1, lupus erythematosus: manifested by banded or granular deposition of basement membrane band IgG, IgM, C3; 2, herpetiform aspergillosis: manifested by banded deposition of basement membrane band IgG, C3, salt cracked skin seen deposited on the epidermal side; 3, aspergillosis: manifested by interspinous cell IgG, IgA, IgM, C3 in a reticular pattern; Guangdong Wen, Department of Dermatology and Venereology, Peking University People’s Hospital 4, certain cutaneous vasculitis: manifested by deposition of IgM, C3 in the skin vascular wall; 5, linear IgA maculopathy, acquired herpetic epidermolysis bullosa, etc. may also manifest as direct immunofluorescence positivity.