A case of disseminated superficial porokeratosis with inflammatory stage

A 79-year-old female who had suffered from asymptomatic, annular, hyperkeratotic, brownish macules on the extremities and trunk for 7 years spontaneously developed pruritic erythematous changes of the pre-existing lesions as well as newly formed erythematous papules. A histopathological examination showed typical cornoid lamella and a perivascular infiltration of lymphocytes and eosinophils in the upper dermis. Laboratory investigations revealed eosinophilia. After an inflammatory period lasting for 16 months, the pruritic erythematous changes and the eosinophilia gradually improved, leaving annular, brownish, mildly hyperkeratotic macules. Our case was unusual for its transient inflammatory condition of disseminated superficial porokeratosis (DSP), which was consistent with the previously reported "Inflammatory stage of DSP".