A 47-year-old woman presented with a pustular rash (Figure and ) on her skin (face, back, forearms and leg) and pustular inguinal eruptions; on one occasion she had developed a vulvar infection with abscess formation requiring drainage. Past medical history included recurrent rhinosinusitis and anxiety disorder. Biopsy of the lesion showed pustular changes with neutrophilic infiltration, but did not reveal lymphocyte infiltration. A culture from a lesion on her forearm was positive for Staphylococcus aureus. The patient responded to administration of cefadroxil and minocycline, with remission and frequent relapses. Laboratory workup revealed mild C4 deficiency and an undetectable IgE level (Table ). Assays were unremarkable for ANA, ESR, rheumatoid factor, hepatitis viruses, and HIV. The MBL level was exceptionally low at < 50 ng/ml, and her MBL functional pathway was impaired. MBL genotyping revealed a LYPB/HYPD haplotype, while MASP-2 was wild-type (Table ).
49-year-old woman with complaints of a blistering skin eruption and hyperpigmentation for the past 6 years; the lesions were thick, tender, indurated, and presented with yellow-green secretion. Her past medical history included recurrent impetigo, perennial rhinitis, and ulcerative colitis. On exam, a 1-inch area of induration and erythema was observed over her chin (Figure and ); there were multiple scattered pustular lesions over the forearms, some ulcerated. Encrusted pustules were also observed over her scalp, face, back and legs. Work-up yielded a weakly positive ANA and an elevated CRP (10 mg/L) (Table ). MBL levels were low at < 50 ng/ml. Punch biopsy from her forearm (Figure ) revealed histopathology and morphology compatible with Candida sphaerica, although the possibility of Trichophyton rubrum was also raised; cultures were attempted from a specimen but no growth was observed. An aspirate of one of the pustules grew Sphingomonas paucimobilis. Terbinafine and levofloxacin were given, and her eruption resolved. Genotyping revealed LXPA/LYPB for MBL and A/G for MASP-2 (Table ). The MBL functional assay was also impaired.