Sign of Leser–Trélat: the sudden appearance or increase in number and size of seborrheic keratosis on non-inflamed skin has been reported to be a sign of internal malignancy.

Dermatomyositis: heliotrope erythema of the eyelids (heliotrope: violet) can be paraneoplastic condition. This can be misdiagnosed as eyelid dermatitis.

Sweet syndrome. Acute tender erythematous plaques and pseudovesicles, and occasional blisters.

Paraneoplastic pemphigus. Widespread polymorphous eruption with papules and blisters. There were painful oral ulcerations. Total resection of the neoplasm may cure the disease.