Clinical and microscopic features of generalized discoid lupus erythematosus in dogs (10 cases)

Abstract

Background -Generalized discoid lupus erythematosus (GDLE) is a newly recognized canine variant of chronic cutaneous lupus erythematosus (CLE) that is not well characterized.Hypothesis/Objectives -We report herein the signalment, clinical signs, treatment outcome, histopathology and immunological findings of 10 dogs with GDLE.Methods -Inclusion criteria were: (i) a >3 month history of generalized skin lesions indicating a chronic or recurrent nature; (ii) skin lesions resembling those of human GDLE; (iii) histopathology of CLE (lymphocyte-rich interface dermatitis). Direct immunofluorescence (IF) and antinuclear antibody serology were investigated whenever possible.Results -Various breeds were affected in their mid-to late adulthood. Selection criteria of generalized multifocal, annular ("discoid") to polycyclic plaques with pigment changes, erythematous margin, adherent scaling, follicular plugging and central alopecia were shown in all dogs. In nine dogs, plaques contained mild to moderate central scarring with depigmentation and/or hyperpigmentation. There were no dogs in which the disease progressed to systemic lupus erythematosus within a median follow-up of 2.5 years. Per inclusion criteria, interface dermatitis occurred with basement membrane zone (BMZ) thickening, suprabasal apoptosis and/or dermal fibrosis in some dogs. Infundibular interface folliculitis was common; it sometimes transitioned to mural folliculitis in lower follicle segments, and occurred with follicular and sebaceous gland atrophy. The direct IF revealed patchy deposition of immunoglobulin IgG and IgM at the BMZ. Lesions responded to a variety of treatments, including ciclosporin, hydroxychloroquine, topical tacrolimus and tetracycline/niacinamide. Relapses were common after medications were tapered.Conclusions and clinical importance -These observations support the existence of a canine homologue of human GDLE.

Treatment of exfoliative cutaneous lupus erythematosus in a German shorthaired pointer dog with mycophenolate mofetil

“…Furthermore, the dog exhibited irregular and polycyclic patches and plaques with hyperpigmentation, erythema and adherent scaling on ventral abdomen and limbs. Such patch/plaque skin lesions also have been reported in dogs with other forms of CCLE, for example in those affected with generalized DLE (GDLE) . However, the erosions and prominent scarring observed in canine GDLE, were not a clinical feature in the current case.…”

“…Such patch/plaque skin lesions also have been reported in dogs with other forms of CCLE, for example in those affected with generalized DLE (GDLE) . However, the erosions and prominent scarring observed in canine GDLE, were not a clinical feature in the current case. Our case, like many GSHPs with ECLE, showed signs of stiff gait, lameness and arched back, suggestive of arthralgia.…”

Therapeutic effectiveness of calcineurin inhibitors in canine vesicular cutaneous lupus erythematosus

“…This small retrospective case series suggests that oral or topical CIs represent an effective therapeutic option with minimal long‐term adverse effects for dogs with VCLE. Because they are potent T‐cell inhibitors, ciclosporin and tacrolimus have been used successfully for treatment of several canine CLE variants, such as exfoliative CLE (ECLE), mucocutaneous lupus erythematosus (MCLE), and localized and generalized discoid lupus erythematous (DLE) . The dosage of ciclosporin used in the present study (5.0–10.0 mg/kg) mirrored those administered in dogs with generalized DLE and ECLE .…”

“…Because they are potent T‐cell inhibitors, ciclosporin and tacrolimus have been used successfully for treatment of several canine CLE variants, such as exfoliative CLE (ECLE), mucocutaneous lupus erythematosus (MCLE), and localized and generalized discoid lupus erythematous (DLE) . The dosage of ciclosporin used in the present study (5.0–10.0 mg/kg) mirrored those administered in dogs with generalized DLE and ECLE . Interestingly, in several dogs with partial improvement or recurrence of VCLE upon CI dose tapering, an increase in the dosage of ciclosporin (up to 10.0 mg⁄kg) or the addition of ketoconazole, which leads to increased ciclosporin concentrations, resulted in CR and long‐term control of skin lesions.…”

“…Hydroxychloroquine has also been shown to inhibit the development of CLE‐like skin lesions in MRL/ lpr mice by reducing the number of mast cells in the dermis and by suppressing the expression of IL‐2 . Oral HCQ has been safely used in canine ECLE and GDLE, at dosages of 5–10 mg/kg/day with some evidence of clinical efficacy . The reported blood HCQ concentrations in two dogs that had a partial improvement of lesions of ECLE were within the recommended therapeutic range for human CLE (range 500–1,000 ng/mL; Dog 1: 560 ng/mL; Dog 2: 870 ng/mL), although these did not reach the level of 900 ng/mL that is associated with human CLE remission .…”