Hyperkeratosis Of Nails Research Articles

Multiple Onychopapillomas and BAP1 Tumor Predisposition Syndrome

BRCA1-associated protein (BAP1) tumor predisposition syndrome (TPDS) is a cancer genodermatosis associated with high risk of uveal and cutaneous melanoma, basal cell carcinoma, and multiple internal malignant neoplasms, including mesothelioma and renal cell carcinoma. Early detection of the syndrome is important for cancer surveillance and genetic counseling of family members who are at risk. To determine the prevalence of nail abnormalities in individuals with pathogenic germline variants in BAP1. In this prospective cohort study, individuals who were known carriers of pathogenic BAP1 germline variants were consecutively enrolled between October 10, 2023, and March 15, 2024. Dermatologic evaluation for nail abnormalities was performed, including a history of nail abnormalities and associated symptoms, physical examination, medical photography, and nail biopsy for histopathology. This was a single-center study conducted at the National Institutes of Health Clinical Center. Primary outcomes were the prevalence and spectrum of nail changes and histopathologic characterization. Among 47 participants (30 female [63.8%]; mean [SD] age, 46.4 [15.1] years) ranging in age from 13 to 72 years from 35 families, nail abnormalities were detected in 41 patients (87.2%) and included leukonychia, splinter hemorrhage, onychoschizia, and distal nail hyperkeratosis. Clinical findings consistent with onychopapilloma were detected in 39 patients (83.0%), including 35 of 40 individuals aged 30 years or older (87.5%). Nail bed biopsy was performed in 5 patients and was consistent with onychopapilloma. Polydactylous involvement with onychopapillomas was detected in nearly all patients who had nail involvement (38 of 39 patients [97.4%]). This study found that BAP1 TPDS was associated with a high rate of nail abnormalities consistent with onychopapillomas in adult carriers of the disease. Findings suggest that this novel cutaneous sign may facilitate detection of the syndrome in family members who are at risk and patients with cancers associated with BAP1 given that multiple onychopapillomas are uncommon in the general population and may be a distinct clue to the presence of a pathogenic germline variant in the BAP1 gene.

A Case Study of Pachyonychia Congenita in Bangladesh

In 1906 Jadassohn and Lewandowsky described a rare genodermatoses and named it pachyonychia congenita. Pachy means thick. It is a group of genodermatoses involving keratin mutation with thickened nails and variable associated findings. Pachyonychia congenita is a rare disease having four types. However, type 1 and type 2 can be considered common among them. It can often mimic with fungal infection as nail hyperkeratosis can occur in both.

Psoriatic Inflammation Facilitates the Onset of Arthritis in a Mouse Model

Psoriatic arthritis (PsA) is a seronegative, inflammatory joint disease associated with psoriasis. In most patients with PsA, skin lesions precede arthritis; however, the causality of skin inflammation for the development of arthritis remains unclear. Gp130F759/F759 knock-in (F759) mice develop autoimmune arthritis after 1 year of age through persistent signal transducer and activator of transcription 3 (Stat3) activation due to impairment in SOCS3-dependent negative regulation. Here, we crossed F759 mice with K5.Stat3C transgenic mice, in which keratinocytes express constitutive active Stat3 (Stat3C), leading to generation of psoriasis-like skin change. F759 mice harboring the K5.Stat3C transgene not only had aggravated skin lesions but also spontaneously developed arthritis with high penetrance in adjacent paws as early as 3 weeks of age. The joint lesions included swelling of the peripheral paws and nail deformities contiguous with the skin lesions, closely resembling PsA. Histopathologic study revealed enthesitis and bone erosions, with mononuclear cell infiltrates. Quantitative reverse transcriptase-PCR (RT-PCR), immunohistochemical analyses, and flow cytometry showed upregulation of the IL-23/T helper type 17 (Th17) pathway in affected joints. Furthermore, enforced generation of psoriasis-like skin inflammation by topical treatment with 12-O-tetradecanoylphorbol-13-acetate (TPA) in F759 mice induced swelling of the underlying joints. This animal model renders psoriatic inflammation as the driver of arthritis and helps to further understand the pathogenesis of PsA.

Sarcoid and the nail: review of the literature

Nail involvement in sarcoidosis is rare, but its presence is often associated with chronic systemic disease. We have reviewed all 33 reported cases of nail involvement with sarcoidosis, including our own case. Nail changes in sarcoidosis, while rare, can include dystrophy (n=10, 30%), onycholysis (n=7, 21%), subungual hyperkeratosis (n=7, 21%), nail hyperkeratosis (n=2, 6%) and longitudinal ridging (n=8, 24%). All reported cases of nail sarcoidosis occurred in the setting of systemic involvement. In almost half of the cases, bony cysts were noted on radiological examination. The presence of nail dystrophy in a patient with sarcoidosis should therefore prompt radiological examination and investigation for systemic involvement.

Josef Jadassohn (1863–1936), Felix Lewandowsky (1879–1921), and their syndrome

Josef Jadassohn (1863–1936) and his assistant, Felix Lewandowsky (1879–1921), were eminent German dermatologists who had several dermatology conditions linked eponymously. One such condition is Jadassohn–Lewandowsky syndrome, which is a type of pachyonychia congenita – a disease that is characterized by severe thickening of the nail due to massive nail hyperkeratosis. This report describes Jadassohn–Lewandowsky syndrome and the men behind this disease.

Palmoplantar nonpustular psoriasiform dermatitis in a rhesus macaque

A case of psoriasiform dermatitis in an adult male rhesus macaque is reported. Appearing spontaneously, the condition presented the clinical and histopathological features of human palmoplantar nonpustular psoriasis. The animal developed multiple scaly plaques on his palms and soles, as well as nail hyperkeratosis and widening of the nail root. Microscopically, the skin lesions showed epidermal hyperkeratosis with multifocal parakeratosis, neutrophil microabscesses in the stratum corneum, a loss of granule cell layer under the microabscesses, acanthosis, and elongation of the rete ridges; the superficial dermis showed a dense inflammatory infiltrate containing lymphocytes, macrophages and neutrophils, as well as dilated and tortuous blood vessels. The lesions improved for 15 days after intramuscular corticosteroid depot therapy and worsened slightly afterwards. Later, a spontaneous, progressive remission coincided with the beginning of spring and lasted until the end of summer; the skin lesions practically disappeared during this period, and the nails looked nearly normal. During the next autumn and winter only nail hyperkeratosis was present. Serum analyses showed hyperproteinaemia and hyperglobulinaemia during the outbreak phase and normal values during remission. The clinical and histopathological features of this case, as well as its evolution, are compared with the three other reported cases of psoriasiform skin lesions in nonhuman primates. To the authors' knowledge, this is the first report of a definite palmoplantar nonpustular psoriasiform dermatitis in a rhesus macaque.