LAUSR

A 41‐year‐old woman was admitted to our clinic with new onset SLE. There was no history of psoriasis in the patient or her immediate family. She was prescribed HCQ (200 mg twice daily) and prednisone (30 mg once daily). After 2 months of treatment, the patient presented with diffuse erythema and scaling involving the entire body, HCQ was withdrawn, and prednisone was increased to 60 mg once daily. Physical examination showed erythroderma involving approximately 100% of her body surface area with a Psoriasis Area and Severity Index score of 61.2 [Figure 1a and 1b]. The toenails were yellow and showed hyperkeratosis with thickened nail plates [Figure 1c]. Laboratory findings showed leukocytosis (white blood cell [WBC] count 19.97 × 109/L with 16.42 × 109/L neutrophil granulocytes), hemoglobin 12.4 g/dl, platelet count 525 × 109/L, alanine aminotransferase 43 U/L, aspartate aminotransferase 21 U/L, hs‐CRP 52.05 mg/L, ESR 36 mm/h, and PCT 0.5 ng/ml. Antinuclear antibody (+1:320), anti‐Rib, and anti‐histone antibodies were positive. Alopecia, decreased WBC (3.3 × 109/L), C3 (0.896 g/L), and C4 (0.093 g/L), and positive urinary protein had appeared over the course of the disease. Histopathologic findings revealed parakeratosis, acanthosis cell layer thickening, irregular elongation of rete ridges, dilated dermal blood vessels, and perivascular lymphomonocytic infiltration in the dermis [Figure 1d]. This patient had no previous history of psoriasis; lesions appeared after HCQ was given and receded when HCQ withdrawn. Punch biopsy showed psoriasis‐form dermatitis, and a diagnosis of erythrodermic psoriasis was established. The patient was started on tripterygium glycoside (20 mg three times daily) and showed improvement of skin lesions within 2 weeks.