VKH syndrome

Vogt-Koyanagi-Harada Syndrome Vogt-Koyanagi-Harada (VKH) syndrome is a rare, multisystem autoimmune disease characterized by bilateral, diffuse uveitis, neurological, auditory, and integumentary manifestations. It primarily affects individuals with darker skin pigmentation, such as those of Asian, Hispanic, Middle Eastern, and Native American descent.

Clinical Features

VKH syndrome presents in four distinct phases: prodromal, acute uveitic, convalescent, and chronic recurrent.

Prodromal Phase

The prodromal phase resembles a viral infection, with symptoms such as fever, headache, nausea, and meningismus. Neurological symptoms may include tinnitus, vertigo, and dysacusis.

Acute Uveitic Phase

This phase is marked by bilateral granulomatous uveitis, leading to blurred vision, photophobia, and eye pain. Fundoscopic examination reveals serous retinal detachments and choroidal thickening.

Convalescent Phase

During the convalescent phase, depigmentation of the skin and hair occurs, leading to vitiligo, poliosis, and alopecia. The uveitis subsides, but retinal pigment epithelium changes may persist.

Chronic Recurrent Phase

The chronic recurrent phase involves recurrent episodes of uveitis, which can lead to complications such as cataracts, glaucoma, and subretinal fibrosis.

Pathophysiology

VKH syndrome is believed to be an autoimmune disorder where T-cells target melanocyte-associated antigens. The exact trigger is unknown, but genetic predisposition and environmental factors may play a role.

Diagnosis

Diagnosis is primarily clinical, supported by imaging studies such as optical coherence tomography (OCT) and fluorescein angiography. Cerebrospinal fluid analysis may show pleocytosis during the prodromal phase.

Treatment

The mainstay of treatment is high-dose corticosteroids to control inflammation. Immunosuppressive agents such as azathioprine, cyclosporine, or mycophenolate mofetil may be used for steroid-sparing effects.

Prognosis

With prompt and adequate treatment, the prognosis for visual outcomes is generally good, although some patients may experience chronic complications.

See Also

• Uveitis
• Autoimmune diseases
• Retinal detachment

External Links

• National Organization for Rare Disorders
• PubMed Central Article on VKH

NIH genetic and rare disease info

• NIH info on VKH syndrome

VKH syndrome is a rare disease.