Review

Authors: Nilesh Kodali, Viral M Patel, Robert A Schwartz...

Keratosis pilaris (KP) is a common, hyperkeratotic skin condition characterized by small, folliculocentric papules with variable perifollicular erythema. We provide an updated review on the pathogenesis, clinical manifestations, and management of this common, and often annoying, finding. KP represents a family of follicular disorders, of which KP simplex is by far the most common. Other variants and rare subtypes include keratosis pilaris rubra, erythromelanosis follicularis faciei et colli, and the spectrum of keratosis pilaris atrophicans. Inherited mutations of the FLG gene and ABCA12 gene have been implicated etiologically. KP may be associated with ichthyosis vulgaris and palmar hyperlinearity, but less likely atopic dermatitis. Some potential differential diagnoses for KP include lichen spinulosus, phrynoderma, ichthyosis vulgaris, and trichostasis spinulosa. General cutaneous measures such as hydrating skin, avoiding long baths or showers, and using mild soaps or cleansers should be recommended. Topical keratolytic agents are first-line therapy, followed by topical retinoids and corticosteroids. Recent options include a variety of lasers and microdermabrasion if the patient is refractory to topical therapy.

Topics: Abnormalities, Multiple; Humans; Skin; Darier Disease; Ichthyosis Vulgaris; Eyebrows

PubMed: 37166753
DOI: 10.23736/S2784-8671.23.07594-1

Review

Authors: Susan Müller

White lesions of the oral cavity are quite common and can have a variety of etiologies, both benign and malignant. Although the vast majority of publications focus on leukoplakia and other potentially malignant lesions, most oral lesions that appear white are benign. This review will focus exclusively on reactive white oral lesions. Included in the discussion are frictional keratoses, irritant contact stomatitis, and smokeless tobacco keratoses. Leukoedema and hereditary genodermatoses that may enter in the clinical differential diagnoses of frictional keratoses including white sponge nevus and hereditary benign intraepithelial dyskeratosis will be reviewed. Many products can result in contact stomatitis. Dentrifice-related stomatitis, contact reactions to amalgam and cinnamon can cause keratotic lesions. Each of these lesions have microscopic findings that can assist in patient management.

Topics: Humans; Keratosis; Mouth Diseases; Mouth Mucosa; Tobacco, Smokeless

PubMed: 30671762
DOI: 10.1007/s12105-018-0986-3

Authors: Dan-Dan Zou, Ya-Zhou Sun, Xin-Jie Li...

Cutaneous squamous cell carcinoma (cSCC) is the second most frequent of the keratinocyte-derived malignancies with actinic keratosis (AK) as a precancerous lesion. To comprehensively delineate the underlying mechanisms for the whole progression from normal skin to AK to invasive cSCC, we performed single-cell RNA sequencing (scRNA-seq) to acquire the transcriptomes of 138,982 cells from 13 samples of six patients including AK, squamous cell carcinoma in situ (SCCIS), cSCC, and their matched normal tissues, covering comprehensive clinical courses of cSCC. We identified diverse cell types, including important subtypes with different gene expression profiles and functions in major keratinocytes. In SCCIS, we discovered the malignant subtypes of basal cells with differential proliferative and migration potential. Differentially expressed genes (DEGs) analysis screened out multiple key driver genes including transcription factors along AK to cSCC progression. Immunohistochemistry (IHC)/immunofluorescence (IF) experiments and single-cell ATAC sequencing (scATAC-seq) data verified the expression changes of these genes. The functional experiments confirmed the important roles of these genes in regulating cell proliferation, apoptosis, migration, and invasion in cSCC tumor. Furthermore, we comprehensively described the tumor microenvironment (TME) landscape and potential keratinocyte-TME crosstalk in cSCC providing theoretical basis for immunotherapy. Together, our findings provide a valuable resource for deciphering the progression from AK to cSCC and identifying potential targets for anticancer treatment of cSCC.

Topics: Humans; Carcinoma, Squamous Cell; Keratosis, Actinic; Skin Neoplasms; Keratinocytes; Transcriptome; Tumor Microenvironment

PubMed: 38099574
DOI: 10.7554/eLife.85270

Review

Authors: Thomas Dirschka, Girish Gupta, Giuseppe Micali...

Actinic keratosis (AK) is a chronic skin disease in which multiple clinical and subclinical lesions co-exist across large areas of sun-exposed skin, resulting in field cancerisation. Lesions require treatment because of their potential to transform into invasive squamous cell carcinoma. This article aims to provide office-based dermatologists and general practitioners with simple guidance on AK treatment in daily clinical practice to supplement existing evidence-based guidelines. Novel aspects of the proposed treatment algorithm include differentiating patients according to whether they have isolated scattered lesions, lesions clustered in small areas or large affected fields without reference to specific absolute numbers of lesions. Recognising that complete lesion clearance is rarely achieved in real-life practice and that AK is a chronic disease, the suggested treatment goals are to reduce the number of lesions, to achieve long-term disease control and to prevent disease progression to invasive squamous cell carcinoma. In the clinical setting, physicians should select AK treatments based on local availability, and the presentation and needs of their patients. The proposed AK treatment algorithm is easy-to-use and has high practical relevance for real-life, office-based dermatology.

Topics: Algorithms; Aminoquinolines; Antineoplastic Agents; Combined Modality Therapy; Cryotherapy; Disease Progression; Humans; Imiquimod; Keratosis, Actinic; Laser Therapy

PubMed: 27796187
DOI: 10.1080/09546634.2016.1254328

Review

Authors: Clarissa Prieto Herman Reinehr, Renato Marchiori Bakos

Actinic keratoses are dysplastic proliferations of keratinocytes with potential for malignant transformation. Clinically, actinic keratoses present as macules, papules, or hyperkeratotic plaques with an erythematous background that occur on photoexposed areas. At initial stages, they may be better identified by palpation rather than by visual inspection. They may also be pigmented and show variable degrees of infiltration; when multiple they then constitute the so-called field cancerization. Their prevalence ranges from 11% to 60% in Caucasian individuals above 40 years. Ultraviolet radiation is the main factor involved in pathogenesis, but individual factors also play a role in the predisposing to lesions appearance. Diagnosis of lesions is based on clinical and dermoscopic examination, but in some situations histopathological analysis may be necessary. The risk of transformation into squamous cell carcinoma is the major concern regarding actinic keratoses. Therapeutic modalities for actinic keratoses include topical medications, and ablative and surgical methods; the best treatment option should always be individualized according to the patient.

Topics: Carcinoma, Squamous Cell; Dermoscopy; Humans; Keratosis, Actinic; Risk Factors; Severity of Illness Index; Skin Neoplasms

PubMed: 31789244
DOI: 10.1016/j.abd.2019.10.004

Authors: Nicole Natarelli, Amanda Krenitsky, Kerry Hennessy...

Seborrheic keratoses (SKs) are benign epidermal neoplasms presenting as waxy, brown to black papules and plaques. Patients often seek removal for cosmetic reasons or irritation. The objective of this systematic review is to assess the efficacy and safety of topical treatments for SKs. Studies involving any topical medication indicated for SK removal were retrieved from Embase, Scopus, PubMed, and Cochrane. The final search was conducted on November 9, 2021, and 26 reports met inclusion criteria. A quality rating scheme was utilized to assess evidence quality. Heterogeneity of treatments and outcome measures precluded meta-analysis. Topical treatments that yielded a good-to-excellent response include hydrogen peroxide, Maxacalcitol 25 µg/g, BID Tazarotene 0.1% cream, 5% potassium dobesilate cream, 1% diclofenac sodium solution, urea-based solution, and 65% and 80% trichloroacetic acid. Local skin reactions were often mild and transient. Topical hydrogen peroxide showed the greatest evidence for clinical clearance of SKs, although there are no studies to our knowledge that directly compared hydrogen peroxide to current first-line treatments (e.g. cryotherapy or shave excision). The results of this review suggest viable and safe treatment of SK with topical therapies; however, there remains demand for topical treatments that reliably equate or exceed the efficacy of current first-line therapies.Key Points Are safe and efficacious topical treatments for seborrheic keratoses available? Topical treatments for seborrheic keratoses yield different responses and may be associated with local skin reactions. Topical hydrogen peroxide shows the greatest evidence for clinical clearance of seborrheic keratoses and may be a viable option for patients requesting noninvasive removal. No studies to our knowledge directly compare hydrogen peroxide to current first-line treatments. There remains demand for topical treatments that reliably equate or exceed the efficacy of current first-line therapies.

Topics: Humans; Administration, Topical; Cryotherapy; Hydrogen Peroxide; Keratosis, Seborrheic; Treatment Outcome

PubMed: 36215682
DOI: 10.1080/09546634.2022.2133532

European consensus-based interdisciplinary guideline for diagnosis, treatment and prevention of actinic keratoses, epithelial UV-induced dysplasia and field cancerization on behalf of European Association of Dermato-Oncology, European Dermatology Forum, European Academy of Dermatology and...

Authors: Lidija Kandolf, Ketty Peris, Josep Malvehy...

A collaboration of multidisciplinary experts from the European Association of Dermato-Oncology, the European Dermatology Forum, the European Academy of Dermatology and Venereology, and the European Union of Medical Specialists was formed to develop European recommendations on AK diagnosis and treatment, based on current literature and expert consensus. This guideline addresses the epidemiology, diagnostics, risk stratification and treatments in immunocompetent as well as immunosuppressed patients. Actinic keratoses (AK) are potential precursors of cutaneous squamous cell carcinoma (cSCC) and display typical histopathologic and immunohistochemical features of this malignancy in an early stage. They can develop into cSSC in situ and become invasive in a low percentage of cases. AK is the most frequent neoplasia in white populations, frequently occurring within a cancerous field induced by ultraviolet radiation. Since it cannot be predicted, which lesion will progress to cSCC and when treatment is usually recommended. The diagnosis of AK and field cancerization is made by clinical examination. Dermatoscopy, confocal microscopy, optical coherence tomography or line-field confocal-OCT can help in the differential diagnosis of AK and other skin neoplasms. A biopsy is indicated in clinically and/or dermatoscopically suspicious and/or treatment-refractory lesions. The choice of treatment depends on patients' and lesion characteristics. For single non-hyperkeratotic lesions, the treatment can be started upon patient's request with destructive treatments or topical treatments. For multiple lesions, field cancerization treatment is advised with topical treatments and photodynamic therapy. Preventive measures such as sun protection, self-examination and repeated field cancerization treatments of previously affected skin areas in high-risk patients are advised.

Topics: Humans; Keratosis, Actinic; Skin Neoplasms; Carcinoma, Squamous Cell; Ultraviolet Rays; Europe; Consensus; Dermatology

PubMed: 38451047
DOI: 10.1111/jdv.19897

Review

Authors: Dóra Plázár, Marie Isolde Joura, Norbert Kiss...

Genodermatoses are a group of inherited skin diseases whose diagnosis is challenging due to their rarity as well as their clinical and genetic diversity. The majority of genodermatoses are autosomal or X‑linked inherited, but mosaic forms are also observed. Genodermatoses comprise various phenotypes ranging from limited cutaneous disease to severe cutaneous and extracutaneous involvement and may also be early warning signs of a multisystemic disorder. Despite recent advances in genetic technology and skin imaging modalities, dermoscopy can be useful for screening, diagnosis, and treatment follow-up. In ectopic mineralization and lysosomal storage disorders (pseudoxanthoma elasticum and Fabry disease, respectively), cutaneous manifestations may indicate involvement of other organs. In keratinization diseases (e.g., ichthyoses) and acantholytic skin fragility disorders (e.g., Darier and Hailey-Hailey disease), dermoscopy may help to assess treatment response by visualizing background erythema, hyperkeratosis, and interkeratinocyte space prominence. Dermoscopy is a noninvasive, easily accessible, useful, in vivo assessment tool that is well established in dermatology to recognize characteristic features of genodermatoses.

Topics: Humans; Dermoscopy; Skin; Ichthyosis; Keratosis; Pemphigus, Benign Familial

PubMed: 36882583
DOI: 10.1007/s00105-023-05124-7

Authors: Curtis J Petruzzelli, Alison Varano, Andrew Desrosiers...

Smokeless tobacco keratosis is a benign lesion characterized by the formation of white, gray, or pale macules or papules with wrinkling or rugae. It forms in the oral mucosa in response to the use of smokeless tobacco products. We present a 50-year-old man with an extensive history of smokeless tobacco use and development of the characteristic lesion. Shave biopsy showed typical changes of this benign condition and tobacco cessation was recommended.

Topics: Male; Humans; Middle Aged; Tobacco, Smokeless; Keratosis; Biopsy; Mouth Mucosa

PubMed: 37591270
DOI: 10.5070/D329361430

Authors: Hiroki Matsuura, Akemi Senoo, Mari Saito...

Topics: Administration, Oral; Administration, Topical; Aged; Animals; Antiparasitic Agents; Bedridden Persons; Diagnosis, Differential; Humans; Ivermectin; Keratosis; Male; Sarcoptes scabiei; Scabies; Skin; Treatment Outcome

PubMed: 30849040
DOI: 10.3949/ccjm.86a.18081