Symmetrical lupoid onychodystrophy in dogs: a retrospective analysis of 18 cases (1989-1993)

Abstract

A unique, symmetrical onychodystrophy is described in 18 dogs. A rather sudden onset of onychomadesis is followed by chronic onychodystrophy affecting all claws. Pain and lameness are recognized in half of the patients, but the dogs are healthy otherwise. Histopathologically, this disorder is characterized by hydropic and lichenoid interface dermatitis. Nine dogs were treated with a commercial, fatty-acid supplement and had good-to-excellent responses. Due to the clinicopathological characteristics of this disorder, the authors propose the name "symmetrical lupoid onychodystrophy."

Immunohistochemical Evaluation of Mononuclear Infiltrates in Canine Lupoid Onychodystrophy

“…However, in a subsequent prospective study of this syndrome, 25 no other systemic or cutaneous features of canine lupus erythematosus could be identified. Furthermore, in that study, dogs with claw disease due to pyoderma and food adverse reaction showed the same histopathologic features described by Scott et al 34 These features included interface dermatitis, lymphocytic exocytosis, and hydropic degeneration of the basal cell layer, and the authors suggested that the observed interface dermatitis may be a reaction pattern of the canine claw matrix rather than being diagnostic for a particular etiology. As T and B lymphocytes cannot be differentiated readily on sections stained with HE and as activated lymphocytes and histiocytes may have a similar appearance, we attempted to further characterize the mononuclear infiltrate seen in canine lupoid onychodystrophy using a panel of monoclonal antibodies.…”

“…3,5,15,[25][26][27]33,34,36 These studies attempted to define claw disease and possible etiologies in more detail and gave useful information. One of these studies reported a number of dogs with exclusive claw disease, where the only histopathologic findings documented were a bandlike mononuclear infiltrate with interface dermatitis changes, 34 including basal cell hydropic degeneration, degeneration or necrosis of individual keratinocytes in the basal cell layer, and pigmentary incontinence. Interface dermatitis and a bandlike infiltrate of plasma cells and lymphocytes have been reported as suggestive of discoid (cutaneous) or systemic lupus erythematosus in the dog.…”

“…13,34,39 The proposed name for this claw syndrome was lupoid onychodystrophy. 34 No other signs of systemic lupus erythematosus, such as elevated antinuclear antibody titers, anemia, thrombocytopenia, or evidence of glomerulonephritis based on urinalysis and biochemistry panels, were present in dogs with lupoid onychodystrophy in a subsequent prospective study. 25 Furthermore, some dogs with these histopathologic features were diagnosed with bacterial infection or food adverse reaction, indicating that the presence of bandlike mononuclear infiltrates and interface dermatitis may be a ''reaction pattern'' of the canine claw.…”

DLA Class II Alleles Are Associated with Risk for Canine Symmetrical Lupoid Onychodystropy (SLO)

“…Typically the inflammatory infiltrate forms a parallel band to the basement membrane called lichenoid pattern. Pigmentary incontinence is also often observed in the dermis [4]. Treatment with immunosuppressive drugs, such as glucocorticoids, has been reported to be successful [5] as well as fatty acid supplementation [6] suggesting an autoimmune aethiology of the disease.…”

A randomized comparative clinical trial of recombinant canine interferon‐γ (KT‐100) in atopic dogs using antihistamine as control

“…In general, serum testing is considered to be no more reliable than intradermal skin testing for the identification of causative allergens in atopic patients 19 and the results of ELISA vary depending on the assay used, the antibody measured and the allergens tested. Mueller et al demonstrated that 27.4% of atopic dogs showed negative serological testing for IgE, compared with the results of intradermal skin testing.…”