A 2½-year-old male child presented with generalized scaly eruption since three months of age, which were progressively increasing. These were linear as well as circumscribed dark brown to dirty looking hyperkeratotic and verrucous plaque lesions distributed bilaterally and symmetrically, over the neck, trunk and extremities (Fig. 1). Some of the individual papular lesions were spiny. The linear arrangement of lesions was conspicuous over the limbs especially over the dorsa of hands. The scalp, face, palms and soles were spared but genitalia was involved. The hair and nails were normal. Skin biopsy showed features of epidermolytic hyperkeratosis. On the basis of these findings, a diagnosis of ichthyosis hystrix was made.

Fig. 1. Bilateral, symmetrical linear arrangement of dark brown to dirty looking hyperkeratotic and verrucous plaque lesions, along the lower extremities.

 Ichthyosis hystrix is a rare form of linear epidermal nevus. Verrucous epidermal nevi may be localized or diffuse. An epidermal nevus with diffuse or extensive distribution is called a systematized epidermal nevus. When the lesions are distributed on one half of the body, it is termed nevus unius lateris, whereas, an epidermal nevus with extensive bilateral distribution is referred to as ichthyosis hystrix. The abnormality consists of multiple verrucous pink papules that may also be dirty gray or brown, arranged in a linear pattern. Systemic retinoids have shown to produce limited and temporary response in this condition. Generally, these epidermal nevi grow for a variable period of time and then become quiescent.

Devinder Mohan Thappa,
B. Jeevankumar,
Department of Dermatology and STD,
Jawaharlal Institute of Postgraduate Medical
Education and Research (JIPMER),
Pondicherry 605 006, India.
E-mail: [email protected]