Causes
Discoid lupus erythematosus
The causes of DLE are both endogenous and exogenous. Endogenous factors involve genetic predisposition, particularly major histocompatibility complex alleles HLA-DQA1 and DRB1, and certain genetic polymorphisms associated with cytokine regulation. Exogenous factors include smoking and ultraviolet radiation, which can exacerbate DLE due to its photosensitive nature.
DLE may present as localized (affecting above the neck in 80% of cases) or generalized (affecting both above and below the neck in 20% of cases). While the rash is typically asymptomatic, it can cause itching and soreness. Most patients with DLE only experience skin involvement, but some may develop signs of systemic lupus erythematosus (SLE).
