Self-improving dystrophic epidermolysis bullosa with a novel heterozygous missense variant in the COL7A1 gene in a Taiwanese family.

Self-improving dystrophic epidermolysis bullosa (DEB) is a genodermatosis that is inherited autosomal dominantly or recessively, and its clinical symptoms may improve or subside spontaneously. Herein, we report a case of self-improving DEB with COL7A1 p.Gly2025Asp variant. The diagnosis was made through histopathological, electron microscopic examination, and genetic testing. The same variant is also noted on his father, who presents with dystrophic toenails without any blisters. This study highlights that idiopathic nail dystrophy could be linked to congenital or hereditary disease. Furthermore, we conducted a review of the literature on the characteristics of reported cases of self-improving DEB with a personal or family history of nail dystrophy. The results supported our findings that nail dystrophy may be the sole manifestation in some family members. We suggest that individuals suffering from idiopathic nail dystrophy may seek genetic counselling when planning pregnancy to early evaluate the potential risk of hereditary diseases.

Residential proximity to toxic metal-emitting industrial sites and toenail metal concentrations in a United States-wide prospective cohort.

BACKGROUND: Industrial facilities across the United States (US) release millions of pounds of toxic chemicals, including metals. Exposure to toxic metals has been associated with adverse health outcomes, but there is limited evidence on the association between living near metal-releasing facilities and the body burden of emitted compounds. OBJECTIVE: To investigate the association between residential proximity to toxic metal-emitting industrial facilities and toenail metal concentrations and to evaluate whether associations differed by race. METHODS: In a sample of 1556 non-Hispanic Black (32.5%) and non-Hispanic White (67.5%) women from the Sister Study, we used the US Environmental Protection Agency Toxics Release Inventory to identify metal-emitting facilities within 3, 5, and 10 km of participants' baseline residences. We measured toenail concentrations (µg/g) of arsenic, cadmium, cobalt, chromium, and lead. Using multivariable linear regression, we examined associations between residential proximity to and emissions from metal-emitting facilities and toenail metal concentrations, stratifying by race. We explored modification of race-stratified associations by neighborhood deprivation, using the Area Deprivation Index (ADI). RESULTS: Black participants were more likely to reside within 3 km of chromium-releasing facilities and 5 and 10 km of all observed metal-emitting sites. Living near metal-releasing facilities was not associated with higher toenail metal concentrations overall. Among Black women, higher chromium emissions exposure was associated with higher toenail chromium levels (ßTertile3vs.non-exposed = 2.36 µg/g, 95% CI = 0.63, 4.10). An association with lead was observed among Black women residing in the most deprived areas (≥75th ADI percentile: ß = 3.08 µg/g, 95% CI = 1.46, 4.71). No associations were observed for White participants. CONCLUSIONS: Despite low exposure prevalence, our findings suggest that living near chromium- and lead-releasing facilities, especially at shorter distances, may be associated with higher corresponding toenail metal levels among Black women, particularly those residing in the most disadvantaged areas.

Toenail zinc and risk of prostate cancer in the MCC-Spain case-control study.

BACKGROUND: Some researchers have suggested that zinc (Zn) could reduce the risk of prostate cancer (PC). However, research from observational studies on the relationship between PC risk and biomarkers of Zn exposure shows conflicting results. OBJECTIVES: To evaluate the association between toenail Zn and PC, considering tumour extension and aggressiveness, along with a gene-environment approach, exploring the interaction of individual genetic susceptibility to PC in the relationship between toenail Zn and PC. METHODS: In MCC-Spain study we invited all incident PC cases diagnosed in the study period (2008-2013) and recruited randomly selected general population controls. In this report we included 913 cases and 1198 controls with toenail Zn determined by inductively coupled plasma mass spectrometry. To measure individual genetic susceptibility, we constructed a polygenic risk score based on known PC-related single nucleotide polymorphisms. The association between toenail Zn and PC was explored with mixed logistic and multinomial regression models. RESULTS: Men with higher toenail Zn had higher risk of PC (OR quartile 4 vs.1: 1.41; 95% CI: 1.07-1.85). This association was slightly higher in high-grade PC [(ISUP≤2 Relative risk ratio (RRR) quartile 4 vs.1: 1.36; 1.01-1.83) vs. (ISUP3-5 RRR quartile 4 vs.1: 1.64; 1.06-2.54)] and in advanced tumours [(cT1-cT2a RRR quartile 4 vs.1: 1.40; 95% CI: 1.05-1.89) vs. (cT2b-cT4 RRR quartile 4 vs.1: 1.59; 1.00-2.53)]. Men with lower genetic susceptibility to PC were those at higher risk of PC associated with high toenail Zn (OR quartile 4 vs.1: 2.18; 95% CI: 1.08-4.40). DISCUSSION: High toenail Zn levels were related to a higher risk for PC, especially for more aggressive or advanced tumours. This effect was stronger among men with a lower genetic susceptibility to PC.

Comparison of dermoscopic characteristics on toenail onychomycosis in psoriatic and non-psoriatic patients: A prospective study.

BACKGROUND: Psoriatic patients may experience the coexistence of onychomycosis (OM). However, the evaluation of OM in psoriatics has been hindered by potential clinical differences from OM in non-psoriatics. OBJECTIVE: To assess and compare dermoscopic features between toenail OM in psoriatic and in non-psoriatic patients. PATIENTS AND METHODS: Between September 2020 and September 2023, dermoscopy was conducted on 183 affected toenails by OM in psoriatics and 232 affected toenails by OM in non-psoriatics in two centres. The dermoscopic characteristics were compared using the Chi-squared test. RESULTS: Among toenail OM cases in psoriatic subjects, the most prevalent dermoscopic features included pitting (147/183, 80.33%) and subungual hyperkeratosis (118/183, 64.48%). Conversely, toenail OM in non-psoriatics was characterized by subungual hyperkeratosis (175/232, 75.43%) and nail spikes (139/232, 59.91%). Comparative analysis revealed a significantly higher occurrence of pitting (80.33% vs. 15.96%, p < .001), periungual telangiectasis (22.40% vs. 4.74%, p < .001), oil patches (12.57% vs. 0.43%,p < .001) and transverse grooves (43.72% vs. 28.45%,p < .01) in toenail OM in psoriatics. Furthermore, toenail OM in psoriatics exhibited a significantly lower frequency of yellow structureless area (13.11% vs. 42.67%, p < .001), nail spikes (43.17% vs. 59.91%, p < .01), ruin appearance of sulphur nugget (8.20% vs. 31.03%, p < .001), dotted/blocky haemorrhage (6.01% vs. 20.69%,p < .001) and partial onycholysis (32.79% vs. 46.98%, p < .01). CONCLUSIONS: Dermoscopic features of toenail OM in psoriatic and non-psoriatic patients exhibit notable differences. OM in psoriatics shows a higher frequency of pitting and periungual telangiectasis, while a lower frequency of yellow structureless areas and nail spikes under dermoscopy.

Onychoscopic characteristics of Trichophyton rubrum and Trichophyton interdigitalis fungal infections: A multicentric study.

BACKGROUND: Trichophyton rubrum and Trichophyton mentagrophytes variant interdigitalis are the most frequent etiologic agents of onychomycosis. Diagnosis of certainty requires mycological examination, which often results unfeasible. OBJECTIVES: The aim of our study is to describe pathogen specific dermoscopic features, allowing a differential diagnosis without the need for cultural examination, in order to prescribe the most appropriate treatment anyway. PATIENTS AND METHODS: We conducted an observational retrospective study on 54 patients with a culture proven diagnosis of distal subungual onychomycosis of the toenail, caused by Trichophyton rubrum or Trichophyton mentagrophytes variant interdigitalis. Using a videodermatoscope we collected data on nail colour (white, yellow, orange, brown, dark) and on dermoscopic patterns (aurora, spikes, jagged, ruin, linear edge, dots, striae). RESULTS: Fifty-four patients, with a total of 72 nails, were eligible for this study. Analysing the association between discoloration of the nail plate and type of infection (T. rubrum or T. interdigitalis), no correlation turned out to be statistically significant. Instead, significant associations between spikes and T. rubrum infection and striae and infection from T. interdigitalis were identified. Finally, a 100% specificity was identified for white colour and ruin pattern for T. rubrum infection, and brown colour, jagged border and aurora pattern for T. interdigitalis. CONCLUSIONS: Trying to find relationships between specific pathogens and dermoscopic patterns, we found out an association between spikes and striae and T. rubrum and T. interdigitalis respectively. Further larger studies are however necessary to evaluate our preliminary findings.

Association between lead and circulating markers of inflammation among traffic enforcers in Metro Manila, Philippines: the MMDA traffic enforcer's health study.

PURPOSE: Several epidemiological studies have linked lead (Pb) exposure to induced oxidative stress and the promotion of inflammatory response. We performed a within-subjects study (repeated measures study) to evaluate the relationship between the concentration of blood lead (B-Pb) and toenail lead (T-Pb) and circulating markers of inflammation. METHODS: We evaluated the associations between B-Pb concentrations and T-Pb concentrations and circulating markers of inflammation, soluble intracellular adhesion molecule-1 (s-ICAM-1), soluble vascular adhesion molecule-1 (s-VCAM-1), and high-sensitivity C-reactive protein (hs-CRP) on 158 traffic enforcers from the Metropolitan Manila Development Authority (MMDA) traffic enforcer's health study. Linear mixed-effects models with random subject-specific intercepts were fitted to estimate the association between B-Pb and T-Pb exposure and circulating markers of inflammation, adjusting for confounding factors. RESULTS: Traffic enforcers were middle-aged men (89.4%) with a mean age (± SD) of 37.1 years ± 8.9 years and had a total of 293 valid markers of inflammation measurements. B-Pb concentration was related to increased hs-CRP levels. A 10% increase in B-Pb was associated with a 5.7% increase in hs-CRP level [95% confidence interval (95% CI): 1.3-10.1]. However, B-Pb was not associated with s-ICAM-1 and s-VCAM-1. Furthermore, no associations were observed between T-Pb and all the circulating markers of inflammation. CONCLUSIONS: Low-level B-Pb may increase hs-CRP among traffic enforcers. Moreover, the study suggests that Pb via the oxidative and inflammation pathways may have an essential role in the development of cardiovascular disease. Furthermore, MMDA and the Department of Labor and Employment can use our study's findings as evidence to conduct routine screening of blood heavy metals, especially Pb, among MMDA and other traffic enforcers as part of their yearly medical examination.

Reconstruction of Allen's type IV fingertip amputation via bilateral unequal-sized hallux osteo-onychocutaneous free flaps: A retrospective study with 5-year follow-up.

PURPOSE: The reconstruction of Allen's type IV fingertip amputation is a clinical challenge. Our team designed bilateral unequal-sized hallux osteo-onychocutaneous free flaps for the long-term reconstruction of Allen's type IV fingertip amputation and conducted a retrospective study with a 5-year follow-up aims to evaluate the effects of this technique. METHODS: A retrospective analysis with a 5-year follow-up including 13 patients with Allen's type IV fingertip amputation who were admitted to our hospital from January 2010 to January 2017 was conducted. The patients were treated with bilateral unequal-sized hallux osteo-onychocutaneous free flaps. The operation time, intraoperative blood loss, and complications were recorded, and the survival rate of the transplanted flaps was calculated. During the 5-year follow-up after operation, the nail growth time was recorded and the finger appearance was observed. At the last follow-up appointment, the length, width, and girth of the reconstructed fingertip and contralateral normal fingertip, range of motion of the reconstructed fingertip and contralateral normal fingertip, Semmes-Weinstein test (for the evaluation of tactile sensation), and two-point discrimination testing results were recorded. SPSS 22.0 software was used for the statistical analysis and the data are presented as mean ± SD. RESULTS: The mean operation time was (5.62 ± 0.51) h, the mean intraoperative blood loss was (34.15 ± 3.13) mL, and the survival rate of the transplanted flaps was 100%. During the 5-year follow-up, the average nail growth time was (10.14 ± 1.98) months and the average bone union time was (3.78 ± 0.91) months. The length, width, and girth of the reconstructed fingertip were (31.52 ± 3.73) mm, (17.82 ± 1.74) mm, and (59.75 ± 3.04) mm, respectively, which did not differ from those of the contralateral normal fingertip. The range of motion of the reconstructed fingertip was (12.15 ± 2.79) degrees which is different from that of the contralateral normal fingertip. The average tactile sensation evaluated via the Semmes-Weinstein test and the average two-point discrimination test of the reconstructed fingertip were (0.39 ± 0.17) g and (7.46 ± 1.14) mm, respectively, which were not different from those of the contralateral normal fingertip. The average Maryland score of feet in the donor area was 87.66 ± 7.39, which was satisfactory. CONCLUSION: Bilateral unequal-sized hallux osteo-onychocutaneous free flaps are an effective method to reconstruct Allen's type IV fingertip amputations with a satisfactory appearance and good sensory function.

A comparative study on the efficacy between omega toenail correction and winograd procedure for stage II-III paronychia.

The objective of this study is to conduct a prospective trial comparing the therapeutic efficacy of Omega toenail correction and the Winograd procedure in treating stage II-III paronychia. From August 2018 to August 2023, ninety cases from eighty-three patients were randomly divided into two groups, one receiving Omega toenail correction (experimental group) and the other receiving the Winograd procedure (control group). The clinical therapeutic effects of both treatments were evaluated based on time to resume movement, treatment cycle, one-year recurrence rate, and visual analogue scale (VAS) scores before and after treatment. The clinical efficacy was compared between Omega toenail correction and Winograd procedure treating paronychia of stage Ⅱ-Ⅲ. It has been demonstrated that the time to resume movement in the experimental group is obviously shorter than that in the control group (P = 0.024), while the treatment cycle is longer (P = 0.009) with no significant difference (P = 0.734) in the aspect of one-year recurrence rate. However, the VAS after the correction in the experimental group is significantly lower than that in the control group (P = 0.019). It has been suggested that Omega toenail correction characterized by easy operation, sure efficacy and lower recurrence rate can be widely applied in clinic work.

Epigenome-wide DNA methylation in leukocytes and toenail metals: The normative aging study.

BACKGROUND: Environmental metal exposures have been associated with multiple deleterious health endpoints. DNA methylation (DNAm) may provide insight into the mechanisms underlying these relationships. Toenail metals are non-invasive biomarkers, reflecting a medium-term time exposure window. OBJECTIVES: This study examined variation in leukocyte DNAm and toenail arsenic (As), cadmium (Cd), lead (Pb), manganese (Mn), and mercury (Hg) among elderly men in the Normative Aging Study, a longitudinal cohort. METHODS: We repeatedly collected samples of blood and toenail clippings. We measured DNAm in leukocytes with the Illumina HumanMethylation450 K BeadChip. We first performed median regression to evaluate the effects of each individual toenail metal on DNAm at three levels: individual cytosine-phosphate-guanine (CpG) sites, regions, and pathways. Then, we applied a Bayesian kernel machine regression (BKMR) to assess the joint and individual effects of metal mixtures on DNAm. Significant CpGs were identified using a multiple testing correction based on the independent degrees of freedom approach for correlated outcomes. The approach considers the effective degrees of freedom in the DNAm data using the principal components that explain >95% variation of the data. RESULTS: We included 564 subjects (754 visits) between 1999 and 2013. The numbers of significantly differentially methylated CpG sites, regions, and pathways varied by metals. For example, we found six significant pathways for As, three for Cd, and one for Mn. The As-associated pathways were associated with cancer (e.g., skin cancer) and cardiovascular disease, whereas the Cd-associated pathways were related to lung cancer. Metal mixtures were also associated with 47 significant CpG sites, as well as pathways, mainly related to cancer and cardiovascular disease. CONCLUSIONS: This study provides an approach to understanding the potential epigenetic mechanisms underlying observed relations between toenail metals and adverse health endpoints.

The reconstruction of fingertip injury by mini hallux toenail flap pedicled with the hallux transverse artery and toe pulp vein transplantation technique based on the equivalent design theory.

INTRODUCTION: How to reconstruct the damaged fingertip is a clinical problem. Our team propose the theory of equivalent design and use the mini toenail flap pedicled with the hallux transverse artery and toe pulp vein transplantation technique to reconstruct Allen's type II fingertip injury. Thus, we perform the retrospective study to evaluate the effects of this technique on fingertip injury. MATERIALS AND METHODS: A retrospective analysis was performed on 56 patients admitted to our hospital from January 2015 to January 2020 who used equivalently designed miniature hallux toenail flaps for the plastic repair of fingertip damage. We recorded the size of the miniature hallux toenail flap, operation time, intraoperative blood loss, and complications and calculated the survival rate of the transplanted miniature hallux toenail flap. During routine follow-up after surgery, we recorded nail growth time and observed finger appearance. At the last time of follow-up, we recorded Semmes-Weinstein evaluating tactile sensation and Two-point discrimination testing (TPD). The efficacy was evaluated by Zook score evaluation. RESULTS: The size of the mini hallux toenail flap was 0.71 cm × 1.22 cm to 0.88 cm × 1.71 cm. The operation time was (3.54 ± 0.58) hours, the intraoperative blood loss was (20.66 ± 4.87) ml, and the survival rate of mini hallux toenail flaps was 100%. The postoperative follow-up time was (30.82 ± 11.21) months, and the total nail growth time was (9.68 ± 2.11) months. The average tactile sensation evaluated by the Semmes-Weinstein test was (0.32 ± 0.14) g, and the average TPD was (7.33 ± 1.02) mm. According to Zook score, the curative effect of fifty-six cases were all excellent or good with 100% excellent and good rate, and all patients had beautiful appearances and good function of damaged fingertips. CONCLUSIONS: Based on the equivalent design theory, the mini hallux toenail flap pedicled with the hallux transverse artery and toe pulp vein transplantation technique is an effective method to reconstruct Allen's type II fingertip injury with a beautiful appearance and good function. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Effectiveness of hyaluronic acid in post-surgical cures following partial matricectomies with the phenol/alcohol technique: A randomized clinical trial.

BACKGROUND: Post-operative cures with hyaluronic acid (HA) could potentially shorten the period recovery involved in the phenol technique for ingrown toenail. The aim of this study was therefore to compare a standard healing protocol with the experimental one based on hyaluronic acid cream. MATERIAL AND METHODS: 70 patients who had undergone phenol technique surgery for ingrown toenail were divided into two groups - control (n = 35) who received post-operative cures following the standard protocol with povidone iodine gel, and experimental (n = 35) who received cures with HA in the first 3 visits. Bleeding, total healing time, and perceived pain were assessed. RESULTS: Patients in the control group recovered from the intervention in a total of 26.17 ± 7.75 days, while those in the HA group recovered in a significantly shorter time - 22.42 ± 2.41 days (p = 0.007, effect size 0.653). However, there were no between-group statistical differences in bleeding or perceived pain over the course of the post-surgery visits. CONCLUSIONS: The use of low molecular weight hyaluronic acid is effective in reducing the phenol-technique healing time by 4 days compared with the standard cure. However, no extra effects such as reductions in bleeding or perceived pain can be expected in choosing this healing protocol.

A novel modified Winograd surgical tricks and tips with a "bird flap" for the treatment of ingrown toenails.

BACKGROUND: The Winograd technique is the most commonly used surgical treatment for ingrown toenails. We describe a novel modified approach, more effective and simpler to perform with a better cosmetic outcome. METHODS: We retrospectively included 45 and 39 patients with 67 and 58 ingrown toenails who underwent our modified Winograd technique and the Winograd technique, respectively, from July 2017 to June 2020, and obtained data after 3, 6, and 12 months of follow-up. RESULTS: No significant differences in the postoperative time taken to return to regular activities in the modified Winograd and traditional Winograd groups (p = 0.103) and regarding the recurrence in both groups (p = 0.055) were found. The extent of proximal germinal matrix exposure with the modified Winograd technique was significantly more clearly revealed than in the traditional Winograd method contextually (p < 0.05). The postoperative appearance satisfaction rate was significantly higher in the modified Winograd group than in the traditional Winograd group (p = 0.029). CONCLUSION: The modified Winograd technique is effective in treating ingrown toenails.

Biomarkers of disease in human nails: a comprehensive review.

Diagnostic, monitoring, response, predictive, risk, and prognostic biomarkers of disease are all widely studied, for the most part in biological fluids or tissues, but there is steadily growing interest in alternative matrices such as nails. Here we comprehensively review studies dealing with molecular or elemental biomarkers of disease, as opposed to semiological, pharmacological, toxicological, or biomonitoring studies. Nails have a long history of use in medicine as indicators of pathological processes and have also been used extensively as a matrix for monitoring exposure to environmental pollution. Nail clippings are simple to collect noninvasively as well as to transport and store, and the matrix itself is relatively stable. Nails incorporate, and are influenced by, circulating molecules and elements over their several months of growth, and it is widely held that markers of biological processes will remain in the nail, even when their levels in blood have declined. Nails thus offer the possibility to not only look back into a subject's metabolic history but also to study biomarkers of processes that operate over a longer time scale such as the post-translational modification of proteins. Reports on ungual biomarkers of metabolic and endocrine diseases, cancer, and psychological and neurological disorders will be presented, and an overview of the sampling and analytical techniques provided.

Metal Exposures in Residents Living Near an Urban Oil Drilling Site in Los Angeles, California.

Urban environmental justice communities are potentially exposed to multiple toxic metals, through contaminated air, soil, water, and food. However, information on metals and their sources is lacking. This study uses non-negative matrix factorization (NMF) in a community-based participatory research study to identify potential sources and to understand how these metals cluster in a population near an urban oil drilling site. We recruited 203 Latinx, Black, and Asian residents who lived within 1 km of an oil drilling site in south Los Angeles and collected toenail clippings to assess exposure to arsenic (As), cadmium (Cd), mercury (Hg), manganese (Mn), nickel (Ni), lead (Pb), and antimony (Sb). Using NMF, we identified three clusters based on concentrations in the participants' toenails. As, Cd, Pb, and Sb grouped together, indicative of an industrial source. A second grouping was composed of Ni and Mn, which may be related to oil drilling. We also identified a third source factor predominantly driven by Hg and As, which may arise from dietary sources. Utilizing NMF, a dimension reduction method, we identified a source factor high in Ni and Mn in residents living in a neighborhood near an active oil drilling site.

Multi-matrix biomonitoring approach to assess exposure to metals and trace elements in the Lebanese population and associations with drinking water consumption.

This study is the first attempt to assess exposure to metals and trace elements in subgroups of the Lebanese population using a multi-matrix biomonitoring approach. Concentrations of 11 metals and trace elements (aluminum (Al), arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), lead (Pb), manganese (Mn), selenium (Se), uranium (U), zinc (Zn)) were measured in urine, hair and toenails. Biological levels were compared according to age, sex, smoking status, socioeconomic status, geographical area and drinking water source. While most urinary and toenail concentrations of metals and trace elements were not different between males and females, measured concentrations of several elements in hair were higher in females compared to males. Urinary concentrations of some metals (Al, Cu, Se and Zn) were higher in children compared to teenagers and adults. Hair and toenail concentrations of several elements (As, Cd, Pb, Mn, Se in hair and toenails plus Al, Fe in toenails) were also significantly higher in children compared to teenagers and/or adults. Smoking status had no influence on metal and trace element concentrations. Levels of Cd, Pb and Mn were also higher in samples from subgroups with lower economic status (Cd and Pb in the three matrices and Mn in hair and toenails). Very few correlations were identified between sources of drinking water and urine, hair, and toenail concentrations of metals and trace elements. However, a correlation was observed between hair and toenails levels of As, Cd and Pb. Overall, results highlight that a special attention should be given to metal and trace element exposure in this population (including Pb, As, Cd, Mn, and Se). It could be relevant to scale up this kind of investigation with a large human biomonitoring initiative in the Lebanese population in order to generalize results, and assess trends over time.

Cadmium Exposure in Young Adulthood Is Associated with Risk of Nonalcoholic Fatty Liver Disease in Midlife.

BACKGROUND: Studies have suggested that cadmium (Cd) may be involved in the etiology of nonalcoholic fatty liver disease (NAFLD), but available data in human is sparse. AIMS: We aimed to examine Cd exposure in young adulthood in relation to prevalent NAFLD in midlife among American adults. METHODS: This study included 2446 participants from the Coronary Artery Risk Development in Young Adults study with toenail Cd measurement at exam year 2 (baseline) and computed tomography quantification of liver fat at exam year 25. Toenail Cd concentrations were considered as a reliable marker of long-term exposure. NAFLD was defined if liver attenuation < 51 Hounsfield units after excluding other possible causes of liver fat. Multivariable-adjusted logistic regression models were used to estimate the odds ratio of NAFLD by Cd exposure. RESULTS: Median toenail Cd concentration was 8.2 ppb (inter-quartile range 4.3-18.6 ppb). After 23 years from baseline, 580 participants with prevalent NAFLD (24% prevalence) in midlife were identified. Compared with individuals in the lowest quartile, those in the highest quartile of toenail Cd had a significantly higher odds of NAFLD (OR: 1.43, 95% CI: 1.02, 1.99, P for trend: 0.04) after adjustment for demographics, socioeconomics, major lifestyle factors, and baseline levels of body mass index, lipids, and fasting insulin. The association was not significantly modified by race, sex, BMI, or smoking status at baseline. CONCLUSIONS: Toenail Cd concentration was associated with a higher odds of prevalent NAFLD23 years later in life in this cohort of US general population.

The association between foot alignment and the development of ingrown toenails: A case-control study in a young adult military population.

BACKGROUND: This case-control study aimed to explore an association between foot alignment and development and presentation of the ingrown toenail. METHODS: Radiographs were evaluated for hallux interphalangeal angle (HIA), hallux valgus angle (HVA), talonavicular coverage angle (TNC), talo-first metatarsal (Meary's) angle, and calcaneal pitch angle (CP), as well as medial sesamoid position in a cohort of 103 young and healthy patients (mean age of 20.5 years) with ingrown toenails. A control group of 63 patients was included, and the radiographic parameters were compared. Subgroup analysis was performed in patients with lateral (n = 65) or medial (n = 38) nail fold involvement. RESULTS: The overall study group demonstrated a larger TNC and Meary's angle and smaller CP than the control group, while no significant difference was found regarding the HIA and HVA. The lateral nail fold group had a larger HIA when compared to the medial nail fold group. Multiple regression analysis revealed that for ingrown toenail development, the only risk factor was a decrease in the CP. In the case of lateral nail fold involvement, an increase in the HIA found to be the only factor. CONCLUSION: A lower medial longitudinal arch seems to be a predisposing factor in developing an ingrown toenail. The lateral nail fold involvement was associated with lateral deviation of the distal phalanx. The result of this study could provide information on prevention, treatment, recurrence, and patient counseling of an ingrown toenail in otherwise young and healthy individuals.

The use of multiple keratinous matrices (head hair, axillary hair, and toenail clippings) can help narrowing a period of drug exposure: experience with a criminal case involving 25I-NBOMe and 4-MMC.

The objective of this publication is to present the interest of collecting several keratinous specimens in order to document possible drug impairment at the time of the assault, when knowledge solely occurred 7 months after. A subject committed a murder and within minutes after the crime self-inflicted serious wounds. He was charged to the hospital where he slowly recovered. After several weeks, he was sent to prison. During this period, intelligence indicated possible drug impairment at the time of the assault after using 25I-NBOMe and 4-MMC. Head hair (4 cm), axillary hair, and toenails were collected 7 months after the crime. New psychoactive substances were tested in each specimen using LC-MS/MS, which revealed the presence of 25I-NBOMe and 4-MMC in axillary hair (2 and 6 pg/mg) and toenails (1 and 5 pg/mg). However, the perpetrator claimed that the positive findings were due to contamination in prison. Therefore, the head hair was also tested and results returned negative (LOQ at 1 pg/mg), demonstrating absence of contamination during the last 4 months before collection. Combining the window of drug detection in axillary hair (about 4 to 8 months) and the one of toenail clippings (up to 8 months), and excluding drug exposure during the previous 4 months as well as external contamination as the head hair results were negative, allowed us to conclude that the positive findings in axillary hair and toenails are more likely than not consistent with consumption of both 25I-NBOMe and 4-MMC at the time of the crime.

Toenails as a biomarker of exposure to arsenic: A review.

This systematic review summarizes the current evidence related to the reliability of toenail total arsenic concentrations (thereafter "arsenic") as a biomarker of long-term exposure. Specifically, we reviewed literature on consistency of repeated measures over time, association with other biomarkers and metal concentrations, factors influencing concentrations, and associations with health effects. We identified 129 papers containing quantitative original data on arsenic in toenail samples covering populations from 29 different countries. We observed geographic differences in toenail arsenic concentrations, with highest median or mean concentrations in Asian countries. Arsenic-contaminated drinking water, occupational exposure or living in specific industrial areas were associated with an increased toenail arsenic content. The effects of other potential determinants and sources of arsenic exposure including diet, gender and age on the concentrations in toenails need further investigations. Toenail arsenic was correlated with the concentrations in hair and fingernails, and with urine arsenic mainly among highly exposed populations with a toenail mean or median ≥1 µg/g. Overall, there is a growing body of evidence suggesting that arsenic content from a single toenail sample may reflect long-term internal dose-exposure. Toenail arsenic can serve as a reliable measure of toxic inorganic arsenic exposure in chronic disease research, particularly promising for cancer and cardiovascular conditions.

Toxic metals in toenails as biomarkers of exposure: A review.

Toenails have been used as biomarkers of exposure to toxic metals, but their validity for this purpose is not yet clear and might differ depending on the specific agent. To evaluate this issue, we reviewed the literature on: a) the time-window of exposure reflected by toenails; b) the reproducibility of toenail toxic-metal levels in repeated measures over time; c) their relationship with other biomarkers of exposure, and; d) their association with potential determinants (i.e. sociodemographic, anthropometric, or lifestyle characteristics) or with sources of exposure like diet or environmental pollution. Thus, we performed a systematic review, searching for articles that provided original data for levels of any of the following toxic metals in toenails: aluminum, beryllium, cadmium, chromium, mercury, nickel, lead, thallium and uranium. We identified 88 articles, reporting data from 67 different research projects, which were quite heterogeneous with regard to population profile, sample size and analytical technique. The most commonly studied metal was mercury. Concerning the time-window of exposure explored by toenails, some reports indicate that toenail cadmium, nickel and lead may reflect exposures that occurred 7-12 months before sampling. For repeated samples obtained 1-6 years apart, the range of intraindividual correlation coefficients of aluminum, chromium and mercury was 0.33-0.56. The correlation of toxic metal concentrations between toenails and other matrices was higher for hair and fingernails than for urine or blood. Mercury levels were consistently associated with fish intake, while other toxic metals were occasionally associated with specific sources (e.g. drinking water, place of residence, environmental pollution, and occupation). The most frequently evaluated health endpoints were cardiovascular diseases, cancer, and central nervous system diseases. Available data suggest that toenail mercury levels reflected long-term exposures and showed positive associations with fish intake. The lack of standardization in sample collection, quality control, analytical techniques and procedures - along with the heterogeneity and conflicting results among studies - mean it is still difficult to conclude that toenails are a good biomarker of exposure to toxic metals. Further studies are needed to draw solid conclusions about the suitability of toenails as biomarkers of exposure to toxic metals.