Plaque and postauricular nodular mucinosis associated with lupus erythematosus
Authors: Lee Won Soo , Chung Joon , Ahn Sung Ku 
Published: August 2010

A 31‐year‐old Korean man first noticed a large plaque‐like skin lesion with a cutaneous induration on his back in the middle of June 1994, and visited the Department of Dermatology at Yonsei University on August 18,1994. He had been healthy with no specific illness until the development of the skin lesions. Physical examination showed a weli‐developed, moderately nourished man who had a large plaque‐like skin lesion with a hard cutaneous induration about 5–10 cm in diameter on his mid‐back and several scattered nodular lesions on the upper back. He complained of arthralgia and general weakness. Laboratory investigations disclosed the following results: hemoglobin (Hb), 11.3 g/dL; heinatocrit (Hct), 35.3%; antinuclear antibody (ANA) (1:20 cytoplasmic pattern positive). White blood cell (WBC), Aspartic aminotransferase (SGOT), Alanine aminotransferase (SGPT), blood urea nitrogen (BUN), Creatinine, anti‐smooth muscle (anti‐SM), n‐ribonucleo‐protein (n‐RNP), Veneral Disease Research Laboratory (VDRL), Rheumatoid arthritis factor (RA), and urinalysis were negative or within the normal range. A biopsy of a plaque on the upper back showed that the collagen was loosened and replaced by homogeneous mucinous materials containing scattered spindle‐shaped fibroblasts in the upper and mid‐dermis. The mucinous material stained blue with Alcian blue at pH 2.5, but not at pH 1.0, and was periodic acid‐Schiff negative. Direct immunofluorescence showed granular and continuous IgG, C3, and fibrinogen deposits along the dermo‐epidermal junction. According to these findings, a diagnosis of plaque‐like mucinosis was made. The administration of systemic steroid was started at the patient's first visit. During the treatment the previous skin lesions improved, but in March 1995 new skin lesions developed on both postauricular areas. On examination, two slightly erythematous nodules, 10–15 mm in diameter, were seen on both postauricular areas. The patient complained of general weakness, arthralgia, photosensitivity, and transitory facial swelling and erythema. Laboratory tests showed the following results; Hb, 12.2 g/dL; Hct, 38.1%; triglyceride, 253 mg/dL; ANA (1;160 speckled pattern positive); urine protein, 150 mg/dL; urine RBC, 5–9/HPF; urine WBC, 10–29/HPF/ BUN, 22 mg/dL; Creatinine, 1.3 mg/dL. WBC, SGOT, SGPT, chest X‐ray, and ds‐DNA were normal. Light microscopic examination of a nodule showed marked mucin deposition throughout the entire dermis. A sparse perivascular lymphocyte infiltrate was noted. Direct immunofluorescence of a nodule on the postauricular area showed granular and continuous IgG, C3, and fibrinogen deposition along the dermo‐epidermal junction. A lupus band test in uninvolved skin was not carried out at the patient's request. Under a diagnosis of nodular mucinosis associated with systemic lupus erythematosus (SLE), systemic corticosteroid was given for 3 months; subsequently the plaque and nodular skin lesions almost disappeared and the patient's general condition improved. Regular urinalysis showed continued proteinurea despite the treatment, so the patient was referred to the Department of Nephrology for the evaluation of lupus erythematosus (LE) nephritis, which was confirmed after a renal biopsy.