Inflammatory linear verrucous epidermal nevus (ILVEN) encompasses a spectrum of inflammatory mosaic disorders

Abstract

Background Inflammatory linear verrucous epidermal nevus (ILVEN) is a rare skin disease characterized by pruritic erythematous scaly plaques distributed along the lines of Blaschko. Two cases of ILVEN with CARD14 mutations and one case with a GJA1 mutation have been previously reported. Objective To elucidate the genetic cause of a cohort of patients diagnosed based on clinical and histopathological evaluation with ILVEN. Methods We recruited patients diagnosed with ILVEN based on clinical and histopathological criteria. Exome sequencing of affected skin with or without blood/saliva was performed and germline and somatic pathogenic variants were identified. Results Five patients were enrolled. All had skin lesions from birth or early childhood. Two patients developed psoriasis vulgaris after the diagnosis of ILVEN. The first had a germline heterozygous CARD14 mutation and a post‐zygotic hotspot mutation in KRT10. The histopathologic evaluation did not show epidermolytic hyperkeratosis. The second had a post‐zygotic hotspot mutation in HRAS. Her ILVEN became itchy once psoriasis developed. One patient was re‐diagnosed with linear porokeratosis based on a germline mutation in PMVK and a post‐zygotic second‐hit mutation. Two patients were re‐diagnosed with congenital hemidysplasia with ichthyosiform nevus and limb defect nevus based on germline NSDHL mutations. Conclusion ILVEN is a clinical descriptor for a heterogenous group of mosaic inflammatory disorders. Genetic analysis has the potential to more precisely categorize ILVEN and permits pathogenesis‐directed therapies in some cases.

Hyperkeratotic Pigmented Plaques with Blaschkoid Distribution in a Child: Answer

“…5 Approximately 10% of patients show genetic mosaicism for CARD14. 6 Lichen striatus, also referred to as blaschkoid dermatitis, presents as a thin, arc-shaped line of flat-topped, fleshcolored to pinkish papules or plaques along the upper and lower extremities. 7 The precise cause remains uncertain, and the condition typically resolves on its own.…”

Linear Alopecia in a Healthy Young Woman: Answer

“…Histopathology in the postpubertal stage reveals epidermal hyperplasia, hyperplastic sebaceous glands, and dilated ectopic apocrine glands. 6,7 Secondary skin and appendageal tumors arise in .50% of patients with nevus sebaceus. 8 Although most of these tumors are benign, clinical monitoring is essential and systemic workup may be required.…”

Visual clues for the histopathological diagnosis of psoriasis

“…22 In some patients difficult to get a final diagnosis, genetic analysis has the potential significance for diagnosis and treatment. 23…”

“…22 In some patients difficult to get a final diagnosis, genetic analysis has the potential significance for diagnosis and treatment. 23 In summary, the ñ sign could be a useful visual clue for dermatologists, pathologists, and clinicians with less experience to distinguish between psoriasis and other inflammatory skin disorders. The combination of the ñ sign and neutrophilic infiltration or pustules within the upper epidermis has better sensitivity and specificity for psoriasis, especially when PRP needs to be excluded.…”