Vogt-Koyanagi-Harada disease

Vogt-Koyanagi-Harada (VKH) Disease

Vogt-Koyanagi-Harada (VKH) disease is a rare, systemic autoimmune disorder that primarily affects the eyes, skin, hair, and central nervous system. It is characterized by inflammation of these areas, particularly the eyes, leading to vision problems and other systemic symptoms.

Cause

VKH disease is believed to occur when the body's immune system mistakenly attacks melanocytes, the cells responsible for producing pigment (melanin) in the skin, eyes, hair, and inner ear. The exact cause of this autoimmune response is not fully understood, but genetic factors, environmental triggers (such as viral infections), and immune system dysregulation may play a role.

VKH is more commonly seen in individuals with certain genetic predispositions, particularly those of Asian, Hispanic, or Native American descent.

Symptoms

VKH disease typically develops in stages, and its symptoms can affect various systems in the body, with the most significant effects on vision and the skin. The disease can cause a variety of symptoms, including:

1. Ocular (Eye) Symptoms:
   • Uveitis: Inflammation of the uvea (the middle layer of the eye), which can lead to redness, pain, light sensitivity, and blurred vision.
   • Retinal Detachment: Inflammation in the retina can lead to swelling or detachment, resulting in vision loss.
   • Sunset Glow Fundus: A characteristic eye finding where the fundus (the back of the eye) appears to have a sunset-like glow due to inflammation.
   • Vision Loss: If untreated, VKH can lead to permanent vision loss.
2. Skin Symptoms:
   • Vitiligo: Loss of pigmentation in the skin, leading to depigmented patches.
   • Poliosis: Premature graying of the hair, particularly in the eyebrows or eyelashes.
   • Alopecia: Hair loss, typically affecting the scalp, which can lead to patchy or complete baldness in some cases.
3. Neurological Symptoms:
   • Meningeal Inflammation: Inflammation of the meninges (the membranes covering the brain and spinal cord), causing headache, neck stiffness, and fever.
   • Tinnitus: Ringing in the ears, often associated with inner ear involvement.
   • Vertigo and Hearing Loss: Due to inflammation affecting the inner ear structures.
4. Systemic Symptoms:
   • Fever and generalized fatigue are common early symptoms, especially in the acute stage of the disease.
   • Muscle pain and joint stiffness may also occur.

Diagnosis

The diagnosis of VKH disease is made based on clinical findings, medical history, and a combination of tests. There is no single test to confirm the disease, but doctors typically use the following diagnostic approaches:

1. Eye Examination:
   • A detailed eye exam using slit-lamp microscopy and fundoscopy (examination of the retina) may reveal characteristic signs of uveitis and retinal changes (e.g., sunset glow fundus).
2. Imaging:
   • Fluorescein angiography: A technique to assess the blood vessels in the retina, which can show signs of inflammation.
   • Optical coherence tomography (OCT): A non-invasive imaging test that can evaluate retinal thickness and any fluid accumulation or damage.
3. Blood Tests:
   • Blood tests to rule out other autoimmune diseases and infections.
   • HLA-DR4 and HLA-DRw53 are genetic markers often associated with VKH disease, though they are not diagnostic by themselves.
4. Neurological Testing:
   • MRI or CT scans may be used if there are neurological symptoms, such as meningitis or inflammation of the brain.

Treatment

The goal of treatment for VKH disease is to control inflammation, prevent damage to the eyes and other organs, and manage symptoms. Treatment typically involves:

1. Corticosteroids:
   • Oral steroids (e.g., prednisone) are the mainstay of treatment for the acute phase to reduce inflammation. Steroid eye drops may also be used for ocular inflammation.
   • Intravitreal steroids may be used in severe cases where the inflammation does not respond to oral medications.
2. Immunosuppressive Medications:
   • If corticosteroids alone are not effective or if long-term steroid use is required, additional immunosuppressive drugs (e.g., methotrexate, azathioprine, or mycophenolate mofetil) may be used to control the autoimmune response.
   • Biologic agents such as TNF-alpha inhibitors or rituximab may be considered in resistant cases.
3. Vision Support:
   • Regular monitoring of eye health, including retinal function, is essential to manage and prevent vision loss. Early treatment can help reduce the risk of permanent damage to the retina and optic nerve.
4. Symptomatic Treatment:
   • Pain relief, fever management, and anti-inflammatory medications are often used to alleviate systemic symptoms like headache and joint pain.

Prognosis

The prognosis of VKH disease varies, depending largely on how early the condition is diagnosed and treated. With prompt and appropriate treatment, many individuals can maintain vision and experience significant improvement in symptoms. However, if left untreated, VKH disease can lead to permanent vision loss, significant neurological damage, and systemic complications.

Some individuals may experience relapses, and long-term follow-up with an ophthalmologist and other specialists is often necessary to manage the disease.

‍