Inflammatory linear verrucous epidermal nevus (ILVEN) and psoriasis in a child?

A male infant, whose father was affected by psoriasis, was first seen in our department at 1 month of life for a "bipolar" seborrheic dermatitis, that resolved without treatment at 7 months of age. At 15 months of life, the child returned for an eruption of erythematous and finely scaling papules disposed in a linear, band-like fashion over the left part of the body, involving the volar surface of the arm, the left leg from the inguinal fold to the ankle, and the abdomen and thorax, where they assumed the typical S-shaped curve following Blaschko lines. The lesions were not itchy. A punch biopsy of a linear lesion on the left arm was performed. Histopathologic examination showed parakeratosis with absence of the granular layer, mild acanthosis with papillomatosis, necrosis of single keratinocytes, and a mild lymphohistiocytic infiltrate located in the superficial dermis. A tentative diagnosis of lichen striatus was made. After a few days, a diffuse eruption of pinpoint-sized, lenticular, erythemato-desquamative lesions occurred on the trunk and limbs, with the typical clinical appearance of guttate psoriasis (Fig. 1). The child was in good general condition, and routine blood tests were within the normal range. No triggering factor was found. Treatment with emollients led to the resolution of the psoriatic lesions within 4 months; in contrast, the linear lesions were not grossly changed by this treatment and just appeared more flattened. The child was seen again at 3 years of age: the linear papular lesions on the left side of the body were unchanged, and stilt asymptomatic. The previous diagnosis of lichen striatus was then changed to linear psoriasis. The clinical picture remained unchanged until the age of 10 years, when the child presented with eruptive, small patches of psoriasis on the trunk and abdomen. Concomitant with this eruption, the child experienced a sudden change in the clinical aspect of the linear lesions, that became more inflammatory, assuming a verrucous and, in some cases, crusting aspect; intense itching developed. Two punch biopsies of a linear lesion on the left leg were performed. The lesion specimen showed orthohyperkeratosis, with the presence of the granular layer, and mild dilation of the vessels of the superficial plexus, with edema and a discrete mononuclear infiltrate. The second specimen showed mild hyperkeratosis with neutrophil microabscesses in the stratum corneum; in a single portion of the specimen, a mononuclear infiltrate in the mid-dermis with edema, exoserosis, and exocytosis was found. Based on the clinical course and on the histopathologic aspect, we made a diagnosis of inflammatory linear verrucous epidermal nevus (ILVEN) with concurrent psoriasis. Treatment with calcipotriol ointment every day for 2 months cleared the nonlinear psoriatic lesions. The linear lesions partially improved (Fig. 2), but did not clear (Fig. 3). Further treatment with clobetasol propionate every day for 1 month improved the itching, but left the linear lesions unchanged.