<unk>  is done upon skin biopsy, with direct immunofluorescence staining, in which, if positive, IgG and complement depositions are found at the dermoepidermal junction. This test can be helpful in distinguishing systemic<unk>  erythematosus (SLE) from cutaneous<unk> , because in SLE the<unk>  will be positive in both involved and uninvolved skin, whereas with cutaneous<unk>  only the involved skin will be positive. The minimum criteria for positivity are: * In sun-exposed skin: presence of a<unk>  of deposits of IgM along the epidermal basement membrane in 50% of the biopsy, intermediate (2+) intensity or more. * In sun-protected skin : presence of interrupted (i.e. less than 50%) deposits of IgM along the epidermal basement membrane, intermediate (2+) intensity or more. The presence of other immunoglobulins (especially IgA) and/or complement proteins (especially C4) increases the specificity of a positive test.
Lupus band test
Complement fixation test
Latex fixation test
Reticulin stain
Direct fluorescent antibody
Heterophile antibody test
Rapid plasma reagin
Mantoux test