Immunoelectronmicroscopic differentiation of linear IgA bullous dermatosis of adults with coexistence of IgA and IgG deposition from bullous pemphigoid.

BACKGROUND

The differentiation between linear IgA bullous dermatosis (LABD) and bullous pemphigoid (BP) is sometimes difficult in patients who have both IgA and IgG deposition in a linear pattern at the basement membrane zone.

OBJECTIVE

We address whether two cases of acquired subepidermal blistering disease with coexistence of IgA and IgG deposition in a linear pattern at the basement membrane zone are LABD or BP.

METHODS

The two cases were investigated by immunoelectron microscopy and compared with two typical cases of LABD.

RESULTS

In both cases, the deposition of IgA and IgG was ultrastructurally localized below the lamina densa in close association with anchoring fibrils, as was seen in two cases of typical LABD.

CONCLUSION

These findings indicate that our two cases of acquired blistering disease with co-existence of IgA and IgG deposition are LABD, rather than BP.