LAUSR

Figure 1. A) Linearly distributed keratotic and pitted papules, coalescing into plaques, over the left upper limb. B, C) Histopathology showing hyperkeratosis, acanthosis, and parakeratotic invaginations into the epidermis with focal hypogranulosis; acrosyringeal ducts in the upper dermis underly the cornoid lamellae (H&E, x40 in [B] and x100 in [C]). bump over the hand and gradually progressed over the next two years to its present size and extent. The condition was stable henceforth. Clinical examination revealed multiple skin-coloured to brownish discrete keratotic and pitted papules, coalescing into plaques, arranged linearly over the lateral border of the left upper limb, involving the dorsum of the hand and forearm up to the mid-arm (figure 1A). Skin biopsy from a representative lesion, followed by histopathological examination, showed hyperkeratosis, acanthosis, and parakeratotic invaginations in the epidermis with focal hypogranulosis; acrosyringeal ducts in the upper dermis were shown to underly the cornoid lamellae (figure 1B, C).