrome?

Mostly people assigned male at birth who are older than 50. [1] [3] The changed gene sits on the X chromosome, and since males have only one X chromosome, the change affects them more often than people assigned female at birth, who have two X chromosomes. [1]

Is VEXAS syndrome contagious?

No. It is caused by a genetic change that happens after birth in certain cells. [1] [3] It cannot be passed through families [1] [3], and it is not caught from anyone.

What are the symptoms?

Fevers that keep coming back, tiredness, painful skin rashes, eye redness and irritation, joint pain and swelling, swelling and irritation of one or both testicles (orchitis), swelling and irritation of the cartilage in the nose and ears (chondritis), coughing and shortness of breath, and blood clots. [1] Symptoms differ from person to person and can affect organs throughout the body. [1]

How is it diagnosed?

The only way to confirm a diagnosis of VEXAS syndrome is through genetic testing. [2] A healthcare professional takes a sample of blood or bone marrow and sends it to a lab to look for the changed gene. [2] It can be hard to diagnose because the symptoms overlap with many other inflammatory conditions. [2]

What complications can it cause?

Infections (common, mainly affecting the lungs, skin, and urinary tract), blood clots in the arms, legs, or lungs, myelodysplastic syndromes (problems with the bone marrow that lower blood cell counts), and bone marrow failure, which may be life-threatening. [1]

How is VEXAS syndrome treated?

Treatment depends on the symptoms and most often involves medicines for inflammation and medicines that lessen the immune system response. [2] Sometimes treatment involves chemotherapy or a bone marrow transplant. [1] [2] Without treatment, the condition can lead to death. [1]

What are corticosteroids, and what are their side effects?

Corticosteroid medicines such as prednisone ease inflammation and pain. [2] There can be serious side effects, and the risk rises when they're taken at high doses over a long time — including bone thinning, easy bruising from skin thinning, weight gain, high blood sugar, cataracts and glaucoma, among others. [2]

What are immune-suppressing medicines?

Medicines that help keep the immune system from attacking healthy cells, which helps with swelling and irritation while lowering the need for steroid medicines. [2] They include medicines such as tocilizumab (Actemra, Tyenne, others) and Janus kinase inhibitors (JAKi) such as ruxolitinib (Jakafi), tofacitinib (Xeljanz) and baricitinib (Olumiant). [2]

When is a bone marrow transplant used?

For some people. [3] A bone marrow (stem cell) transplant replaces poorly working bone marrow with new stem cells from a donor — called an allogenic transplant — to make healthy bone marrow. It's a complex procedure with serious possible complications, including infections, failure of the donated stem cells, and graft-versus-host disease (when donor cells attack the recipient's tissues). [2] Age and certain medical conditions may keep you from having one. [2] [4]

What is graft-versus-host disease?

For some people who receive stem cells from a donor, the donor cells attack the tissues of the person who receives them. [2] [4] Complications of bone marrow transplant, including this, can be life-threatening. [2] [4]

Are there future treatments being researched?

Yes. VEXAS syndrome is a newly identified condition, and researchers keep looking for the best ways to treat it. [2]

What kind of doctor treats VEXAS syndrome?

You may start with your main healthcare professional, who may refer you to a rheumatologist (a specialist in arthritis and other inflammatory conditions) or a hematologist (a specialist in blood conditions). [2]

References

1. Mayo Clinic Staff. VEXAS syndrome: Symptoms and causes. Mayo Clinic. Last updated October 14, 2025. Accessed October 15, 2026. https://www.mayoclinic.org/diseases-conditions/vexas-syndrome/symptoms-causes/syc-20590472

2. Mayo Clinic Staff. VEXAS syndrome: Diagnosis and treatment. Mayo Clinic. Last updated October 14, 2025. Accessed October 15, 2026. https://www.mayoclinic.org/diseases-conditions/vexas-syndrome/diagnosis-treatment/drc-20590485

3. National Institute of Arthritis and Musculoskeletal and Skin Diseases. VEXAS syndrome. NIAMS. Accessed October 15, 2026. https://www.niams.nih.gov/labs/grayson-lab/vexas

4. Hertl M. Hematopoietic stem cell transplantation. Merck Manual Professional Version. Reviewed/revised August 2022; modified September 2022. Accessed October 15, 2026. https://www.merckmanuals.com/professional/immunology-allergic-disorders/transplantation/hematopoietic-stem-cell-transplantation

5. Al-Hakim A, Goldberg S, Gaillard S, et al. Clinical features in VEXAS syndrome: a systematic review. Rheumatology (Oxford). 2025;64(10):5217-5229. PMID 40570089. https://doi.org/10.1093/rheumatology/keaf293

6. Ribier V, Hadjadj J, Jachiet V, et al. Mapping the infectious burden in VEXAS syndrome: a systematic review and rationale for prevention. Lancet Rheumatol. 2025;7(10):e734-e744. PMID 40915301. https://doi.org/10.1016/S2665-9913(25)00225-5

7. Kilic B, Sacin E, Tanin MK, et al. Emerging treatment approaches for VEXAS syndrome: a systematic review and meta-analysis. Ann Hematol. 2025;104(5):2617-2630. PMID 40287866. https://doi.org/10.1007/s00277-025-06382-2

Medical disclaimer

This article is for general educational purposes only and does not replace professional medical advice, diagnosis, or treatment. Without treatment, VEXAS syndrome can lead to death, so see your healthcare professional for any symptoms that trouble you — especially recurring fevers, painful rashes, joint swelling, or breathing problems. Always consult a qualified healthcare provider for decisions about your care.