PMC9714672_01
Clinical picture. Discrete swelling and erosions (highlighted by arrows) around the gingival fringes of the upper (A) and lower tooth space (B), as well as a painful ulcer at the urethral entrance were identified at initial presentation (C). Inconspicuous mucosal findings of the upper gingiva (D) and lower gingiva (E) and urethral outlet (F) followed initiation of therapy with prednisolone combined with dapsone.
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F1
Clinical examination showed an ulcer on the urethral outlet area, but also few erosions on the gingiva, which mimicked a mild gingivitis (Figure 1).
Direct immunfluorescence (DIF) of buccal mucosa shows linear IgG and C3 depositions at basement membrane zone, each indicated by arrows (A,B). DIF found no reactivity for IgA (C). Indirect immunofluorescence on 1M split human skin using patient's serum shows epidermal staining of IgG (D). Histopathology of buccal mucosa of the patient (hematoxylin-eosin stain, 200x magnification) (E). Immunoblot analysis revealed IgG autoantibodies against BP230 and slightly also against collagen VII (F).
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F2
IgG reactivity at blister roof, compatible with an active pemphigoid disorder (Figure 2A). In addition, an isolated positive BP230 ELISA at 85 U/ml (cut of > 9 U/ml) was identified, while NC16A BP180 ELISA was negative (MBL, Nagoya, Japan). IgG and C3 deposition at the dermal-epidermal junction in the direct immunofluorescence (Figures 2B-D). Immunoblotting analysis using human epidermal extract as substrate showed IgG immunoreactivity with BP230 and slightly also collagen VII (Figure 2F). IgA autoantibodies did not react in any analysis. Histological examination taken from buccal mucosa yielded a hyperplastic, non-keratinizing, mucosal epithelium without cleavage (Figure 2E).