In this regard, IgM pemphigoid seems to differ from classical bullous pemphigoid, although in latter disease about 20% of patients present with non‐bullous variants resembling chronic prurigo, eczema, intertrigo, ecthyma gangrenosum, erythroderma, and toxic epidermal necrolysis.44 This evidence concerns the gene CD40LG and exfoliative dermatitis.