Calcinosis cutis causing cutaneous ulceration and secondary bacterial infection in a patient with antinuclear matrix protein 2 antibody-positive dermatomyositis.

Abstract

An 84-year-old woman visited our hospital because of swelling and severe pain in the right middle finger. Eighteen years earlier, skin rashes and subcutaneous calcification on the fingers appeared; she was later diagnosed with antinuclear matrix protein 2 (NXP2) antibody–positive dermatomyositis. Two weeks prior to presentation, new subcutaneous calcified lesions were noted on the right middle finger, with one lesion developing an ulceration. Three days before presentation, the patient had swelling and severe pain in her right middle finger, which gradually spread to her right forearm. On examination, redness, swelling, and tenderness were noted in the finger (Fig. 1A). The finger had calcified lesions, one of which had pus coming out (Fig. 1B,C). The redness spread in a linear pattern (Fig. 1D). Laboratory testing revealed elevated inflammatory markers. The patient was diagnosed with ulcerated calcinosis cutis and secondary bacterial infection (acute cellulitis with subcutaneous abscess and lymphangitis). Because of the severe pain and the increasing extent of lymphangitis, we decided to perform early drainage of the abscess for source control. Therefore, intravenous antibiotics were started immediately after diagnosis, and the patient was in the operating room 2 h later. During operation, subcutaneous abscess formation was observed in the middle finger; thus, debridement of the lesion was performed. Microscopic examination showed pus mixed with countless neutrophils and microcalcifications (Fig. 1E). Postoperatively, the inflammation improved after treatment with antibiotics for 2 weeks. Calcinosis cutis is an uncommon complication of dermatomyositis,1 including anti-NXP2–positive dermatomyositis,2 and its complications are rarely reported. However, calcinosis cutis had led to skin ulcerations and secondary bacterial infections in very few cases.3 As observed in the present case, ulcerative calcinosis cutis can lead to cellulitis complicated by subcutaneous abscess and progressively enlarging lymphangitis, which may require emergency debridement. None. No funding information provided. Approval of the Research Protocol with Approval No. and Committee Name: N/A. Informed Consent: Written informed consent was obtained from the patient. Registry and the Registration No. of the Study/Trial: N/A. Animal Studies: N/A. Conflict of Interest: None declared.