Vogt-Koyanagi-Harada (VKH) syndrome is a rare systemic disease involving various melanocyte-containing organs. Bilateral panuveitis associated with cutaneous, neurologic, and auditory abnormalities are manifestations of this inflammatory granulomatous disorder. VKH syndrome was first noted in the 10th century by a Persian ophthalmologist, Ali Ibn Isa, who described a case of poliosis associated with ocular inflammation. This association was reported again in 1873 by Schenkl, in 1892 by Hutchinson, and in 1906 by Vogt. In 1926, Haradadescribed a patient with idiopathic uveitis affecting the posterior segment, with retinal detachment and meningeal irritation. Koyanagi reported similar cases in 1929. Babel, in 1932, suggested that symptoms of the disorder described by Vogt, Koyanagi, and Harada were manifestations of the same single entity, referred to as Vogt-Koyanagi-Harada syndrome or uveoencephalitis.
Clinical and experimental data continue to support an immunologic etiology. An autoimmune reaction seems to be directed against an antigenic component shared by uveal, dermal, and meningeal melanocytes. The exact target antigen has not been identified, but possible candidates include tyrosinase- or tyrosinase-related proteins, an unidentified 75-kd protein obtained from cultured human melanoma cells (G-361), and S-100 protein. Evidence suggests that Th1 and Th17 subsets of T cells together with cytokines interleukin (IL)–23 and IL-17 are likely involved in the initiation and maintenence of the inflammatory process.
VKH syndrome can be associated with other autoimmune disorders such as autoimmune polyglandular syndrome,hypothyroidism, Hashimoto thyroiditis, diabetes mellitus,Guillain-Barré syndrome, and IgA nephropathy.
Single reports of patients developing VKH syndrome after cutaneous injury have been noted, as well as 2 cases of this condition occurring after BCG therapy for melanoma and 1 case following surgery of metastatic malignant melanoma. Case reports indicate that even an indirect trauma in melanocyte-containing tissue may induce an inflammatory response within the eye, with Vogt-Koyanagi-Harada disease following a closed head trauma. Cases of this syndrome were reported to be linked to malignant lymphoma.
Immunologic analysis of cerebrospinal fluid (CSF) lymphocytes in VKH syndrome and studies of human uveal melanocytes show that uveal pigment can stimulate lymphocyte cultures from patients with VKH syndrome. Lymphocytes of peripheral blood and CSF from these patients may reveal in vitro cytotoxicity against allogenic melanoma cells.
Circulating antibodies against a retinal photoreceptor region have been detected in patients with this disorder.
The possibility that VKH syndrome has an autoimmune pathogenesis is supported by the statistically significant frequency of HLA-DR4, an antigen commonly associated with other autoimmune diseases. VKH syndrome has been closely associated with HLA-B54, HLA-DR4, and HLA-DR53 in Japanese patients ; with HLA-DR4, HLA-DRw53, and HLA-DQw3 in subjects of Native American ancestry; with HLA-DR1 and HLA-DR4 in Hispanic patients living in southern California; and with HLA-DR4 and HLA-DQw7 in Chinese patients. HLA-DR4 also was found to be significantly related to VKH syndrome in white Europeans, specifically in Italian patients. These findings confirm the possibility of immunogenic predisposition and the decisive role of HLA-DR4 antigen in the development of the disease.
Data indicate that patients with VKH syndrome are sensitized to melanocyte epitopes and display a peptide-specific Th1 cytokine response. Patients bearing HLA-DRB1*0405 recognize a broader melanocyte-derived peptide repertoire, so the presence of this allele increases susceptibility to the development of VKH disease. In a group of French VKH syndrome DRB1*04-positive patients, the HLA-DRB1*0405 subtype was found in 71%.
A recent study revealed that a decreased vitamin D-3 level has been associated with active intraocular inflammation in VKH syndrome patients.
Pathophysiology
The etiologic and pathogenic factors in VKH syndrome remain unclear. The clinical course of VKH syndrome with an influenzalike episode suggests a viral or postinfectious origin. Some studies invoke a possible role of Epstein-Barr virus reactivation in this disease.Although a viral cause has been proposed, no virus has been isolated or cultured from patients with VKH syndrome. Morris and Schlaegel found viruslike inclusion bodies in the subretinal fluid of a patient with VKH syndrome.Clinical and experimental data continue to support an immunologic etiology. An autoimmune reaction seems to be directed against an antigenic component shared by uveal, dermal, and meningeal melanocytes. The exact target antigen has not been identified, but possible candidates include tyrosinase- or tyrosinase-related proteins, an unidentified 75-kd protein obtained from cultured human melanoma cells (G-361), and S-100 protein. Evidence suggests that Th1 and Th17 subsets of T cells together with cytokines interleukin (IL)–23 and IL-17 are likely involved in the initiation and maintenence of the inflammatory process.
VKH syndrome can be associated with other autoimmune disorders such as autoimmune polyglandular syndrome,hypothyroidism, Hashimoto thyroiditis, diabetes mellitus,Guillain-Barré syndrome, and IgA nephropathy.
Single reports of patients developing VKH syndrome after cutaneous injury have been noted, as well as 2 cases of this condition occurring after BCG therapy for melanoma and 1 case following surgery of metastatic malignant melanoma. Case reports indicate that even an indirect trauma in melanocyte-containing tissue may induce an inflammatory response within the eye, with Vogt-Koyanagi-Harada disease following a closed head trauma. Cases of this syndrome were reported to be linked to malignant lymphoma.
Immunologic analysis of cerebrospinal fluid (CSF) lymphocytes in VKH syndrome and studies of human uveal melanocytes show that uveal pigment can stimulate lymphocyte cultures from patients with VKH syndrome. Lymphocytes of peripheral blood and CSF from these patients may reveal in vitro cytotoxicity against allogenic melanoma cells.
Circulating antibodies against a retinal photoreceptor region have been detected in patients with this disorder.
The possibility that VKH syndrome has an autoimmune pathogenesis is supported by the statistically significant frequency of HLA-DR4, an antigen commonly associated with other autoimmune diseases. VKH syndrome has been closely associated with HLA-B54, HLA-DR4, and HLA-DR53 in Japanese patients ; with HLA-DR4, HLA-DRw53, and HLA-DQw3 in subjects of Native American ancestry; with HLA-DR1 and HLA-DR4 in Hispanic patients living in southern California; and with HLA-DR4 and HLA-DQw7 in Chinese patients. HLA-DR4 also was found to be significantly related to VKH syndrome in white Europeans, specifically in Italian patients. These findings confirm the possibility of immunogenic predisposition and the decisive role of HLA-DR4 antigen in the development of the disease.
Data indicate that patients with VKH syndrome are sensitized to melanocyte epitopes and display a peptide-specific Th1 cytokine response. Patients bearing HLA-DRB1*0405 recognize a broader melanocyte-derived peptide repertoire, so the presence of this allele increases susceptibility to the development of VKH disease. In a group of French VKH syndrome DRB1*04-positive patients, the HLA-DRB1*0405 subtype was found in 71%.
A recent study revealed that a decreased vitamin D-3 level has been associated with active intraocular inflammation in VKH syndrome patients.
Epidemiology
Frequency
United States
VKH syndrome is rare. No precise data are available regarding frequency of the disease.International
VKH syndrome is rare but widely distributed.Mortality/Morbidity
VKH syndrome is not associated with mortality. Acute disturbances in hearing and vision may occur, and the cutaneous changes may be permanent.Race
VKH syndrome occurs more frequently in individuals with darker pigmentation (eg, persons of Asian, Native American, Latin American, or black heritage). VKH syndrome is one of the most common forms of uveitis among pigmented races. The manifestations of VKH syndrome in whites resemble those in the Japanese population. However, cutaneous signs are much more rarer.Sex
Women appear to be affected with VKH syndrome more frequently than men.Age
The onset of VKH syndrome has been reported to range from 3-89 years, with a maximum frequency in the thirties. Although often unrecognized, VKH syndrome may affect children.History
VKH syndrome is usually preceded by a prodromal stage of nonspecific symptoms including headache, increased sensitivity to touch of the hair and skin, vertigo, nausea, nuchal rigidity, vomiting, and low-grade fever that may last a few days. Patients usually initially present to an ophthalmologist for ocular problems, including sudden loss of vision, ocular pain, and photophobia. Hearing disturbances and dizziness may be present. After weeks or months, most patients notice cutaneous signs (eg, hair loss, poliosis, vitiligo).
2. No clinical or laboratory evidence suggestive of other ocular disease entities
3. Bilateral ocular involvement - (a) or (b) must be met, depending on the stage of disease when the patient is examined, based on early and late manifestations below.
Early manifestations of the disease
(1) There must be evidence of a diffuse choroiditis (with or without anterior uveitis, vitreous inflammatory reaction, or optic disk hyperemia), which may manifest as one of the following: (a) focal areas of subretinal fluid or (b) bullous serous retinal detachments.
(2) With equivocal fundus findings, both of the following must be present as well: (a) focal areas of delay in choroidal perfusion, multifocal areas of pinpoint leakage, large placoid areas of hyperfluorescence, pooling within subretinal fluid, and optic nerve staining (listed in order of sequential appearance) by fluorescein angiography and and (b) diffuse choroidal thickening, without evidence of posterior scleritis by ultrasonography.
Late manifestations of the disease
(1) History suggestive of the prior presence of findings from (3)(a) and either both (2) and (3) below or multiple signs from (3)
(2) Ocular depigmentation: Either (a) sunset glow fundus or (b) Sugiura sign is sufficient.
(3) Other ocular signs may include (a) nummular chorioretinal depigmented scars, (b) retinal pigment epithelium clumping and/or migration, or (c) recurrent or chronic anterior uveitis.
4. Neurological/auditory findings (may have resolved by time of examination) - Meningismus (malaise, fever, headache, nausea, abdominal pain, stiffness of the neck and back, or a combination of these factors; headache alone is not sufficient to meet the definition of meningismus) or Tinnitus, or CSF pleocytosis
5. Integumentary findings (not preceding the onset of CNS or ocular disease) - Alopecia, or Poliosis, or Vitiligo
Complete VKH disease is if criteria 1-5 are present.
Incomplete VKH disease is if criteria 1-3 and either 4 or 5 are present.
Probable VKH disease is isolated ocular disease; criteria 1-3 must be present.
The classic course of VKH syndrome consists of the following 3 phases:
Physical
The American Uveitis Society developed the first diagnostic criteria for VKH Syndrome in 1978. In addition to an absence of prior ocular trauma or surgery, at least 3 of the following 4 criteria should be met to confirm the diagnosis of VKH syndrome:- Bilateral chronic iridocyclitis
- Posterior uveitis, which may include exudative retinal detachment, optic nerve swelling, or atrophy of the retinal pigment epithelium
- Cerebrospinal fluid pleocytosis or evidence of tinnitus, dysacusis, headache or meningismus, or cranial nerve involvement
- Cutaneous findings of vitiligo, alopecia, or poliosis
Criteria for VKH syndrome (1-5)
1. No history of penetrating ocular trauma or surgery preceding the initial onset of uveitis2. No clinical or laboratory evidence suggestive of other ocular disease entities
3. Bilateral ocular involvement - (a) or (b) must be met, depending on the stage of disease when the patient is examined, based on early and late manifestations below.
Early manifestations of the disease
(1) There must be evidence of a diffuse choroiditis (with or without anterior uveitis, vitreous inflammatory reaction, or optic disk hyperemia), which may manifest as one of the following: (a) focal areas of subretinal fluid or (b) bullous serous retinal detachments.
(2) With equivocal fundus findings, both of the following must be present as well: (a) focal areas of delay in choroidal perfusion, multifocal areas of pinpoint leakage, large placoid areas of hyperfluorescence, pooling within subretinal fluid, and optic nerve staining (listed in order of sequential appearance) by fluorescein angiography and and (b) diffuse choroidal thickening, without evidence of posterior scleritis by ultrasonography.
Late manifestations of the disease
(1) History suggestive of the prior presence of findings from (3)(a) and either both (2) and (3) below or multiple signs from (3)
(2) Ocular depigmentation: Either (a) sunset glow fundus or (b) Sugiura sign is sufficient.
(3) Other ocular signs may include (a) nummular chorioretinal depigmented scars, (b) retinal pigment epithelium clumping and/or migration, or (c) recurrent or chronic anterior uveitis.
4. Neurological/auditory findings (may have resolved by time of examination) - Meningismus (malaise, fever, headache, nausea, abdominal pain, stiffness of the neck and back, or a combination of these factors; headache alone is not sufficient to meet the definition of meningismus) or Tinnitus, or CSF pleocytosis
5. Integumentary findings (not preceding the onset of CNS or ocular disease) - Alopecia, or Poliosis, or Vitiligo
Complete VKH disease is if criteria 1-5 are present.
Incomplete VKH disease is if criteria 1-3 and either 4 or 5 are present.
Probable VKH disease is isolated ocular disease; criteria 1-3 must be present.
The classic course of VKH syndrome consists of the following 3 phases:
- In the meningoencephalitis phase, the degree of neurologic symptoms may vary. Generalized muscle weakness, hemiparesis, hemiplegia, dysarthria, and aphasia have been reported. Most of the neurologic symptoms have been directly attributed to changes in CSF (eg, pleocytosis, increased pressure, protein levels), inflammatory arachnoiditis, or resulting subarachnoidal adhesions. Mental changes ranging from mild confusion to psychosis may occur.
- The ophthalmic-auditory phase is characterized by common features such as decreased visual acuity, eye pain, eye irritation, and loss of vision. Dysacusis (usually bilateral) and tinnitus develop in 50% of patients.
- The convalescent phase is characterized by cutaneous signs developing after uveitis begins to subside, usually within 3 months from the onset of disease. Although cutaneous signs typically occur several weeks to months after the onset of ocular inflammation, skin changes have sometimes been observed many years before uveitis appeared. Pigmentary changes tend to be permanent. Poliosis, which occurs in 90% of patients, involves the eyebrows and eyelashes and, occasionally, the scalp and body hair. Poliosis affects 50% of patients and usually appears after the onset of alopecia, which may be patchy or diffuse. Vitiligo manifests in 63% of patients and is often symmetric. Most patients have perilimbal vitiligo (Sugiura sign). Atypical variants of vitiligo with inflammatory raised borders and plaque-type inflammatory erythema have also been reported. Halo nevi may be present.
Causes
The cause of VKH syndrome is unknown, but a viral factor has been suggested in the pathogenesis. An autoimmune reaction to melanocytes with the involvement of T-cell–mediated cytotoxicity and apoptosis is postulated. Although almost all instances of VKH syndrome are sporadic, and familial cases are rare, some authors suggest that the condition may be inherited, probably as an autosomal recessive trait. Numerous data demonstrate the association of HLA-DR4 antigen and VKH syndrome in different racial groups. According to some studies, the major factor contributing to susceptibility for the disease is presence of the DRB*0405 allele.Differentials
- Alezzandrini Syndrome
- Alopecia Areata
- Piebaldism
- Vitiligo
Laboratory Studies
- For quick diagnosis and early treatment, Vogt-Koyanagi-Harada (VKH) syndrome requires a multidisciplinary management strategy involving dermatologists and ophthalmologists.
- Perform neurologic examination with lumbar puncture to detect associated abnormalities.
- Detailed CSF cell analysis is necessary. Changes in the CSF include pleocytosis with the presence of melanin-laden macrophages (specific for the syndrome and helpful in confirming the diagnosis), increased protein levels, and increased pressure.
Imaging Studies
- Standardized A-scan and contact B-scan echography, performed by ophthalmologist
- Orbital MRI
- Brain MRI
Procedures
- Perform fluorescein angiography, which shows multiple hypofluorescent areas in the retina at the level of the retinal pigment epithelium.
- Perform indocyanine green choroidal angiography.
- Audiometry may reveal sensorineural hearing loss.
Histologic Findings
A skin biopsy specimen taken a month after the onset of VKH syndrome ocular symptoms will likely reveal a mononuclear infiltrate concentrated in the area of hair follicles and sweat glands, consisting mostly of T lymphocytes with a small number of B cells. In depigmented skin, the absence of melanin, as anticipated in vitiligo, can be noted. Vasodilatation in the dermis, pigment-laden macrophages, and a lymphocytic infiltrate have also been described.
Medical Care
- For pigmentary changes with Vogt-Koyanagi-Harada (VKH) syndrome, treatment options mirror those for vitiligo.
- For eye inflammatory changes, treatment includes systemic corticosteroids, with an average initial dose of 80-100 mg of oral prednisone per day. Early, aggressive use of systemic corticosteroids and a gradual tapering of drug dosage for 6 months after presentation are recommended to prevent progression and development of complications. Some authors recommend pulse corticosteroid therapy.
- Topical and periocular corticosteroids are used. If systemic medications are not effective,subtenon injections may be considered before intraocular treatment modalities.
- Cycloplegic-mydriatic eye drops are used symptomatically.
Surgical Care
- Surgical therapy for glaucoma is necessary in some patients. Surgical intervention includes laser iridotomy, surgical iridectomy, and trabeculectomy.
Consultations
Ophthalmologists and neurologists must be consulted.
Medication Summary
The goals of pharmacotherapy are to reduce morbidity and to prevent complications.
Corticosteroids
Class Summary
Have anti-inflammatory properties and cause profound and varied metabolic effects. Modify the body's immune response to diverse stimuli.
Prednisone (Deltasone, Orasone)
Immunosuppressive agents
Class Summary
Have antiproliferative and immunosuppressive effects.
Pediatric Dosing & Uses
Safety and efficacy not established; however used as adults (off label)Dosing Forms & Strengths
tablet- 50mg
powder for injection- 100mg/vial
oral suspension- 50mg/mL
Pregnancy & Lactation
Pregnancy Category: D
Lactation: excreted at low levels in breast milk/not recommended
Pharmacology
Absorption: good (PO)
Half-Life: 5 hr
Duration: variable
Plasma Concentration: <1 mcg/mL
Protein Bound: 30%
Metabolism: liver
Metabolites: mercaptopurine, 6-thiouric acid
Dialyzable: partially
Pharmacogenomics
Azathioprine is a prodrug and extensively metabolized to the active metabolite 6-mercaptopurine
6-mercaptopurine is activated further by guanine phosphoribosyltransferase (HGPRT) to form thioinosine monophosphate (TIMP) and by kinase enzymatic pathways to form active 6-thioguanine nucleotides
Thiopurine S-methyltransferase (TPMT) inactivates 6-mercaptopurine
Although complete TPMT deficiency is rare in the general population (0.3%), TPMT screening should be performed prior to administration in all patients prescribed azathioprine or 6-mercaptopurine
With TPMT deficiency, a larger proportion of 6-mercaptopurine is converted to the cytotoxic 6-thioguanine nucleotide analogues, which can lead to bone marrow toxicity and myelosuppression
Alleles associated with decreased TPMT enzymatic activity are TPMT*2, TPMT*3A, and TPMT*3C
IV & IM Information
IV Incompatibilities
Stable in neutral or acid solutions, but in alkaline solns is hydrolyzed to mercaptopurine
IV Administration
Can be administered IVP over 5 min at a concentration not exceeding 10 mg/mL
Can be further diluted with NS or D5W & administered by intermittent infusion over 30-60 min (usual) but infusions ranging from 5 min to 8 hr have been done
Storage
Store powder at room temp protected from light
Reconstituted soln is stable for 2 wk at room temp (25°C); may be less stable under refrigeration
Use within 24 hr since no preservatives