A 61-year-old man presented with recurrent folliculitis-like eruptions of the skin. His history was significant for a prior history of infection of the cheek with methicillin-resistant Staphylococcus aureus (MRSA) treated with minocycline. Six years earlier, he had suffered infection of a pacemaker site with MRSA, which had spread to his upper extremities, but was ultimately controlled with antibiotics. He denied intravenous drug use. Physical examination revealed a 1-cm indurated nodule over his left cheek, a 5 × 3 cm hyperpigmented patch over his left ankle, and scattered areas of erythema over his anterior chest wall and dorsum of his legs. MBL level was < 50 ng/ml, while all classes of immunoglobulins were within normal range (Table ). MBL genotyping revealed the LYPB/HYPD haplotypes. MASP-2 genotype was the wild type (A/A). MBL functional pathway test was impaired (Table ). A skin biopsy of the folliculitis-like rash (Figure ) was performed, revealing Grover's disease (transient acantholytic dermatosis). Topical therapy was instituted with triamcinolone.
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 ).