Behcet's disease

Question 1

What is it?

Answer 1

Behçet’s disease is a complex inflammatory condition. It characteristically presents with recurrent oral and genital ulcers. It can also cause inflammation in a number of other areas such as the skin, gastrointestinal tract, lungs, blood vessels, musculoskeletal system and central nervous system. The presentation can vary a lot between patients, with some patients mildly affected and others affected dramatically.

There is a link with the HLA B51 gene. This is a prognostic indicator of severe disease.

Question 2

Differentials?

Answer 2

Mouth ulcers are very common. There is a long list of differentials to mouth ulcers:

Simple aphthous ulcers are very common
Inflammatory bowel disease (particularly Crohn’s disease)
Coeliac disease
Vitamin deficiency (B12, folate or iron)
Herpes simplex ulcers
Hand, foot and mouth disease (coxsackie A virus)
Squamous cell carcinoma

Question 3

Features?

Answer 3

Mouth Ulcers

Patients with Behçet’s disease are expected to get at least 3 episodes of oral ulcers per year. They are painful, sharply circumscribed erosions with a red halo. They occur on the oral mucosa and heals over 2-4 weeks.

Genital Ulcers

Genital ulcers are similar in appearance to the oral ulcers. “Kissing ulcers” are where an ulcer develops on two opposing surfaces so that they are facing each other.

Skin

The skin is very easily inflamed in Behçet’s disease. Particular skin findings in Behçet’s disease are:

Erythema nodosum
Papules and pustules (similar to acne)
Vasculitic type rashes

Eyes

Eye manifestations need emergency review by ophthalmology as they can be sight treating.

Anterior or posterior uveitis
Retinal vasculitis
Retinal haemorrhage

Musculoskeletal System

Morning stiffness
Arthralgia
Oligoarthritis often affecting the knee or ankle. This causes swelling without joint destruction.

Gastrointestinal System

Inflammation and ulceration can occur through the gastrointestinal tract. This tends to affect the:

Ileum
Caecum
Ascending colon

Central Nervous System

Memory impairment
Headaches and migraines
Aseptic meningitis
Meningoencephalitis

Veins

In Behçet’s disease the veins can become inflamed and this can lead to vein thrombosis. Examples of this are:

Budd Chiari syndrome
Deep vein thrombosis
Thrombus in pulmonary veins
Cerebral venous sinus thrombosis

These thrombosis tend to stay in place and don’t embolism as they are related to inflammation in the vessel wall.

Lungs

Pulmonary artery aneurysms can develop. If they rupture this can be fatal.

Question 4

Investigation?

Answer 4

Behçet’s disease is a clinical diagnosis based on the features of the condition. The only particular investigation to be aware of is the pathergy test.

The pathergy test involves using a sterile needle to create a subcutaneous abrasion on the forearm. This is then reviewed 24 – 48 hours later to look for a weal 5mm or more in size. It tests for non-specific hypersensitive in the skin. It is positive in Behçet’s disease, Sweet’s syndrome and pyoderma gangrenosum.

Question 5

Management?

Answer 5

Topical steroids to mouth ulcers (e.g. soluble betamethasone tablets)
Systemic steroids (i.e. oral prednisolone)
Colchicine is usually effective as an anti-inflammatory to treat symptoms
Topical anaesthetics for genital ulcers (e.g. lidocaine ointment)
Immunosuppressants such as azathioprine
Biologic therapy such as infliximab