Bilateral Sporotrichoid Cutaneous Infection by Mycobacterium haemophilum in a Chinese Patient with Systemic Lupus Erythematosus

Abstract

We report a case of an immunocompromised 30-year-old woman with systemic lupus erythematosus (SLE) with bilateral sporotrichoid cutaneous infection caused by M. haemophilum. The patient initially presented with painful deep erythematous nodules and ulcerations on her left forearms for several months. These nodular lesions were arranged along the lymphatic path and became suppurative, ulcerative, and crusted. Subsequently, the symmetrical part of the dorsum of the patient’s right hand showed a similar nodular lesion (Fig. 1A–C). Eight years earlier, she was diagnosed with SLE and intermittently treated with steroid therapy (dosage was unknown), however, the facial rash still relapsed. Currently, the patient is receiving 20 mg prednisone once daily. Her medical history revealed no other systemic diseases and she denied any preceding history of trauma, gardening, or dealing with fish tanks. Laboratory examination showed the platelets were 23 × 109/l (normal: 100–300 × 109/l) and the hemoglobin was 105 g/l (normal: 110–150 g/l). Urine routine examination showed proteinuria and occult blood. Immunological findings included positive results for ANA (1:1,000), anti-RNP, and anti-SSA. The purified protein derivative (PPD) test and human immunodeficiency virus (HIV) antibody test were negative. Histological examination of an erythematous nodule on the patient’s left forearm revealed an abscess and granulomas without caseous necrosis in the superficial and mid-dermis, which involved mainly neutrophils, as well as lymphocytes, histiocytes, plasmocytes, and a small amount of eosinophils (Fig. 1D, E). The epidermis was mildly hyperplastic and Ziehl–Neelsen staining of the histopathology lesions revealed acid-fast bacilli (AFB) (Fig. 1F). Other specific stains, such as periodic acid Schiff and Giemsa stains, for microorganisms were negative. Biopsy specimen culture for mycobacteria on a Lowenstein–Jensen medium was negative. Therefore, a direct sequencing protocol targeting hsp 65 and 16S rRNA genes of mycobacterium was applied in the tissue specimen. Sequence analysis of hsp65 genes indicated 100% homology with the M. haemophilum strain ATCC 29548, and 16S rRNA genes showed 99% similarity with M. haemophilum strain DSM 44634. Gene sequences were analysed using BLAST V2.0 software avail able at http://www.ncbi.nlm.nih.gov/BLAST/. The organism, when biopsy specimens were cultured for the second time on a blood Bilateral Sporotrichoid Cutaneous Infection by Mycobacterium haemophilum in a Chinese Patient with Systemic Lupus Erythematosus