Abstract: A 11-year-old female is hereby reported, who presented with subungual hyperkeratosis, yellow scab on the corner of the mouth, oral leukokeratosis and numerous hyperkeratosis lesions all over the body. Histological examination showed hyperkeratosis and parakeratosis of epidermis, acanthosis, dilation and hyperemia of dermal papilla vessels, and histiocytic infiltration surrounding vessels. The features were consistent with a diagnosis of pachyonychia congenita type 1. Her father has a similar history.