Chilblain lupus erythematosus associated with systemic lupus erythematosus: A classic diagnosis in a current epidemiological context

ABSTRACT

Objectives: Chilblain lupus erythematosus (LE) is a rare chronic cutaneous lupus erythematosus (CCLE) characterized by the appearance of violaceous plaques in acral regions most exposed to cold. The isolated form affects middle-aged women, while the familial form manifests in early childhood and is associated with mutations in the TREX1 gene. Result(s) A 13-year-old adolescent, with no relevant family history, was referred in March 2021 for suspected chilblain-like lesions associated with COVID-19 infection. The patient presented with multiple violaceous papules on hands and feet. The lesions were slightly painful. Small hyperkeratotic papules were also observed on finger pads. Physical examination also revealed some aphthae affecting the lips. No other systemic symptoms were reported. A skin biopsy and blood tests were performed due to presumed chilblain LE with probable systemic involvement. Histology revealed basal vacuolar damage and intense perivascular and periadnexal lymphocytic inflammatory dermal infiltrate. Remarkably, mucin was noted among the collagen bundles. Leukopenia and positive ANA antibodies (titre 1320) were detected. Complement levels were normal. SARS-CoV2 infection was ruled out. Skin lesions disappeared within 1 month under topical corticosteroids. Hydroxychloroquine was afterwards started by Rheumatology without recurrence of skin symptoms until last follow-up. Discussion(s) We present an uncommon case of an adolescent with systemic LE presenting as chilblain LE. Chilblain LE can be accompanied by other discoid CCLE. It can progress to systemic LE in up to 20% of patients, especially when concomitant CCLE is present. This rare presentation of CCLE should be differentiated from typical chilblain and other resembling lesions, such as SARS-CoV2-associated chilblain and acral purpuric lesions (COVID toes). The Mayo Clinic diagnostic criteria can be helpful, particularly in this last SARS-CoV2 outbreak scenario, when the reporting of similar skin lesions has been significant.