Circumscribed palmar or plantar hypokeratosis: Report of a Korean case and published work review

Circumscribed palmar or plantar hypokeratosis is a rare dermatosis characterized by a solitary, well-circumscribed patch with scaly borders chiefly on the palm or sole; it usually occurs in middle-aged or elderly women. We report the case of a 52-year-old Korean woman with two characteristic lesions of circumscribed palmar hypokeratosis on the left palm. Clinically, the lesions simulated porokeratosis of Mibelli, but histologically there was no cornoid lamellation in the serial sections and there were the characteristic histopathological features of circumscribed palmar or plantar hypokeratosis including a stair-like configuration with an abrupt thinning of the stratum corneum and a decreased granular layer. We also review the 16 cases of circumscribed palmar or plantar hypokeratosis reported in the published work.