Canine_discoid_lupus_erythematosus
Discoid lupus erythematosus (DLE) is an uncommon autoimmune disease of the basal cell layer of the skin. It occurs in humans[1] and cats, more frequently occurring in dogs. It was first described in dogs by Griffin and colleagues in 1979.[2][3] DLE is one form of cutaneous lupus erythematosus (CLE). DLE occurs in dogs in two forms: a classical facial predominant form or generalized with other areas of the body affected. Other non-discoid variants of CLE include vesicular CLE, exfoliative CLE and mucocutaneous CLE.[4] It does not progress to systemic lupus erythematosus (SLE) in dogs. SLE can also have skin symptoms, but it appears that the two are either separate diseases.[5] DLE in dogs differs from SLE in humans in that plasma cells predominate histologically instead of T lymphocytes.[6] Because worsening of symptoms occurs with increased ultraviolet light exposure, sun exposure most likely plays a role in DLE, although certain breeds (see below) are predisposed.[7] After pemphigus foliaceus, DLE is the second most common autoimmune skin disease in dogs.[8]