Proliferating inverted follicular keratosis of genital skin: Case series of a challenging variant.

BACKGROUND: Inverted follicular keratosis (IFK) is a benign cutaneous epithelial tumor typically presenting as a small papule on the head and neck. We have encountered deep endophytic tumors on genital skin with some characteristics of IFK but also atypical features, raising concern for squamous cell carcinoma (SCC). METHODS: Four such tumors were identified in our database. Histopathologic analysis and ancillary studies were performed. RESULTS: All patients were young women who presented with a solitary 0.5-1.0 cm lesion on the vulva, perineum, or inner buttock. Each showed a squamous proliferation arising from the epidermis, with endophytic growth that was deep and bulbous but not infiltrative. The tumor lobules contained eosinophilic keratinocytes, forming numerous squamous eddies. Small irregular spaces and dyskeratotic cells were frequently found. Nuclear pleomorphism was minimal to absent. All demonstrated wild-type p53 expression and lack of p16 block positivity. In situ hybridizations for human papillomavirus were negative. None of the three cases with follow-up data showed evidence of recurrence. CONCLUSIONS: The absence of infiltrative growth or significant pleomorphism, the presence of numerous squamous eddies, the reassuring immunoprofile, and the lack of evidence of recurrence support a variant of IFK and speak against SCC. We propose the term "proliferating IFK" to highlight the florid squamous proliferation. Recognition of this unusual variant would avoid overdiagnosis of SCC.

Milia en plaque on the shoulder as an early manifestations of mycosis fungoides.

Milia en plaque (MEP) is an uncommon skin condition identified as retroauricular confluent milium by Boulzer and Fouqet in 1903 [1]. It can be mistaken for other dermatoses like Favre-Racouchot nodular elastosis, steatocystoma multiplex, and nevus comedonicus. Milia en plaque can either be primary or secondary and is typically benign, often triggered by dermatological procedures like cryotherapy, as reported in this journal. In some cases, MEP can arise as a secondary manifestation of other diseases, including folliculotropic mycosis fungoides (FMF). Despite this association, there are few documented cases in the literature. Herein, we present a patient in whom MEP served as the initial clinical presentation of FMF; the treatment involved oral retinoids and phototherapy. Furthermore, we highlight distinctive features of both conditions. It is important to emphasize that early diagnosis and treatment of FMF are vital for the patient's quality of life. The presence of MEP can serve as a valuable indicator for identifying it.

Smokeless tobacco keratosis in oral mucosa with epithelial dysplasia: A case report.

RATIONALE: Smokeless tobacco use is a risk factor for the development of various oral lesions, among which is smokeless tobacco keratosis (STK). This condition is caused by constant frictional irritation of smokeless tobacco products against the oral mucosa and appears as a White-to-gray plaque with wrinkling. PATIENT CONCERNS: A 50-year-old man who had been using smokeless tobacco for 24 years visited our clinic complaining of changes in the lower right sulcus of the oral cavity for 10 days. Clinical examination revealed a unilateral, nonhomogeneous White lesion in the area of the complaint. Histopathological examination showed hyperkeratosis, areas of keratin plugging, and mild dysplastic epithelial changes. DIAGNOSIS: The clinico-histopathological correlation suggested a diagnosis of STK with focal mild epithelial dysplasia. INTERVENTION AND OUTCOME: A comprehensive management plan included maintaining oral hygiene, education on the detrimental effects of smokeless tobacco, advice to cease smoking, and regular follow-up to monitor the potential for malignant transformation. The patient was referred to a tobacco cessation society for tailored advice and counseling. On follow-up visits, there was an improvement in the lesion after habitual cessation. LESSONS: The diagnosis of tobacco-related oral lesions is often delayed, which may result in malignant transformation. This illustrates the need to train healthcare professionals to identify tobacco-related conditions at an early stage and to educate patients regarding the harmful effects of tobacco use.

Treatment of Keratosis Lichenoides Chronica With Upadacitinib.

This case report describes a 30-year-old man presenting with 1-year history of nonitchy red papules and patches who was subsequently treated with upadacitinib.

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.

Evaluation of linear dermatoses by reflectance confocal microscopy in children.

Lichen striatus (LS), linear psoriasis (LPs), linear cutaneous lupus erythematosus (LCLE) and linear lichen planus (LLP) often have similar clinical manifestations, which makes clinical diagnosis with the naked eye difficult; therefore, they are easily misdiagnosed. The purpose of this study was to determine whether reflectance confocal microscopy (RCM) is helpful in differentiating between these four linear dermatoses in children. This retrospective study included 14 patients with LS, nine with LPs, eight with LCLE and 12 with LLP. All patients were analysed using RCM, and biopsies were collected from lesions previously imaged by RCM. For LS, the dermal papillary rings were partially absent, but when present, manifested with small, homogeneously round, bright cells and occasionally highly refractive plump cellular structures, aggregated in clusters. LPs exhibited dark cyst-like structures with small, bright, round cells aggregated at the epidermal level; at the dermal-epidermal junction, homogeneously distributed, enlarged, faint dermal papillary rings and numerous enlarged low-refractive canalicular structures were observed in the superficial dermis. LCLE and LLP exhibited similar manifestations, including epidermal disarray, almost total absence of dermal papillary rings, and various sized refractive structures densely distributed in the dermis. The key distinguishing features of LCLE were the different sized structures mainly clustered around hair follicles, while LLP demonstrated dense structures with a scattered distribution. RCM may be used to distinguish between the key features of LS, LPs, LCLE and LLP in children.

[A man with limescale splashes]. / Een man met kalkspatten.

A 79-year-old man visits his general practitioner due to white spots on his hands and feet. Upon examination, numerous white papules are observed, leading to a diagnosis of stucco keratosis. Stucco keratosis is typically asymptomatic and is identified by benign keratotic papules. Treatment is challenging because of the large quantities.

Diseases categorized as autoinflammatory keratinization diseases (AiKDs), and their pathologies and treatments.

Whole-exome and whole-genome sequencing have become widespread in approximately the last 15 years, and the predisposing factors and pathomechanisms of inflammatory keratinization diseases, which have been unknown for a long time, have gradually been revealed. Hence, various inflammatory keratinization diseases are recognized to cause innate immunity hyperactivation. Therefore, we have been advocating for the clinical entity, "autoinflammatory keratinization diseases (AiKDs)" since 2017. AiKDs are inflammatory keratinization diseases caused by autoinflammatory-related pathomechanisms in the skin. The aberrant activation of innate immunity and the resultant autoinflammation in the epidermis and the superficial dermis in AiKDs cause hyperkeratosis in the epidermis. Our initially proposed concept of AiKDs included generalized pustular psoriasis and related conditions, pityriasis rubra pilaris type V, and familial keratosis lichenoides chronica. Since then, the number of diseases known to be AiKDs has increased as previously unknown disease-causing factors and pathogenetic mechanisms of inflammatory keratinization diseases have been clarified one by one. To date, porokeratosis, hidradenitis suppurative, keratosis linearis with ichthyosis congenita and sclerosing keratoderma (KLICK) syndrome, and AiKDs associated with epidermal growth factor receptor (EGFR) deficiency or with hepatitis and autism have been recognized as AiKDs. The concept of AiKDs is considered extremely useful in our precise understanding of the pathogeneses behind inflammatory keratinization diseases and our appropriate treatment method selection. The number of AiKDs is expected to grow with the clarification of the pathomechanisms of further inflammatory keratinization diseases.

Hematoporphyrin injection mediated photodynamic therapy for secondary squamous cell carcinoma of arsenical keratosis: A case report.

Hematoporphyrin injection (HpD) mediated photodynamic therapy (PDT) has demonstrated efficacy in treating various types of Bowen's disease, including basal-cell carcinoma, squamous cell carcinoma, extramammary Paget's disease, and actinic keratosis. We present a case of a male patient who developed squamous cell carcinoma as a result of repeated instances of arsenic-induced keratosis on both his hands and feet. Due to the involvement of the joint in both hands, the patient declined the conventional surgical resection treatment since it could potentially impact normal physiological function. Instead, the patient chose to undergo hemoporphyrin photodynamic therapy. After the treatment, the rash was entirely eliminated and there were no restrictions in the movement of the joint. Nevertheless, a local recurrence was detected throughout the two-year monitoring period. Arsenical keratosis carries a substantial likelihood of recurring. However, we believe that hemoporphyrin photodynamic therapy is effective in treating this condition.

New keratose sponges after the end-Permian extinction provide insights into biotic recoveries.

We challenge the prevailing view that the end-Permian extinction impeded the Triassic evolution of sponges. Here, we report a deep-water community dominated by abundant keratose sponges in the lowest Triassic strata from Southwest China. The sponge fossils occur as dark elliptical imprints in mudstone with distinct oscula on their tops. The structure of preserved fibers suggests closest affinity with the extant Dictyoceratida, an aspiculate demosponge. The exceptional preservation plays a crucial role in retaining their exquisite structures. Sedimentary, taphonomic, pyrite framboid, and trace elemental analyses indicate that the sponges proliferated in an oxygen-poor habitat, demonstrating the high tolerance of sponges to severe conditions. Sponge proliferation is a signal of environmental upheaval but they also stabilized the ecosystem, driving the first phase of biotic recovery after the end-Permian extinction.

Infantile anogenital digitate keratoses.

Infantile anogenital digitate keratoses (IADK) represent a distinct and under-recognized pediatric condition of the perianal area of infants, significantly more frequent in males than females. The average age of onset is 3.2 months, and it is self-remitting by 2 years of age. Perianal spiny keratoses resistant to usual topical therapies are the hallmark of IADK. We present a series of three cases of IADK seen at the dermatology clinic of the CHU Sainte-Justine to raise awareness on this pediatric condition, and to prevent invasive workup.

[An adult woman with a linear skin eruption]. / Een vrouw met een streepvormige huidafwijking.

A 43-year-old woman presented with a linear skin eruption following the Blaschko lines on the left flank. Histopathological examination revealed lichenoid inflammation and a perieccrine lymphocytic infiltrate. Based on these clinical and histopathological findings the diagnosis lichen striatus was made.

Strengthening the relationship between intractable plantar keratosis and human papillomavirus.

The aim of the study was to determine the presence of human papillomavirus (HPV) in patients with intractable plantar keratosis (IPK) by comparing the histopathological findings of biopsies. A prospective, observational, and concordance study was carried out. Three different specimens were taken from each IPK. A first punch was sent for histopathological examination, and a second punch and a superficial skin scraping were both sent for HPV  polymerase chain reaction (PCR) and type determination. A total of 51 patients were included. From the histopathological examination, it was determined that 35 (68.6%) samples were diagnosed as warts and 16 (31.3%) as keratosis. However, the presence of HPV was confirmed by PCR in 49 (96.1%) and in 42 (82.4%) samples obtained by punch and superficial scraping, respectively. In the 49 PCR-positive samples, the most common HPV types were HPV1, HPV2, HPV27, HPV57, and HPV65, accounting for 81.6% of the samples. In conclusion, this study demonstrates that HPV infection and IPK lesions are very closely related. Although we cannot confirm that HPV is the cause of the development of IPK, the high prevalence of HPV observed in these lesions calls for a change to the procedures for managing IPK.

Morphea as an isotopic response to pigmented purpuric dermatosis and lichen striatus.

Morphea is an uncommon inflammatory and fibrosing disorder that has a polymorphous clinical presentation. We report two cases of morphea developing as an isotopic response after a preceding benign skin disease, accompanied by a review of the literature. This case series highlights the importance of return to care recommendations for benign skin conditions such lichen striatus and pigmented purpuric dermatoses due to the rare possibility of subsequent morphea development.