Idiopathic acquired true leukonychia: a unique entity.

Idiopathic acquired true leukonychia is a rare benign acquired disorder that typically affects adults. Diagnosis is made clinically, with investigations required to exclude any underlying cause. The cause of this condition is largely unknown, yet it understandably causes significant anxiety to patients due to concerns about underlying systemic disease. We report a case of idiopathic acquired true leukonychia totalis in a healthy 20-year-old man. Intermittent complete whitening of some of the fingernails was reported over a 7-year period. No underlying medical cause or laboratory abnormality was identified. This case highlights the importance of considering idiopathic acquired true leukonychia as a differential diagnosis of nail whitening. In addition, increased awareness of this unique entity is needed for patient reassurance, as well as avoidance of unnecessary investigations and prolonged systemic treatment.

[Translated article] Congenital and Hereditary Nail Disease.

Nail disorders in newborns can show independently or as components of systemic illnesses or genodermatoses. The examination of these abnormalities is complex and sometimes challenging. However, familiarity with these disorders can significantly contribute to uncovering potential underlying conditions. This review includes the physiological nail changes seen within the first few months of life, such as Beau's lines, onychoschizia, koilonychia, congenital nail fold hypertrophy of the first digit, and onychocryptosis. This review also focuses on the most relevant congenital disorders reported and how to perform differential diagnosis. Finally, this review highlights those hereditary diseases in which nail involvement is crucial for diagnosis, such as nail-patella syndrome, congenital pachyonychia, or congenital dyskeratosis, among others.

Congenital nail abnormalities.

Congenital nail disorders are an uncommon presenting symptom which can be difficult to diagnose and manage. Nail diseases in the pediatric population differ from those in adults in terms of diagnosis, approach and management. In most cases, they do not require treatment and resolve with growth. Physicians need to be able to recognize them, to reassure the parents. The most frequently encountered pathologies associated with nail disorder are syndactyly, acrosyndactyly, symbrachydactyly, macrodactyly, Wassel I thumb duplication, Kirner's deformity and congenital onychodysplasia of the index finger. Treatment usually consists in surgical correction of the deformity. Nail malformation can also be an aspect of a systemic disease. It may provide a clue for screening, and should not be overlooked. Nail conditions can be the first sign of nail-patella syndrome, ectodermal dysplasia, dyskeratosis congenita, epidermolysis bullosa, pachyonychia congenita or lung disease. Medical treatment is therefore discussed on a case-by-case basis.

Clinical and capillaroscopic findings in patients with liver disease and proximal apparent leukonychia (Terry nails and its variants).

ABSTRACT: Terry nails and Lindsay nails are similar forms of proximal apparent leukonychia (PAL). A change in nail bed vascularity is thought to be responsible for PAL. The study was aimed at investigating the frequency of PAL in patients attending a liver disease clinic, the factors associated with its presence, its value for detecting cirrhosis, its prognostic value for mortality, and associated capillaroscopic findings.A total of 521 patients were included (age range, 18-94 years; 69% men). Systematic nail photographs were evaluated by 2 independent investigators. Disease-related data were obtained from the medical records. Mortality was evaluated after 7 years of follow-up. Nailfold capillaroscopy was performed on a subset of 80 patients.PAL was present in 228 patients (43.8%; Terry nails in 205, Lindsay nails in 20, and both in 3). The kappa-coefficient of interobserver agreement was 0.82. The presence of PAL was associated with cirrhosis and, accordingly, with portal hypertension and hepatocellular dysfunction. The positive likelihood ratio of PAL for the diagnosis of cirrhosis was 1.6 (95% CI 1.3-1.92). PAL was independently associated with chronic alcohol abuse and was not a significant predictor of mortality. Venous loop dilatation and prominence of the venous plexus were observed on capillaroscopy in patients with cirrhosis but were not significantly associated with PAL.In summary, PAL is a common finding in patients from a liver clinic; it is associated with liver cirrhosis and with alcohol abuse. PAL is not associated with specific capillaroscopic findings. We propose the generic term proximal apparent leukonychia instead of classic eponymous titles to avoid confusion in the literature.

Identification of two novel mutations in the PLCD1 gene in Chinese patients with hereditary leukonychia.

Hereditary leukonychia (HL) is a rare nail dystrophy disease, and several different clinical manifestations and mutations in the phospholipase C δ 1 (PLCD1) gene have been reported. The present study reports on one Chinese family and one sporadic case of with HL. The family members exhibited an autosomal dominant pattern of inheritance with the involvement of all the fingers and toenails in all the patients. Of interest, most of the affected members had koilonychia during their childhood. Thus, the present study first used gene mapping with an aim to identify the pathogenic gene underlying koilonychia. Through genome­wide linkage analysis, the pathogenic area of koilonychia was identified on chromosome 3 with multipoint Log of Odds scores >2. A novel pathogenic mutation c.1384G>A (p.E462K) was identified in the PLCD1 gene in all the patients in the family, which confirmed the diagnosis of hereditary leukonychia. A novel mutation c.770G>A (p.R257H) was also detected in one sporadic case of leukonychia. On the basis of these findings and of previous studies, it is suggested that hereditary leukonychia may initially present as koilonychia, whereas hereditary koilonychia does not progress to leukonychia. Moreover, the present study identified two pathogenic variants of the PLCD1 associated with hereditary leukonychia, and highlights the significance of genetic diagnosis.

A case of idiopathic acquired leukonychia totalis in a 17-year-old boy.

Whitening of the nail, or leukonychia, can have a wide range of etiologies including genetic disorders, trauma, poisoning, autoimmune disorders, and infections. Here we detail a case of idiopathic acquired leukonychia totalis in a 17-year-old boy. This condition has been reported 13 times in the literature previously, with only young boys being affected. Proper diagnosis may help minimize unnecessary investigations and prevent additional psychological stress over whether an underlying disease is present.

PLACK syndrome is potentially treatable with intralipids.

We describe an 11-year-old girl with PLACK Syndrome (peeling skin, leukonychia, acral punctate keratosis, cheilitis, and knuckle pads), who was found to have a novel homozygous variant in CAST, the pathogenicity of which was confirmed using blood-derived RNA. There is no established treatment for PLACK syndrome. However, we demonstrate for the first time that this condition is associated with low levels of vitamin A and essential fatty acids, which prompted us to consider a potential treatment strategy. Indeed, we initiated this patient on intravenous lipid infusion (Vitalipid®; an emulsion of fat-soluble vitamins and lipofundin-MCT/LCT 20%) and the response was dramatic. Following the fourth monthly course of treatment, pruritis disappeared and the skin lesions showed remarkable objective improvement. PLACK syndrome is a very rare genodermatosis and only six families have been described to date with pathogenic CAST variants. This is the first report of an objective response to a therapeutic agent, which suggests that PLACK is a potentially treatable condition. The remarkable response we report and the relative safety of the intervention should prompt healthcare providers who care for PLACK syndrome patients to explore this as a potential treatment strategy in future studies.

Developmental delay, intellectual disability, short stature, subglottic stenosis, hearing impairment, onychodysplasia of the index fingers, and distinctive facial features: A newly reported autosomal recessive syndrome.

We report on a multiply consanguineous Syrian family where two siblings, a boy and a girl, presented with a compilation of symptoms including developmental delay, severe intellectual disability, absent speech, hearing impairment, short stature, subglottic stenosis, increased length of the palpebral fissures, onychodysplasia of index fingers, scoliosis, genu valgum, and malpositioned toes. Two other individuals from the extended family with similar clinical features are also described. Array-CGH did not reveal any pathological copy number variation. Exome sequencing failed to find any causal variants. Differential diagnoses and the possibility that we might be reporting a hitherto unknown syndrome are discussed.

Uñas de pies en «salto de esquí» / Ski-Jump Toenails

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Paediatric nail consultation in an academic centre in Belgium: a 10-year retrospective study.

BACKGROUND: Very few studies have been conducted to establish the nature and prevalence of nail disorders in children. OBJECTIVES: To determine the frequency of various nail conditions in the paediatric setting and to report their management and follow-up. METHODS: This was a retrospective study between 2007 and 2017 of children under 18. All the patients were evaluated in our paediatric nail clinic at the dermatology department of Queen Fabiola Children's University Hospital. The data were synthesized from information obtained through medical records as well as from photographs taken during consultation. Follow-up was completed by phone interview. RESULTS: Three hundred and one patients were included. The majority of nail abnormalities involved the toenails (57.6%). The most common clinical signs were, in descending order, Beau's lines, pachyonychia, subungual hyperkeratosis and onycholysis. The most frequent diagnoses were fever-related Beau's lines or onychomadesis (9.7%), trachyonychia (8.4%), longitudinal melanonychia (8.1%) and congenital malalignment of the great toenail (8.1%). The main diagnoses by age group were as follows: congenital hypertrophy of the lateral nail folds (21.4%) [0-2 years old]; fever-related Beau's lines or onychomadesis (21%) [2-6 years old]; trachyonychia (22%) [6-12 years old]; and juvenile ingrown nail (21.4%) [12-18 years old]. Management included clinical observation for 119 patients and specific advices for 108 patients. A treatment was prescribed for 134 patients, topical in 76.5% of cases. Follow-up demonstrated complete healing in 50.6% of patients and improvement in 19.7%. CONCLUSION: The most frequent nail disorders are benign, and their distribution varies with age. Management mainly involves conservative care, and the prognosis is favourable in the majority.

Identification of a novel PLCD1 mutation in Chinese Han pedigree with hereditary leukonychia and koilonychia.

BACKGROUND: Hereditary leukonychia is a rare nail dystrophy characterized by distinctive whitening of the nail plate. Mutations in the PLCD1 gene have been identified as a major causative factor in hereditary leukonychia (HL). However, few reports have analyzed the relationship between genotype and phenotype, especially in Chinese HL patients. Our study aims to explore the typical clinical features of hereditary leukonychia cases in Chinese Han pedigree and the correlations with PLCD1 gene mutation. PATIENTS AND METHODS: In this study, two Chinese patients presented with leukonychia and koilonychia. Whole-exome sequencing (WES) was performed to screen for the mutations in PLCD1 gene and other candidate genes for hereditary leukonychia. Parents with PLCD1 mutation were selected for Sanger sequencing. RESULTS: A novel heterozygote missense mutation in exon 9 of PLCD1 gene was identified in the proband and his mother. Whole-exome sequencing revealed both, the proband (III.5) and his mother (II.4) carrying c.1451A>G mutation, while other family members had a normal sequence of the PLCD1 gene. CONCLUSION: For the first time, a hereditary leukonychia case with PLCD1 mutation has been described in Chinese Han pedigree. This finding suggests the PLCD1 mutation maybe involved in hereditary leukonychia.

Whole exome sequencing identifies a novel dominant missense mutation underlying leukonychia in a Pakistani family.

Hereditary leukonychia (also known as porcelain nails or white nails) is a genetic disorder. It may exist as an isolated feature or associated with other cutaneous or systemic disorders. Although a number of genes have been described to cause leukonychia, still the underlying genetic etiologies of many cases remain unknown. Here, we report a Pakistani family presenting leukonychia and koilonychia nails in mother and five of her kids. All the affected individuals had white to pale nails in appearance exhibiting complete and partial leukonychia, respectively. Similarly, nails of finger and toe appeared brittle and concave, showing the characteristics features of koilonychia. Whole exome sequencing and subsequent Sanger sequencing identified a pathogenic novel missense mutation (c.1390G>A, p.Glu464Lys) in PLCD1, co-segregating with the disorder in an autosomal dominant pattern. In silico prediction tools supported the pathogenicity of the identified mutation. Literature review determined that mutations in PLCD1 only cause leukonychia. Therefore, our findings add another pathogenic variant to the PLCD1 mutation pool causing leukonychia that would help to understand the underlying molecular mechanism.

Síndrome de Iso-Kikuchi: 3 casos en la edad pediátrica / Iso-Kikuchi Syndrome: Report of 3 Pediatric Cases

El síndrome de Iso-Kikuchi, onicodisplasia congénita del dedo índice, es una entidad poco frecuente caracterizada por la anoniquia total o displasia de la uña del dedo índice, acompañado, en algunas ocasiones, de alteraciones óseas subyacentes, por lo general, en ausencia de otras anomalías. Si bien se han planteado distintas hipótesis fisiopatogénicas, la etiología sigue siendo desconocida. Describimos los casos de 3 pacientes pediátricos, 2 varones y una niña, con alteraciones ungueales y óseas compatibles con el síndrome de Iso-Kikuchi. Destacamos la importancia de reconocer esta entidad tempranamente para evitar la realización de estudios complementarios y terapéuticas innecesarias

Iso-Kikuchi syndrome, or congenital onychodysplasia of the index finger, is an uncommon condition characterized by total anonychia or dysplasia of the nail of the index finger. It is occasionally accompanied by underlying bone abnormalities and is rarely associated with other conditions. Although various hypotheses have been put forward to explain the pathophysiology of the syndrome, its etiology remains unknown. We report the cases of 3 pediatric patients (2 boys and 1 girl) with nail changes and bone abnormalities consistent with Iso-Kikuchi syndrome. We highlight the importance of recognizing this entity early to avoid the need for additional tests and unnecessary treatment