ABSTRACT
A 10-year-old boy presented with a 3-year history of erythematous flat keratotic papules and brown-yellow, nail-like prominent keratotic plaques all over the body surface. Dermatological examination showed verrucous or nail-like prominence over multiple erythematous keratotic plaques on the head, face,trunk and limbs. The lesions, most of which confluenced, were covered with brown-yellow and greasy crusts,and gave a porcupine-like appearance. Skin biopsy of lesions from the back revealed epidermal hyperkeratosis,focal columnar parakeratosis, acanthosis, few acantholytic and dyskeratotic cells in stratum corneum, irregular upward proliferation of dermal papilla cells, and a superficial perivascular lymphocytic infiltration. A diagnosis of ichthyosis hystrix was established based on the histopathological findings. The boy was treated with oral acitretin and topical 0.1% acitretin cream for 8 years. The initial and maximum dose of oral acitretin was 0.5 mg·kg-1·d-1 and 1 mg·kg-1·d-1, respectively. Liver and kidney function, body height and weight were examined during the treatment, and no side effect was observed except for skin xerosis.