VKH is more common in Asians, Latinos, Middle Easterners, American Indians, and Mexican Mestizos; it is much less common in Caucasians and in Blacks from sub-Saharan Africa.VKH is associated with a variety of genetic polymorphisms that relate to immune function. For example, t has been associated with human leukocyte antigens (HLA) HLA-DR4 and DRB1/DQA1, copy-number variations of complement component 4, a variant IL-23R locus and with various other non-HLA genes. HLA-DRB1*0405 in particular appears to play an important susceptibility role. Diagnosis
If tested in the prodromal phase, cerebrospinal fluid pleocytosis is found in more than 80% of cases, with mainly lymphocytes. This pleocytosis resolves in about 8 weeks even if chronic uveitis persists.Functional tests may include electroretinogram and visual field testing. Diagnostic confirmation and an estimation of disease severity may involve imaging tests such as retinography, fluorescein or indocyanine green angiography, optical coherence tomography and ultrasound. For example, indocyanine green angiography may detect continuing choroidal inflammation in the eyes without clinical symptoms or signs. Ocular MRI may be helpful and auditory symptoms should undergo audiologic testing. Histopathology findings from eye and skin are discussed by Walton.The diagnosis of VKH is based on the clinical presentation; the diagnostic differential is extensive, and includes sympathetic ophthalmia, sarcoidosis, primary intraocular B-cell lymphoma, posterior scleritis, uveal effusion syndrome, tuberculosis, syphilis, and multifocal choroidopathy syndromes.
Vogt–Koyanagi–Harada disease (VKH) is a multisystem disease of presumed autoimmune cause that affects melanin-pigmented tissues. The most significant manifestation is bilateral, diffuse uveitis, which affects the eyes. VKH may variably also involve the inner ear, with effects on hearing, the skin, and the meninges of the central nervous system. Signs and symptoms
Overview
The disease is characterised by bilateral diffuse uveitis, with pain, redness and blurring of vision. The eye symptoms may be accompanied by a varying constellation of systemic symptoms, such as auditory (tinnitus, vertigo, and hypoacusis), neurological (meningismus, with malaise, fever, headache, nausea, abdominal pain, stiffness of the neck and back, or a combination of these factors; meningitis, CSF pleocytosis, cranial nerve palsies, hemiparesis, transverse myelitis and ciliary ganglionitis), and cutaneous manifestations, including poliosis, vitiligo, and alopecia. The vitiligo often is found at the sacral region. Phases
The sequence of clinical events in VKH is divided into four phases - prodromal, acute uveitic, convalescent, and chronic recurrent.The prodromal phase may have no symptoms, or may mimic a nonspecific viral infection, marked by flu-like symptoms that typically last for a few days. Fever, headache, nausea, meningismus, dysacusia (discomfort caused by loud noises or a distortion in the quality of the sounds being heard), tinnitus, and/or vertigo may occur. Eye symptoms can include orbital pain, photophobia, and tearing. The skin and hair may be sensitive to touch. Cranial nerve palsies and optic neuritis are uncommon.The acute uveitic phase occurs a few days later and typically lasts for several weeks.