Through immunoprecipitation, target antigens have been found to include desmoglein-3, desmoglein-1, envoplakin, periplakin, desmoplakin 1, desmoplakin 2, and bullous pemphigoid antigen I.The precise mechanism for how tumors are able to induce autoantibodies toward the plakin proteins is unknown. Suggested theories include tumor production of plakin proteins which initiate an autoimmune response against them, and cross-reactivity of tumor antigens and epidermal antigens.Once the molecules that hold the various levels of the membranes together are attacked, they are unable to function properly, and the tissue breaks apart. This is manifested as the associated blistering and lesions of PNP. Diagnosis
In order to diagnose paraneoplastic pemphigus, several tests may be performed. Initially, samples are obtained via skin biopsy for routine microscopy and direct immunofluorescence (DIF) testing. The skin sample needs to be obtained from an unaffected area adjacent to a lesion. Testing in more detail follows depending on the results from the DIF. Prompt diagnosis of PNP is crucial due to the high mortality rate of the disease. Camisa and Helm revised the original criteria from Anhalt et al.
Discrete papular lichen myxedematosus is a skin condition caused by fibroblasts producing abnormally large amounts of mucopolysaccharides characterized by the occurrence of waxy, flesh-colored papules. : 185

See also
Papular mucinosis
List of cutaneous conditions

References


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