Pemphigus is a group of autoimmune mucocutaneous bullous disorders characterized by acantholysis resulting from autoantibodies targeting epithelial cell surface antigens. Studies reflect the presence of nail manifestations in some patients and suggest a potential correlation with clinical severity. This study examines the overall prevalence and characterizes the diverse manifestations of nail changes in pemphigus. We searched Cochrane, MEDLINE, EMBASE, and LILACS from 1990 to June 26, 2023 for studies reporting different nail changes in pemphigus patients. Data were collected and pooled to obtain proportions of the prevalence of nail changes in patients with pemphigus and subgroup analysis for pemphigus foliaceous and pemphigus vulgaris. The risk of bias was assessed with the Joanna Briggs Institute Checklist. Of 321 studies screened, 14 studies with 1,208 patients were included. Paronychia (n = 185) and Beau\'s lines (n = 104) were the most common nail changes identified. The pooled prevalence of nail disease in pemphigus patients was 0.389 (number of studies; [95% CI]: n = 9; [0.160-0.680], with high heterogeneity between studies (I2 = 95.0%, P < 0.001). Subgroup analysis revealed the highest prevalence in pemphigus foliaceous at 0.342 (n = 3; [0.109-0.688]) and pemphigus vulgaris at 0.396 (n = 5; [0.114-0.769]). Nail changes exhibited varied temporal relationships with disease onset and flares, preceding, concurrent, or following these events. Correlation with disease severity was noted, although discrepancies between studies were reported. Nail changes in pemphigus, particularly pemphigus vulgaris and pemphigus foliaceous, may be underrecognized. Observations regarding temporal associations and potential correlations with disease severity highlight the diagnostic and prognostic implications of nail changes in pemphigus. The limitations of this study include study heterogeneity and possible bias. Further research to establish the correlation of the presence and severity of nail changes on the overall disease course would be helpful.

Background: Long bones are commonly affected by musculoskeletal tumors, but they also represent one of the most frequent locations for metastases. The treatment is based on pain management and the prevention or stabilization of pathological fractures by intramedullary nailing. While titanium nails are probably the most used, carbon-fiber-reinforced (CFR) nails have emerged as a new option for oncological patients. The aim of this review is to compare titanium and CFR nails according to current findings. Methods: Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) standards were followed: a total of 1004 articles were identified and 10 were included. Results: Traditionally, titanium implants are highly valued for their optimal biomechanical properties and ease of insertion, facilitated by their radiopacity. However, the use of titanium poses challenges in radiotherapy due to interference with radiation dosage and the creation of ferromagnetic artifacts. Conversely, CFR implants have emerged as a recommended option for intramedullary fixation, due to their biomechanical and structural properties and their benefits during radiotherapy and follow-up monitoring X-ray. Conclusions: CFR nailing represents a promising advancement in the surgical management of oncological patients with long bone metastases. However, further studies are needed to increase surgeons\' confidence in their use.

Squamous cell carcinoma of the nail unit (nSCC) is a rare malignant tumor of the hand and nail. Although skin cancer rarely affects individuals with phototypes IV-VI, its occurrence in these groups is often associated with greater morbidity and mortality. This study aims to characterize the clinical symptoms, presentations, and treatments of nSCC in patients with darker skin types. A systematic review of PubMed and Embase was performed in May 2023 for all peer-reviewed, English-language nSCC studies involving individuals with Fitzpatrick types IV-VI. Most tumors were located on the fingernails (84%), with the right third finger being the most frequently affected (31%). The nail bed (67%) exhibited a higher prevalence than the lateral/proximal nail folds (33%). The duration of symptoms before diagnosis ranged from 1 month to 7 years. nSCC was most commonly treated with Mohs surgery (38%), followed by amputation (35%). Our study was limited to case reports because of a lack of large nSCC studies that provide information on race or images of each patient. These tumors are generally slow-growing yet often misdiagnosed, leading to delays in presentation and diagnosis. Increased awareness about nSCC in phototype IV-VI individuals will reduce misdiagnoses, unnecessary treatment, and recurrences.

Subungual Onycholemmal Cyst (SOC) is a rare nail abnormality with different clinical presentations which can mimic different nail malignancies, such as melanoma, SCC, or glomus tumor. It is necessary for dermatologists and dermatopathologist to be aware of this pathology to make the proper diagnosis and treatment. SOC is a rare nail abnormality which affects the dermis of the nail bed. SOC has different clinical presentations, including onychodystrophy, ridging, clubbing, thickening, pigmentation, or even normal appearance. It can mimic different nail malignancies, such as melanoma, SCC, or glomus tumor. In this report, we describe a 54-year-old man with unilateral second right finger nail onychodystrophy and onycholysis for 1 year. He did not have any history of recent trauma, pain, or bleeding. It was completely resected by surgery. Nail biopsy can contribute to the early diagnosis of SOC and improvement of treatment outcomes.

UNASSIGNED: Gout is a depositional, inflammatory disorder that is rarely reported to affect the nail unit. Cases of gout involving the nail unit are likely under-recognized and therefore underreported. We present two cases of tophaceous gout affecting the nail unit and a literature review of the various presentations.
UNASSIGNED: Five cases of gout were identified to affect the nail unit. In all cases, these presented as white hyperkeratotic papulonodules with associated nail dystrophy. Chalky discharge was seen in three of the five cases. Nine cases were identified to have demonstrated pseudocarcinomatous changes that histopathologically mimic squamous cell carcinoma (SCC). Literature review highlights a range of findings including subclinical deposits of uric acid in the nail, onychoschizia, onychorrhexis, and Beau\'s line.
UNASSIGNED: Physicians should be aware of the subtle and nonspecific clinical findings of gout, which may be easily misconstrued for other pathological entities.

UNASSIGNED: Vitamins have gained popularity among physicians and patients for purported benefits to hair, skin, and nail health. Safe and efficacious therapies for nail disorders, many of which are chronic conditions, are needed.
UNASSIGNED: We conducted a literature review of studies assessing the efficacy of oral, topical, and intralesional vitamin/vitamin derivatives for the treatment of nail disorders, including yellow nail syndrome, brittle nail syndrome, onychomycosis, habit-tic nail deformity, periungual/subungual verruca, and nail psoriasis. Forty-nine articles were reviewed. There is good evidence to support the use of topical tazarotene and vitamin D analogs for nail psoriasis treatment. We found overall limited evidence for treatment of other nail disorders with vitamin/vitamin derivatives, and further research is needed to support their use.
UNASSIGNED: Besides topical tazarotene and vitamin D analogs for nail psoriasis treatment, there is limited evidence for treatment of nail disorders with topical, oral, and intralesional vitamin/vitamin derivatives.

UNASSIGNED: Kaposi sarcoma is an angioproliferative neoplasm. Its manifestations are well known but nail involvement seems extremely underreported.
UNASSIGNED: A 55-year-old man presented with a 6-month history of a growing subungual tumor affecting the third right toe. After surgical excision, histological examination revealed a Kaposi sarcoma.
UNASSIGNED: We report a case of Kaposi sarcoma with nail involvement of only one toe as the first and unique manifestation, which is exceptional.

Recalcitrant nail plate infections can be life-long problems because localizing antifungal agents into infected tissues is problematic. In this systematic review, guided by the SPIDER method, we extracted chemical nail permeation data for 38 compounds from 16 articles, and analyzed the data using quantitative structure-property relationships (QSPRs). Our analysis demonstrated that low-molecular weight was essential for effective nail penetration, with <120 g/mol being preferred. Interestingly, chemical polarity had little effect on nail penetration; therefore, small polar molecules, which effectively penetrate the nail, but not the skin, should be set as the most desirable target chemical property in new post-screen onychomycosis candidate selections.

Lichen planus is a chronic inflammatory disorder that may affect the skin, nails, and/or oral mucosa. Bullous lichen planus is a rare variant of lichen planus, which is even less common in the nails. We present a case of nail bullous lichen planus, in a 48-year-old male presenting with a 10-month history of onychodystrophy of all ten fingernails. A longitudinal excision of the left thumbnail was performed, with histopathology consistent with lichen planus with focal transition to bullous lichen planus. He was treated with intralesional triamcinolone injections to the fingernails monthly, with improvements noted after three treatments. Our patient\'s nail bullous lichen planus manifested with longitudinal ridging, white-yellow discoloration, onycholysis, subungual hyperkeratosis, and v-shaped nicking. Histopathological findings included classical lichen planus changes, as well as formation of subepidermal bullae, colloid bodies, and extensive inflammatory infiltrate. Increased awareness and high index of suspicion for this condition are necessary, given the often late diagnosis reported in previously published cases.

OBJECTIVE: Favipiravir is an antiviral agent, recently used for COVID-19 infections. Several reports associate favipiravir intake with Wood\'s lamp fluorescence of hair, nails, and sclera. The present study was designed to elucidate the positivity rates, and sites of favipiravir-related fluorescence and to unravel the site-specific changes in fluorescence positivity rates by a function of time past exposure.
METHODS: The study population comprised 50 patients and 50 control individuals. All patients in the patient group had received a full dose of favipiravir for COVID-19 infection. Fifty volunteers served as the control group. Wood\'s lamp examination was performed in a completely darkened room, and the positivity rate, extent, pattern, and distribution of fluorescence were recorded.
RESULTS: Wood\'s light revealed fluorescence of the fingernails, toenails, sclera, and hair in 35 (70%), 35 (70%), 22 (44%), and 8 (16%) patients, respectively. No control individual tested positive by Wood\'s lamp. Statistical analysis revealed significant differences between patient and control groups in terms of Wood\'s light luminescence in the fingernails (p = .000), toenails (p = .000), sclera (p = .000) and hair (p = .003). Although fingernail, toenail, and hair fluorescence positivity rates declined or ceased at or after 91 days of favipiravir exposure, ocular fluorescence positivity rates were prolonged up to 188 days.
CONCLUSIONS: These findings confirm that favipiravir may produce fluorescence of nails, sclera, and hair, detectable by Wood\'s light starting from the initial month and peaking at second- and third months following exposure to the medication. Although nail and hair fluorescence tend to abate after 3 months, ocular fluorescence may persist even longer than 6 months after cessation of the medication.