Chilblain lupus erythematosus (chilblain LE) is a subtype of chronic cutaneous lupus erythematosus (CCLE). Others in this group include discoid lupus erythematosus (DLE), lupus erythematosus tumidus (LE tumidus), and lupus profundus (lupus panniculitis).

Chilblain LE is characterized by circumscribed, dusky red papules and plaques on the dorsal and lateral aspects of the hands and feet, including the fingers and toes. Involvement of the heels, nose, and ears may also occur. The lesions may be itchy, painful, or asymptomatic and are precipitated by exposure to cold, damp conditions. Photosensitivity is not observed.

Most patients with chilblain LE have immunologic abnormalities, including polyclonal hypergammaglobulinemia, elevated rheumatoid factor, and/or antinuclear antibodies, in particular anti-Ro/SSA.

Chilblain LE may be sporadic or familial. Sporadic chilblain LE most commonly occurs in middle-aged women. This variant has been reported in association with anorexia, intestinal lymphoma, and pregnancy. An estimated 20% of cases of sporadic chilblain LE progress to systemic LE. The pathogenesis of sporadic chilblain LE has been related to vasoconstriction or microvascular injury secondary to cold exposure, as well as hyperviscosity and stasis secondary to immunologic abnormalities. A rarer form of familial chilblain LE may manifest within the first years of life. This form of the disease is associated with autosomal dominant, heterozygous mutations of the TREX1 gene, which encodes a 3-prime repair DNA exonuclease with high specificity for single-stranded DNA. The sporadic and familial forms of chilblain LE are clinically and histologically indistinguishable, despite their differing pathogenetic mechanisms.