Behçet's Disease

Introduction

Behçet’s disease — also called Behçet’s syndrome — is a long-term inflammatory condition that can affect many parts of the body. Most people first notice it through painful mouth ulcers that keep coming back, along with genital ulcers, skin changes, or eye inflammation. For some, the disease also involves the joints, blood vessels, brain, or digestive tract.

If you have been diagnosed with Behçet’s disease, or your doctor suspects it, you are probably trying to understand what to expect in the months and years ahead. The condition behaves differently from one person to the next. Some people have mild symptoms that flare from time to time. Others have more serious involvement of the eyes or blood vessels that needs strong, ongoing treatment. The good news is that with the right combination of medicines and follow-up, most people can keep flares under control and protect their long-term health.

This guide explains what Behçet’s disease is, what causes it, how it is diagnosed, the treatments doctors use today, and what life with the condition typically looks like. It is written for people who already have a diagnosis or are being investigated, and for parents of children with the condition.

What Is Behçet’s Disease?

The disease is named after Hulusi Behçet, a Turkish dermatologist who described it in 1937. It is most common in countries along the historic Silk Road, including Turkey, Iran, the Middle East, Central Asia, China, Korea, and Japan. It is less common in Western Europe, the Americas, and Africa, although it occurs everywhere. In India it is uncommon but recognised, and rheumatology centres see it regularly enough to manage it well.

Behçet’s disease usually begins between the ages of 20 and 40, although it can start in childhood or later in adulthood. Both men and women are affected, but the disease tends to be more severe in men and in those who develop it at a younger age. It is not contagious, not inherited in a simple way, and not caused by anything the patient did or did not do.

The condition is described as relapsing and remitting. This means symptoms come in flares, settle down for periods of weeks, months, or years, and then return. Over many years, flares often become less frequent and less severe in many people, although this is not guaranteed.

Causes and Risk Factors

The exact cause of Behçet’s disease is not known. Researchers believe it is what is called an autoinflammatory condition, in which the body’s immune system becomes overactive and attacks healthy tissues, particularly the lining of blood vessels. The trigger appears to involve a combination of genetic susceptibility and something in the environment, possibly an infection, that sets off the immune response in someone already at risk.

Genetic factors

The strongest known genetic link is a gene called HLA-B51. This gene is part of the immune system and is found more often in people with Behçet’s disease than in the general population, especially in populations along the Silk Road. However, carrying HLA-B51 does not mean someone will develop Behçet’s — many healthy people carry the gene and never get the disease. Testing for HLA-B51 is sometimes used to support a diagnosis but is not by itself diagnostic.

Behçet’s disease occasionally runs in families, but most cases happen in people with no relative who has the condition.

Environmental triggers

Researchers suspect that bacterial or viral infections may trigger the immune system to misfire in genetically susceptible people. Certain mouth bacteria have been studied as possible triggers, which would help explain why mouth ulcers are so often the first sign.

Risk factors

• Geographic origin: people whose ancestry traces to countries along the Silk Road have a higher risk
• Age: most cases begin between 20 and 40, but onset at any age is possible
• Sex: men and women are both affected; men, and those who develop the disease younger, tend to have more severe disease
• Family history: a small increase in risk if a close relative has Behçet’s

Signs and Symptoms

Behçet’s disease can affect almost any organ. Few people have all of the symptoms, and the pattern usually develops over time. For someone already diagnosed, this section is a guide to recognising flares and watching for new organ involvement.

Mouth ulcers

Painful mouth ulcers (aphthous ulcers) are the most common feature and are usually the first symptom. They look like round or oval sores with a yellow or white centre and a red border, and they appear on the tongue, gums, inner cheeks, or lips. They can come singly or in clusters, heal in one to three weeks, and tend to come back. Almost everyone with Behçet’s has them.

Genital ulcers

Genital ulcers look similar to mouth ulcers but appear on the scrotum, vulva, or vagina. They are usually painful and often leave scars when they heal. They are less frequent than mouth ulcers but are more specific to Behçet’s disease, which is why doctors ask about them.

Skin problems

• Acne-like spots on the face, back, and chest, often in adults past the usual age for acne
• Tender red nodules on the shins, called erythema nodosum
• Pathergy: an exaggerated skin reaction to a needle prick or small injury, where a small red bump or pustule forms within 24 to 48 hours. This is tested by some doctors as part of diagnosis

Eye involvement

Eye problems are one of the most serious aspects of Behçet’s disease. The most common is uveitis, inflammation inside the eye. It can cause:

• Red, painful eyes
• Sensitivity to light
• Blurred vision or floaters
• Loss of vision if not treated

Behçet’s often affects the back of the eye (posterior uveitis) and the retina, which can permanently damage sight if flares are not treated promptly. Any new eye symptoms in someone with Behçet’s disease should be assessed urgently.

Joint problems

About half of people with Behçet’s have joint pain or swelling at some point, most often in the knees, ankles, wrists, or elbows. The arthritis is usually not damaging to the joints over the long term, although it can be uncomfortable during flares.

Blood vessel involvement

Behçet’s can inflame veins and arteries. Common patterns include:

• Deep vein thrombosis (DVT): a blood clot in a leg vein, causing a swollen, painful calf or thigh
• Superficial vein inflammation showing as tender red cords under the skin
• Aneurysms (ballooning of an artery wall), most worrying when they affect the lung arteries

Nervous system involvement

Around one in ten people develop neurological problems, sometimes called neuro-Behçet’s. Symptoms may include persistent headache, weakness on one side, balance or vision changes, confusion, or seizures. This is a serious form of the disease and needs prompt specialist care.

Digestive tract

Ulcers can also form in the gut, most often in the lower small intestine and the start of the colon. Symptoms include abdominal pain, diarrhoea, and sometimes blood in the stool. Gut involvement is more common in patients of East Asian background.

Diagnosis

There is no single blood test or scan that confirms Behçet’s disease. The diagnosis is clinical — doctors put together the pattern of symptoms over time, examine the patient, and rule out other conditions. This can take months or years from the first symptom, especially when mouth ulcers appear alone for a long time before other features develop.

Clinical criteria

Rheumatologists use criteria such as the International Criteria for Behçet’s Disease (ICBD) and the older International Study Group criteria. These award points for the typical features — mouth ulcers, genital ulcers, eye involvement, skin lesions, vascular involvement, and a positive pathergy test — and help doctors decide whether the picture fits.

Tests doctors may order

While there is no diagnostic test, several investigations help support the diagnosis and check which organs are involved:

• Blood tests for inflammation (ESR, CRP), to rule out infections and other autoimmune conditions, and sometimes HLA-B51 genetic testing
• Pathergy test: a small needle prick on the forearm, reviewed 24 to 48 hours later to see whether an unusual bump forms
• Eye examination by an ophthalmologist, ideally with experience in inflammatory eye disease, including detailed views of the retina
• Imaging such as ultrasound, CT, or MRI to look at blood vessels, the brain, or the gut when those areas are suspected
• Endoscopy if gut involvement is suspected, to look directly at ulcers

Differential diagnosis

Other conditions can produce overlapping symptoms and need to be considered. These include inflammatory bowel disease, lupus, reactive arthritis, herpes infections, other forms of vasculitis, and simple recurrent mouth ulcers without systemic disease. Sorting these out is part of what a rheumatologist does during the diagnostic process.

Treatment and Management

Behçet’s disease is treated based on which organs are affected and how severe the disease is. The European Alliance of Associations for Rheumatology (EULAR) publishes widely used recommendations, most recently updated in 2018, that guide treatment choices. The overall aim is to suppress inflammation quickly during flares, prevent damage to important organs (especially the eyes, blood vessels, brain, and gut), and reduce the frequency of flares over the long term.

A rheumatologist usually coordinates care, often working with an ophthalmologist for eye involvement, a neurologist for brain involvement, a vascular specialist for blood vessel problems, and a gastroenterologist for gut involvement.

Treating mouth and genital ulcers

For mild mucocutaneous (mouth and skin) disease, doctors often start with:

• Topical treatments: corticosteroid mouthwashes, gels, pastes, or pastilles applied directly to ulcers; similar treatments for genital ulcers
• Colchicine: an oral medicine that has been used for many years and is recommended by EULAR as a first-line treatment to reduce ulcer recurrence, particularly for skin and joint involvement

When ulcers are frequent or severe despite these measures, doctors may add stronger immune-modifying drugs.

Treating eye involvement

Eye disease is treated quickly and aggressively to protect sight. Treatment may include:

• Corticosteroids as eye drops, injections around the eye, or systemic tablets
• Immunosuppressants such as azathioprine, ciclosporin, or mycophenolate
• Biologic drugs: EULAR recommendations support the use of anti-TNF medicines such as infliximab and adalimumab for severe or sight-threatening eye disease. Interferon-alpha is another option in some centres

Treating joint problems

Joint pain is often managed with colchicine. If flares are more severe, short courses of oral corticosteroids or other immunosuppressants may be used. Non-steroidal anti-inflammatory drugs (NSAIDs) can help with pain.

Treating blood vessel involvement

• High-dose corticosteroids along with immunosuppressants such as cyclophosphamide or azathioprine for serious vein clots and aneurysms
• Anti-TNF biologics are used in some patients who do not respond to standard treatment
• Anticoagulation (blood thinners) for clots is used selectively and only after aneurysms in the lung arteries have been ruled out, since bleeding into such aneurysms can be dangerous

Treating neurological involvement

Brain involvement is treated as a medical emergency. High-dose corticosteroids are usually given first, followed by long-term immunosuppression with medicines such as azathioprine, mycophenolate, or anti-TNF biologics. Ciclosporin is generally avoided in neuro-Behçet’s because of concerns it may worsen the condition.

Treating gastrointestinal involvement

Gut ulcers are treated with corticosteroids and immunosuppressants such as azathioprine or mycophenolate. Biologic drugs, particularly anti-TNF agents, are increasingly used. Surgery may be needed for complications such as bleeding, perforation, or strictures, but doctors avoid operating during active inflammation when possible because healing is poor.

Medicines you may hear about

The drugs used for Behçet’s disease come from different families. Knowing the categories may help when talking with your doctor:

• Topical and oral corticosteroids (such as prednisolone) reduce inflammation quickly but have side effects when used long-term
• Colchicine is taken as a daily tablet and is often the foundation of treatment for skin, mucous membrane, and joint involvement
• Conventional immunosuppressants: azathioprine, mycophenolate, ciclosporin, methotrexate, cyclophosphamide
• Biologic drugs: anti-TNF medicines such as infliximab and adalimumab; interferon-alpha; and newer agents being studied in clinical trials
• Apremilast, an oral medicine approved in several countries for treatment-resistant mouth ulcers in Behçet’s disease

Each of these medicines has its own side effects and monitoring requirements. Doctors discuss the balance of benefits and risks with each patient before starting them.

Lifestyle and Self-Management

Medical treatment is the main way to control Behçet’s disease, but several practical steps can help you live with it more comfortably and reduce flares.

Managing mouth ulcers day to day

• Use a soft toothbrush and gentle, alcohol-free mouthwash
• Avoid foods that sting ulcers — spicy, salty, acidic, or very hot foods often make pain worse
• Try to identify any food triggers; some people find that nuts, tomatoes, citrus, or certain spices set off flares
• Stay well hydrated; dehydration can make oral symptoms worse

Skin and wound care

Because of the pathergy response, even small skin injuries can trigger a skin lesion or worsening inflammation. Doctors often advise:

• Telling any healthcare professional you have Behçet’s before injections, blood tests, or minor procedures
• Avoiding non-essential cosmetic procedures that puncture the skin
• Treating cuts and scrapes carefully to lower infection risk

Rest, stress, and sleep

Many people notice that flares come on after periods of physical or emotional stress, illness, or poor sleep. Pacing activity, building in rest, and taking stress seriously are all useful. Practical tools such as relaxation exercises, regular sleep routines, and counselling support can help.

Exercise

Gentle to moderate regular exercise — walking, swimming, cycling, yoga — helps mood, sleep, fatigue, and joint health. During flares, particularly with joint or eye involvement, easing back is sensible. A physiotherapist can help with a programme suited to your level of activity and any joint problems.

Diet

There is no specific diet that treats Behçet’s disease. A balanced diet that supports general health is sensible. People taking long-term corticosteroids are usually advised to keep calcium and vitamin D intake adequate, watch weight gain, and limit added sugar and salt. If gut involvement is part of your disease, a dietitian can help adjust your diet during flares.

Smoking and alcohol

Smoking damages blood vessels and is particularly unwise in a disease that already inflames them. Stopping smoking is one of the more impactful changes a person with Behçet’s can make. Alcohol can interact with several of the medicines used in treatment, so doctors usually advise moderation and discussion of individual limits.

Monitoring and Follow-Up

Even when Behçet’s disease is quiet, regular follow-up is important. New organ involvement can appear years after diagnosis, and many of the medicines used need monitoring.

Routine visits

How often you see your rheumatologist depends on how active the disease is and which organs are affected. People with stable, mild disease may be seen every six to twelve months. Those with active eye, neurological, vascular, or gut disease are seen more often.

Eye checks

Regular eye examinations are important even if you have never had eye symptoms. Anyone with Behçet’s disease should report new redness, pain, floaters, light sensitivity, or blurred vision urgently.

Blood tests

Routine blood tests are used to:

• Check markers of inflammation (ESR and CRP)
• Watch for side effects of immunosuppressant medicines on the liver, kidneys, and blood cells
• Screen for infection risks before starting biologic drugs (for example, hepatitis B, hepatitis C, HIV, and tuberculosis)

Vaccinations

People taking immunosuppressants need careful planning around vaccines. Inactivated vaccines (such as influenza, pneumococcal, hepatitis B, and COVID-19 vaccines) are generally encouraged and may be more important than for the general population. Live vaccines (such as MMR, yellow fever, and the older shingles vaccine) are usually avoided during strong immunosuppression. Your rheumatologist can advise on timing.

Complications

The complications of Behçet’s disease come from two sources: the disease itself and the side effects of long-term treatment.

From the disease

• Vision loss from repeated or untreated eye inflammation. Modern treatment has greatly reduced this risk, but it remains the most feared complication
• Blood clots and aneurysms, sometimes in dangerous locations such as the lung arteries or the major veins of the abdomen
• Stroke or other brain injury from neuro-Behçet’s
• Gut bleeding, perforation, or narrowing from intestinal ulcers
• Scarring from severe genital or skin ulcers
• Fatigue and depression, which are common in any long-term inflammatory illness

From treatment

Long-term corticosteroids can cause weight gain, raised blood pressure, raised blood sugar, bone thinning (osteoporosis), and cataracts. Immunosuppressants and biologics raise the risk of infections. Each medicine has its own profile, and doctors monitor for these effects through blood tests and clinical review. The aim of treatment planning over time is usually to bring the disease under control with corticosteroids and then taper them, relying on the longer-term immunosuppressants or biologics for maintenance.

Living with Behçet’s Disease

A diagnosis of a long-term inflammatory disease changes how you think about your health. It is normal to feel anxious about flares, frustrated by visible symptoms, or worried about the future. Most people find that the early years — while treatment is being adjusted and the pattern of the disease becomes clearer — are the hardest, and that life settles as control improves.

Work and study

Most people with Behçet’s disease can work and study, although flares may require time off and accommodations. Talking with employers or teachers in advance about possible flares, and the occasional need for medical appointments, can prevent problems later. A pacing approach — balancing demanding periods with recovery — helps protect energy.

Mental health

Living with a chronic condition takes a real emotional toll. Anxiety, low mood, and difficulty sleeping are common and deserve to be taken seriously. Counselling, peer support, and, where appropriate, medication can all help. Tell your rheumatologist if you are struggling; mental health is a routine part of long-term care.

Relationships and intimacy

Genital ulcers and the side effects of treatment can affect intimate relationships. Speaking openly with a partner, and with your doctor, helps. There are practical measures and treatments that can reduce discomfort during flares, and doctors are used to these conversations.

Pregnancy

Many people with Behçet’s disease have successful pregnancies. Disease activity sometimes improves during pregnancy and sometimes flares. Planning ahead is important because some of the medicines used — particularly methotrexate, mycophenolate, and cyclophosphamide — are not safe in pregnancy and need to be changed in advance. Others, such as colchicine, azathioprine, and certain biologics, are considered compatible. A pre-pregnancy discussion with your rheumatologist and an obstetrician with experience in autoimmune disease helps plan the safest path.

Support groups

Connecting with others who have Behçet’s disease can be valuable, especially because the condition is uncommon and many people have never met anyone else with it. National and international patient organisations run online groups, information days, and helplines.

Behçet’s Disease in Children

Behçet’s disease in children — sometimes called paediatric Behçet’s — is uncommon and can be slow to diagnose because doctors often think of more common causes for mouth ulcers and joint pain in children first. The features overlap with adult disease but with some differences.

Presentation in children

• Recurrent mouth ulcers are again the most common first symptom
• Genital ulcers and skin findings often appear later than in adults
• Family history of Behçet’s disease is more often present in childhood-onset cases
• Fevers and gastrointestinal symptoms may be more common at presentation

Diagnosis in children

Children are usually assessed by a paediatric rheumatologist. Specific paediatric criteria (such as the PEDBD classification) have been developed because adult criteria can miss children. The diagnostic workup is similar — clinical pattern, eye examination, blood tests, imaging if needed — but it is interpreted with paediatric reference ranges.

Treatment in children

Treatment principles are the same as in adults but adjusted for age, weight, and growth. Doctors are especially careful to limit long courses of corticosteroids in children because of effects on growth and bone health, and to use immunosuppressants or biologics earlier when needed. EULAR recommendations explicitly discuss adaptation for younger patients.

School and family life

Parents often need to coordinate with schools about absences for appointments and flares, vaccinations, and what to do if the child becomes unwell. With good treatment, most children with Behçet’s grow well, attend school, play sports, and reach typical milestones. A paediatric rheumatologist and, where appropriate, a school counsellor can help with practical plans.

Preventing Complications and Progression

• Stay on treatment, even when you feel well. Many flares happen after medicines are stopped suddenly
• Keep all follow-up appointments, including eye checks, even between flares
• Report new symptoms promptly, particularly eye, neurological, gut, or vascular changes
• Manage cardiovascular risk factors — blood pressure, cholesterol, smoking, weight — because the disease itself places extra strain on blood vessels
• Protect bone health if you are on long-term corticosteroids, with calcium, vitamin D, weight-bearing exercise, and bone density checks when advised
• Stay up to date with appropriate vaccines as discussed with your rheumatologist

When to Seek Urgent Care

Most flares can be managed with planned changes to medicines through your rheumatology team. Some symptoms, however, need urgent assessment because they may signal serious complications:

• Sudden change in vision, severe eye pain, or new floaters or light sensitivity
• New severe headache, weakness, numbness, slurred speech, balance problems, or seizures
• A swollen, painful, hot leg suggesting a deep vein clot
• Sudden chest pain, breathlessness, or coughing up blood
• Severe abdominal pain, vomiting, or blood in the stool
• High fever with feeling unwell, particularly while on immunosuppressants — this may signal infection

If these occur, attend an emergency department and tell the team you have Behçet’s disease and what medicines you are taking.

Frequently Asked Questions

Is Behçet’s disease curable?

Behçet’s disease is not curable at present, but it is treatable. With modern treatment, most people can keep the disease well controlled, prevent organ damage, and live full lives. Many people experience long periods of remission, particularly as years go by.

Is Behçet’s disease genetic?

There is a genetic component — the HLA-B51 gene is associated with the condition — but it is not inherited in a straightforward way. Most people with Behçet’s have no affected family members, and most people with HLA-B51 never develop the disease. The risk to a child of an affected parent is small but slightly higher than in the general population.

Is it the same as Crohn’s disease or lupus?

No, but they can look similar in some ways. Crohn’s disease can cause mouth and gut ulcers, and lupus can cause skin, joint, and mouth symptoms. A rheumatologist sorts these out using the pattern of symptoms, examination, and tests. Sometimes the distinction takes time to become clear.

Will I lose my sight?

Eye involvement is the most worrying long-term complication, but the picture has changed greatly with modern treatment. Prompt recognition of eye flares and current treatments, including biologic medicines for severe disease, have substantially reduced the risk of vision loss. Regular eye checks and quick reporting of eye symptoms are key.

Can stress cause a flare?

Many people notice that flares follow stressful periods, poor sleep, or infections. Stress is unlikely to be the sole cause, but it can be a trigger, and managing stress is a reasonable part of overall self-care.

Can I drink alcohol?

Some medicines used in Behçet’s disease, especially methotrexate, do not mix well with alcohol. Even with other medicines, moderation is sensible. Discuss your specific situation with your doctor.

Can I exercise?

Yes, in most cases. Regular gentle to moderate exercise is good for mood, sleep, joint health, and cardiovascular fitness. During flares, particularly with eye, joint, or vascular involvement, your doctor may advise reducing intensity.

Can women with Behçet’s disease have children?

Yes. Many women with Behçet’s have successful pregnancies. Planning is important because some medicines used in treatment need to be changed before conception. A pre-pregnancy review with your rheumatologist and an obstetrician helps adjust treatment safely.

Is Behçet’s disease contagious?

No. Behçet’s disease is not infectious. Mouth and genital ulcers cannot be passed to others.

How long will I need to take medicines?

Most people need long-term treatment to keep the disease controlled, although the type and dose of medicine can often be reduced over time during periods of remission. Stopping treatment is a decision made with your rheumatologist based on how stable your disease has been and which organs have been involved.

Conclusion

Behçet’s disease is a long-term inflammatory condition that affects each person differently. Although it cannot be cured, today’s treatments — from colchicine and corticosteroids to immunosuppressants and biologic drugs — mean that most people can manage flares, protect their eyes, blood vessels, and other organs, and live their lives well. The combination of an experienced rheumatology team, prompt attention to new symptoms, ongoing follow-up, and self-care builds a strong foundation for the years ahead.

If you have just been diagnosed, give yourself time to absorb the information. Write down your questions for your next appointment, learn what flare patterns look like for you, and build a small support network — family, doctors, and other people with the condition — that you can rely on. Behçet’s disease is a long journey, but it is one many people travel with their health, work, family life, and goals intact.