UVB-induced acantholysis in endemic Pemphigus foliaceus (Fogo selvagem) and Pemphigus vulgaris.

BACKGROUND

The autoantibody-mediated disease in fogo selvagem (FS) is aggravated by sunlight exposure.

OBJECTIVE

The aim of this study was to test whether UVB exposure of uninvolved skin of patients with FS (n = 21) enhances epidermal acantholysis and in vivo binding of FS autoantibodies as compared with a control group (n = 4). Another control group included 8 patients with pemphigus vulgaris (PV).

RESULTS

Exposure of uninvolved skin of FS to UVB induces acantholysis (15/21 patients) with in vivo binding of IgG and C3 to the epidermal intercellular spaces (17/21 patients). Similar results were found in PV (6/8 patients). The test was negative in the control group.

CONCLUSION

Sunlight exposure is harmful in the clinical course of patients with FS and those with PV. Protection from sunlight should be part of the treatment of these patients.