Psoriasis (PsO), psoriatic arthritis (PsA), rheumatoid arthritis (RA), and ankylosing spondylitis (AS) are chronic inflammatory disorders classified as immune-mediated inflammatory diseases (IMIDs). Although these diseases share common pathogenic mechanisms, they can affect different parts of the body. Nail involvement is important in PsO. However, nail findings in RA and AS have not been extensively investigated despite their inflammatory presentation, similar to PsO. This study aimed to investigate clinical and onychoscopic nail findings in patients with RA and AS and compare their distribution and patterns with those observed in patients with PsO and PsA. One hundred patients (25 in each group) with confirmed diagnoses of PsO, PsA, AS, and RA and at least 1 clinically detectable nail finding were included. A total of 1000 fingernails were examined clinically, and 200 fingernails were examined onychoscopically. The distributions of clinical and onychoscopic findings were assessed and compared across the 4 disease groups. Demographic data, laboratory findings (C-reactive protein, human leukocyte antigen B27, rheumatoid factor, anti-cyclic citrullinated peptide), PsO Area and Severity Index, and Nail PsO Severity Index were recorded. Pitting and onycholysis were the most common findings in PsO and PsA, leukonychia predominated in AS, and vertical ridges/trachyonychia were frequent in RA. Onychoscopy showed that clustered dotted vessels were significantly more frequent in PsO and PsA, whereas parallel dotted/short linear vessels ("fish school-like pattern") were significantly more frequent in RA. Megacapillaries, microhemorrhagic dots, and coiled and tortuous capillaries were numerically more frequent in AS. Some vascular findings were associated with elevated C-reactive protein, human leukocyte antigen B27 positivity, and rheumatoid factor positivity. Nail findings in patients with IMIDs may reflect underlying inflammatory and vascular changes. Richer nail findings in PsO and PsA may be linked to keratinocyte-driven inflammation, whereas vascular alterations may play a more prominent role in the nail findings observed in RA and AS. Differences in clinical and onychoscopic nail patterns across disease groups suggest that detailed nail examination and onychoscopy may provide supportive clinical clues and aid in the clinical differentiation of IMIDs.

Noninvasive imaging techniques are playing an increasingly significant role in dermatologic diagnosis, risk evaluation, and the monitoring of therapeutic outcomes. In the August issue of the Journal, we highlight how dermoscopy, onychoscopy, trichoscopy, and line-field confocal optical coherence tomography (LC-OCT) can refine clinical decision-making across acral melanocytic lesions, onycholysis, primary cicatricial alopecia, and hyperkeratotic actinic keratoses. These papers show that imaging is most useful when tailored to anatomical and clinical context, advancing standardized and clinically actionable imaging approaches.

Langerhans cell histiocytosis (LCH) is a rare myeloid neoplastic disorder driven by somatic MAPK pathway mutations, most commonly BRAFV600E, characterized by clonal proliferation of CD1a+/CD207+ dendritic cells forming granulomatous lesions in various tissues. Nail involvement is an uncommon but clinically significant manifestation, often associated with multisystem disease and a potentially poorer prognosis. We report 2 pediatric cases of LCH presenting with nail changes as the initial clinical feature. Case 1, a 2-year-old boy, was presented with longitudinal grooving, onycholysis, subungual hyperkeratosis, and purpuric striae of nearly all fingernails. Staging investigations revealed only mild lymphadenopathy, and BRAF mutation testing was negative. He was treated with methylprednisolone and vinblastine, achieving metabolic inactivity at 9 months. Case 2, a 19-month-old boy, was presented with diffuse fingernail and toenail dystrophy followed by cutaneous papules and was found to have multisystem disease involving bone and lungs. Nail bed, skin, and bone biopsies confirmed LCH. Systemic chemotherapy with vinblastine and prednisone led to marked improvement in nail, skin, pulmonary, and osseous lesions. These cases illustrate that nail changes may be the earliest manifestation of LCH and should prompt thorough systemic evaluation. Early recognition of nail involvement can facilitate timely diagnosis and risk-adapted treatment, potentially improving outcomes in affected patients.

Erdafitinib is a fibroblast growth factor receptor 1-4 inhibitor used for locally advanced or metastatic urothelial carcinoma in patients who have experienced disease progression after at least 1 prior systemic therapy. Various cutaneous side effects of erdafitinib have been reported, most commonly stomatitis and nail changes such as onycholysis, nail dystrophy, and paronychia. However, onychomadesis is a rarer nail toxicity that can cause significant discomfort and may necessitate treatment interruption. We present the case of a 61-year-old White man with metastatic urothelial carcinoma treated with 8 mg of erdafitinib daily who developed diffuse onychomadesis within a few months of initiating therapy. Awareness of the potential cutaneous side effects of erdafitinib and timely referral for specialty dermatologic care are important to allow treatment continuation.

Hand, foot, and mouth disease (HFMD) is a self-limiting viral illness predominantly affecting children under 10 years of age, with peak incidence in those aged one to four years. Recent outbreaks of Coxsackievirus A6 (CVA6) have increased its incidence across all age groups, including adults. Onychomadesis, a proximal nail plate detachment due to transient matrix arrest, is a recognized but underreported delayed complication of HFMD. We report a case of a 60-year-old man who developed onychomadesis three weeks after clinical recovery from CVA6-induced HFMD. Initial symptoms included fever, sore throat, gastrointestinal disturbances, and vesiculopapular lesions on the hands, feet, scalp, and oropharynx. He later presented with Beau's lines, onycholysis, and complete nail shedding involving all 10 fingernails and two toenails on each foot. Conservative management led to complete nail regrowth within eight to 12 weeks. Although the pathophysiology of HFMD-associated onychomadesis is not fully understood, potential mechanisms include direct viral cytotoxicity, localized inflammation, and systemic stress. CVA6 has been increasingly linked to adult cases, often with more severe mucocutaneous and nail manifestations compared to other serotypes. This case highlights CVA6 as an important and emerging cause of onychomadesis in adults following HFMD. Clinician awareness is essential for timely recognition, appropriate patient reassurance, and avoidance of unnecessary investigations. Further studies are needed to explain the underlying mechanisms and risk factors.

Onychopapilloma (OP) is a benign nail unit tumor of the distal nail matrix and nail bed that typically presents as solitary longitudinal erythronychia with distal subungual hyperkeratosis and focal onycholysis. Atypical OP is a newly recognized and evolving concept in dermatopathology. Herein, we present a histopathologically-proven atypical OP with a classic clinical appearance that developed during pregnancy. A 37-year-old Gravida two Para one woman presented with a red longitudinal band on the left thumbnail that appeared during the first trimester of an uncomplicated pregnancy. The lesion was asymptomatic; however, it was gradually increasing in size, prompting a longitudinal excisional biopsy of the lesion post-partum. Histopathologic evaluation of the nail unit revealed common features of an OP, including acanthosis and papillomatosis of the nail bed with focal matrix metaplasia. There were focal areas of cytologic atypia and mitotic figures with corresponding increased suprabasilar Ki-67 expression. The tumor was excised with Mohs micrographic surgery in one stage, and the resulting defect healed with secondary intention. No recurrence was observed at 6-month follow-up. This case expands the current literature on histopathologically-proven atypical OP and describes the novel occurrence during pregnancy.

BackgroundFutibatinib, a novel FGFR inhibitor, is a promising therapy for cancers with FGFR alterations. However, its safety profile remains under investigation. This study evaluates futibatinib-associated adverse events using the FDA Adverse Event Reporting System (FAERS).MethodsA retrospective pharmacovigilance analysis was conducted using FAERS data from January 1, 2013, to March 9, 2025. Disproportionality analysis was performed via OpenVigil 2.1, with signals defined by a reporting odds ratio (ROR) > 2.00 and a 95% confidence interval lower bound >1.00. Events with at least two reports were included after deduplication and standardization.ResultsStrong safety signals were identified. Hyperphosphatasemia showed the highest association (ROR 1612.73; 6 events), followed by elevated blood phosphorus (ROR 603.85; 3 events). Dermatologic toxicities, including onycholysis (ROR 520.15) and onychoclasis (ROR 126.20), were also notable.ConclusionThese findings highlight the range of adverse events associated with this agent. These events may reflect direct drug effects and individual variability. Further studies are needed to clarify mechanisms and inform clinical management.