Successful treatment of a novel generalized variant of canine discoid lupus erythematosus with oral hydroxychloroquine

Abstract

Discoid lupus erythematosus (DLE) is a common canine autoimmune disease that usually manifests as a localized ulcerative and scarring nasal dermatitis. We report herein a generalized variant of canine DLE successfully treated with the antimalarial immunomodulator hydroxychloroquine (HCQ). A 9-year-old hairless Chinese crested dog was presented with annular and polycyclic hyperpigmented and scaly skin lesions with central erosions, hypopigmentation and/or scarring on the trunk, neck and lateral extremities. Associated systemic signs were not seen. The clinical diagnosis of generalized DLE was supported by the demonstration of lymphocyte-rich interface dermatitis with epidermal atrophy and dermo-epidermal deposition of immunoglobulins and activated complement. As for human DLE, treatment was initiated with HCQ at 5 mg/kg once daily along with 2 weeks of 0.1% tacrolimus ointment and restriction of sun exposure. Over the following year, complete remission was maintained with HCQ at 5 mg/kg orally once daily with the exception of three relapses; two occurred during treatment induction and the third arose when the frequency of HCQ administration was reduced to every other day. Disease flares were controlled with 0.1% tacrolimus ointment alternating with 0.1% prednicarbate cream once daily for 5-10 days. Altogether, adverse drug events were not seen with this regimen. In summary, clinically, histologically and immunologically, this dog's disease mirrored the generalized discoid variant of chronic cutaneous lupus erythematosus of humans. The apparent benefit of HCQ, its safety and low cost warrant future investigations of its use for treatment of canine cutaneous lupus variants.

Systemic Lupus Erythematosus Discoid in dog (Canis familiaris): case report

“…The subtype of the LEC with the most common clinical presentation is called Systemic Lupus Erythematosus Discoid (SLED) that can be generalized or localized. In dogs, cutaneous lesions are similar to those of the human form [4][5][6]. The disease is manifest with greater frequency in breeds Collie, Pastor of Shetland, German Shepherd and Siberian Husky [3,6,7,8,9].…”

“…This first histopathological examination was not specific, leading to an initial and inconclusive diagnosis of dermatitis, which led to an inadequate treatment for the disease, resulting in the development of clinical signs [3,5,11].…”

“…Specific tests such as monoclonal antinuclear (AAN) and histopathological tests are needed for definitive diagnosis of the disease. The test AAN is positive in 5% of cases, and may indicate seroconversion for LES [3,5].…”

“…The disease can worsen with heavy exposure to sunlight and increase in warm seasons of the year [9]. The diagnosis of the SLED is based on the exclusion of systemic signs of SLE, in addition to nonspecific tests such as complete blood count, biochemical profile, urinalysis, smear [3][4][5]11]. Specific tests such as monoclonal antinuclear (AAN) and histopathological tests are needed for definitive diagnosis of the disease.…”

“…It prevents collect of injuries traumatised with crusts and in the healing process [3][4][5]11]. The therapy to control the disease, aims to reduce clinical signs, using therapies that minimize adverse effects.…”