Abstract
Here, we present a 33-years-old pregnant female who at 27-weeks gestation developed an unusual rash on her left knee after a spider bite. The rash rapidly became systemic requiring admission and treatment with high-dose steroids. Patient rapidly developed complications of steroid therapy and saw no benefits in reducing the activity of the rash of symptoms of itching. A repeat biopsy showed linear fluorescence along the dermal epidermal junction with C3 (strong) and IgG (weak) suggestive of pemphigus gestationis (PG). After balancing concerns for the health of the mother and risk for disease transmission to the child, we decided to treat the patient with high-dose intravenous immunoglobulin (IVIg). This resulted in rapid remission of disease and delivery of a healthy child without evidence of PG at 36-weeks gestation. A discussion of the mechanism(s) of action of IVIg that were salutary in this case is presented. Importantly, we discuss the likely benefits of IVIg in saturation of the Fc-receptor neonatal IgG recycling and preservation system in accelerating the degradation of pathogenic IgGs and the inhibitory of effects of IVIg on C3 activation which was the predominant immunoreactant in skin biopsy. The patient recovered completely after the fourth monthly IVIg infusion and continues to do well.