AKT · Musculoskeletal/Vasculitis, PMR & GCAlow yield

Behçet's disease

Variable-vessel vasculitis — recurrent oral & genital ulceration with multisystem inflammation (HLA-B51)

Overview

A chronic relapsing multisystem inflammatory disorder classed as a variable-vessel vasculitis (it can affect vessels of any size, arterial and venous). It is most common in young adults from the eastern Mediterranean and Silk Road regions and is associated with HLA-B51. The hallmark is recurrent painful oral AND genital ulceration, with anterior uveitis, skin lesions, and a positive pathergy test.

Recognise

Recurrent painful ORAL and GENITAL ulcers (the classic combination); relapsing-remitting course
Anterior uveitis (sight-threatening), skin lesions (erythema nodosum, papulopustular), arthritis
Pathergy (exaggerated skin reaction — a sterile pustule — to a needle prick); thrombophlebitis/venous and arterial thrombosis; neuro- and GI involvement

Red flags

Posterior uveitis/retinal vasculitis or neuro-Behçet's → sight- or life-threatening → urgent specialist immunosuppression
Major vessel involvement (arterial aneurysm, venous thrombosis) → specialist care

Differentials & how to tell them apart

Reactive arthritispost-infectious, with urethritis/conjunctivitis; no recurrent genital ULCERS or pathergy

Inflammatory bowel diseaseoral ulcers + GI symptoms — but Behçet's has genital ulcers + pathergy + uveitis

SLE / herpes / aphthous ulcersdifferent serology/virology; isolated aphthous ulcers lack the genital/ocular/pathergy features

Investigations

Clinical diagnosis (international criteria: recurrent oral ulceration plus two of genital ulcers, eye lesions, skin lesions, or a positive pathergy test); HLA-B51 supports it; pathergy test; inflammatory markers; imaging for vascular/neurological involvement.

Management

Colchicine/topical steroid for mucocutaneous disease; systemic immunosuppression for organ involvement

1Diagnose clinically (recurrent oral ulcers + genital ulcers/eye/skin/pathergy). Treat mucocutaneous and joint disease with topical corticosteroids and colchicine.Gate: Ocular (posterior uveitis/retinal vasculitis), neurological, vascular or GI involvement → systemic corticosteroids + immunosuppression (or anti-TNF) — these are organ/sight/life-threatening and not for topical therapy alone.
2Severe or refractory disease → anti-TNF or interferon; manage major-vessel and neurological disease in specialist centres.

Topical corticosteroids for mucocutaneous ulcers; colchicine for ulcers/erythema nodosum/arthritis — first-line for mucocutaneous and joint disease

Systemic corticosteroids + immunosuppressants (azathioprine, ciclosporin) — for ocular, neurological, vascular or GI involvement

Anti-TNF / interferon — for severe or refractory disease (especially sight-threatening uveitis)

Manage thrombosis — immunosuppression treats the inflammatory thrombus; specialist-led

Key points

Recurrent ORAL + GENITAL ulcers + anterior uveitis + positive pathergy in a young adult (HLA-B51, eastern-Mediterranean/Silk-Road origin) = Behçet's → colchicine/topical steroid for mucocutaneous disease, systemic immunosuppression for eye/neuro/vascular/GI involvement.

Monitor & prognosis

Disease activity, ocular review, organ involvement; immunosuppression safety.

Relapsing-remitting; ocular, neurological and vascular involvement drive morbidity.

Source: EULAR Behçet's; cross-ref ophthalmology (uveitis)