Uveodermatologic syndrome

From Dog
Uveodermatologic syndrome in a 4-year-old, female Samoyed. Note the uveitis (miosis, iritis and diffuse corneal oedema) and vitiligo (palpebral dyspigmentation)[1]
Nasal dyspigmentation and mucosal ulceration associated with uveodermatologic syndrome[1]

Uveodermatologic syndrome (UVD; Vogt-Koyanagi-Harada syndrome) is an immune-mediated disease marked by depigmentation of the periocular region, lips and nose in association with severe anterior uveitis[2].

The disease is thought to develop as a consequence of autoimmune attack against melanocytes of neural crest (skin, hair, anterior uvea) and neuroectodermal (retina) origin[3]. Skin lesions appear to be mediated by T cells and macrophages (Th1 immunity), whereas the ocular lesions are more consistent with a B cell and macrophage response (Th2 immunity)[4].

The highest incidence of the disease is seen in the Akita, with this breed making up about 80% of the case reports[5]. The syndrome is also seen in the Siberian Husky, Irish Setter, Dachshund, Fox terrier, Shetland Sheepdog, Saint Bernard, Old English Sheepdog, Chow Chow, Samoyed and Fila Brasileiro breeds[6][7]. A case has also been reported in a family of Portuguese Water Dogs with primary uveodermatologic lymphoma[8].

It is believed that exposure to ultraviolet radiation may exacerbate the symptoms associated with this condition[9].

Although the disease is characterized by recurrent bilateral anterior uveitis and heterochromia, other associated symptoms can also occur such as blepharospasm, blepharitis, conjunctival hyperemia, diffuse corneal edema, peripheral bullous retinal detachment and secondary ocular hypertension[10].

Despite treatment, some dogs will deteriorate, with progressive panuveitis, iris bombé, secondary glaucoma[11] and crusting of the nasal planum and ulceration of buccal lesions. In these cases, pain, pruritus and lymphadenopathy may be observed.

Often leukotrichia, whitening of the hair, will be seen and some dogs may be so severely affected that they have generalized depigmentation of the skin and hair or alopecia[12].

Diagnosis is usually based on histopathological examination of skin biopsies and eyes, with characteristic lichenoid interface dermatitis and pigmentary incontinence within the dermis.

A differential diagnosis would include uveodermatologic lymphoma, erythema multiforme, lupus erythematosus, pemphigus, vitiligo and leishmaniasis.

In some affected dogs, bilateral enucleation is required, but most respond to treatment with oral and topical (subconjunctival) prednisolone (1 – 3 mg/kg, PO, q 12 – 24 hours[12]), topical indomethacin (1%) and oral azathioprine (1.5 – 2.5 mg/kg PO q 48 – 72 hours)[13].

A topical cycloplegic, such as 1% atropine ophthalmic solution, may be applied to the eyes every 6 to 24 hours, to effect, if the pupil is miotic[12]

Animals with UVD may need life-long therapy depending on the response to chemotherapy.

References

  1. 1.0 1.1 Uni of Lisboa
  2. Müller RS et al (1992) The uveodermatologic syndrome in dogs. Tierarztl Prax 20(6):632-636
  3. Sigle KJ et al (2006) Unilateral uveitis in a dog with uveodermatologic syndrome. J Am Vet Med Assoc 228:543–548
  4. Carter WJ et al (2005) An immunohistochemical study of uveodermatologic syndrome in two Japanese Akita dogs. Vet Ophthalmol 8(1):17-24
  5. Angles JM et al (2005) Uveodermatologic (VKH-like) syndrome in American Akita dogs is associated with an increased frequency of DQA1*00201. Tissue Antigens 66:656–665
  6. Laus JL et al (2004) Uveodermatologic syndrome in a Brazilian Fila dog. Vet Ophthalmol 7(3):193-196
  7. Ettinger SJ & Feldman EC (1989) Textbook of Veterinary Internal Medicine. 3rd ed. St Louis: Saunders Elsevier. p:76
  8. Escanilla N et al (2012) Uveodermatologic lymphoma in two young related Portuguese water dogs. Vet Ophthalmol 15(5):345-350
  9. Tilley LP & Smith FW (2004) The Five Minute Veterinary Consult. 3rd ed. Baltimore: Lippincott. p:1319
  10. Blackwood SE et al (2011) Uveodermatologic syndrome in a rat terrier. J Am Anim Hosp Assoc 47(4):e56-e63
  11. Sigle KJ et al (2006) Unilateral uveitis in a dog with uveodermatologic syndrome. J Am Vet Med Assoc 228(4):543-548
  12. 12.0 12.1 12.2 Medleau L & Hnilica KA (2006) Small Animal Dermatology. 2nd ed. St Louis: Saunders Elsevier. pp:292–293
  13. Pye CC (2009) Uveodermatologic syndrome in an Akita. Can Vet J 50(8):861-864