Uveodermatologic Syndrome (UDS, VKH)

Liaison: Marie Monaco

Uveodermatological Syndrome (UDS) is an immune-mediated canine disease characterized by inflammation of the eye, depigmentation of skin and whitening of hair. Morbidity is related primarily to the eye inflammation, which can result in secondary ophthalmological disorders that lead to blindness. Treatment involves both topical and systemic immunosuppression.

Uveodermatological Syndrome is similar to the human Vogt-Koyanagi-Haradi Syndrome (VKH), was first described in 1977 [1]. Human VKH is characterized by uveitis (inflammation of the eye), poliosis (whitening of hair), vitiligo (depigmentation of skin) and a variety of neurological symptoms. Unlike VKH, however, UDS does not usually present with neurological symptoms. Because of the similarity of the two entities, UDS is sometimes referred to as VKH-like Syndrome or simply VKH. Although generally considered to be more common in Northern breeds, such as Akitas, Siberians and Samoyeds, there have been reports of the disease in a wide range of breeds, including the Dachshund [2] and Brazilian Fila dog [3].

Signs and Symptoms

UDS often presents with bilateral panuveitis, which is generally characterized by red and cloudy eyes, with tearing and squinting, as well as varying degrees of localized vitiligo (nose, lips, eye rims and, less commonly, footpads and anus). Generalized vitiligo has been reported in two cases [2]. The eye inflammation can cause secondary complications, such as retinal detachment, cataracts and glaucoma. Blindness can result from these complications. The syndrome is most often diagnosed by a veterinary ophthalmologist and requires life long medical therapy.

Causes

UDS (and VKH) is thought to be caused by the inappropriate production of antibodies directed against melanocytes (pigment-producing cells), although viral infection cannot be ruled out as a cause of the disease [4]. A recent report describes the association of UDS in American Akitas with an increased frequency of the DQA1*00201 allele, suggesting a genetic component to the disease [5].

Risk Factors

Most reported cases of UDS involve Akitas (~80%) suggesting a predisposition in this breed. The age range reported is from 6 months to 6 years, with a slightly increased incidence in males [2].

Diagnostic Tests

Diagnosis can generally be made on the basis of a microscopic eye examination; a skin biopsy, usually from an affected area such as the nose, can also be done, although it is often not necessary to make the diagnosis.

Treatment Guidelines

Note: Treatment of animals should only be performed by a licensed veterinarian. Veterinarians should consult the current literature and current pharmacological formularies before initiating any treatment protocol.

Morbidity in the case of UDS results from the eye involvement, which can lead to blindness if left untreated. Treatment consists of immunosuppression using a combination of systemic and topical anti-inflammatory medications [2]. Dosages and scheduling varies, with the goal being to start off using a high dose during the induction phase, and gradually tapering off to a regimen that keeps the disease in remission while limiting the potential side effects of long term treatment.

References

[1] S.T. Asakura, K.; Onishi, T., Vogt-Koyanagi-Harada syndrome (uveitis diffusa acuta) in the dog, Japanese Journal of Veterinary Medicine 673 (1977) 445-455. (unable to rate)

[2] H.D.D. Herrera, A. G., Uveodermatological syndrome (Vogt-Koyanaga-Harada-like syndrome) with generalized depigmentation in a Dachshund, Veterinary Ophthalmology 1 (1998) 47-51. 2 bones

[3] J.L. Laus, M.G. Sousa, V.P. Cabral, F.V. Mamede, M. Tinucci-Costa, Uveodermatologic syndrome in a Brazilian Fila dog, Veterinary Ophthalmology 7 (2004) 193-196. 2bones

[4] W.J. Carter, S.M. Crispin, D.J. Gould, M.J. Day, An immunohistochemical study of uveodermatologic syndrome in two Japanese Akita dogs, Veterinary Ophthalmology 8 (2005) 17-24. 2bones

[5] J.M. Angles, T.R. Famula, N.C. Pedersen, Uveodermatologic (VKH-like) syndrome in American Akita dogs is associated with an increased frequency of DQA1*00201, Tissue Antigens 66 (2005) 656-665. 2 bones