Pseudopemphigoid as caused by topical drugs and pemphigus disease

Figure 2 Direct immunofluorescence studies of conjunctival biopsies. A: Conjunctival mucous membrane pemphigoid showing thick linear IgG along the lamina propria in a background of squamous metaplasia; B: Conjunctival pemphigus vulgaris showing linear IgG deposition on desmosomal areas of epithelial cell surfaces displaying a classic “chicken-wire” pattern; C: Conjunctival paraneoplastic pemphigus (PNP) showing linear IgG along the lamina propria with a hemidesmosomal pemphigoid-like in conjunction with a desmosomal pemphigus vulgaris-type epithelial cell surface “chicken-wire” type pattern. The pattern in PNP is due to the presence of IgG autoantibodies against hemidesmosomal antigens (plakin proteins: BP230/BPAG1 and plectin) as well as desmosomal antigens (plakin proteins: desmoplakin, envoplakin, periplakin, and desmogleins 3 and 1); D: Conjunctival pseudopemphigoid (most likely drug-induced) showing negative IgG deposition along the lamina propria in a background of subepithelial clefting, mild submucosal fibrosis, and incipient epithelial metaplasia.