Actinic keratosis (AKs) is one of the most common skin lesions leading to an increased risk of developing squamous cell carcinoma and other skin malignancies. The lesions principally arise as a result of excessive ultraviolet (UV) exposure. AKs may regress spontaneously, remain stable or evolve to invasive squamous cell carcinoma. The risk of squamous cell carcinoma is significantly increased patients with more than 5 AKs. The main mechanisms involved in the formation of AK are inflammation, mutagenesis, oxidative stress, impaired apoptosis, immunosuppression, disregulation of cell growth and proliferation, and tissue remodeling. Human papilloma virus has also been correlated with the formation of some AKs. As an individual ages, his skin is exposed to increasing cumulative amounts of UV light and other environmental insults. This is especially true for the head, neck and forearms. These insults do not target only the skin where individual lesions develop, but also the surrounding area. In this area undetectable preclinical AK lesions or dysplastic cells may be present. The whole affected area is known as the 'field'. Therefore, management is divided into lesion-directed and field-directed therapies. Currently, the therapies in use are lesion-directed cryotherapy and/or excision, and field-directed topical agents: 5-fluorouracil, diclofenac, photodynamic therapy, imiquimod, and ingenol mebutate. Combining lesion-and field-directed therapies showed good results and several novel therapies are under investigation. Treatment is variable and personalized, what makes a gold standard management algorithm difficult to design. This review aims to describe the rationale behind the available treatment options for AKs based on current understanding of pathophysiology and epidemiology. (J Dermatol Case Rep. 2015; 9(2): 29-35)

Merkel cell carcinoma (MCC) is a rare but highly aggressive neuroendocrine skin cancer whose incidence has almost doubled in recent decades. Risk factors for MCC include age > 65 years, immunosuppression, sun exposure and infection by Merkel cell polyomavirus. MCC usually presents as rapidly growing, firm, red to violaceous nodule localized on the sun-exposed skin. Surgery followed by radiation therapy is considered to be the first-line treatment for primary or loco-regional MCC in order to prevent recurrences and lymph node metastasis, while chemotherapy has always been used to treat advanced forms. However, responses to chemotherapy are mostly of short duration, and the associated clinical benefit on overall survival is still unclear. The use of checkpoint inhibitors (CPIs) has shown good results in the treatment of advanced MCC and, consequently, CPIs are considered emerging immunotherapeutic options for these patients, although there are still no standardized treatments for patients with metastatic disease. Here we present a complete overview of the different possibilities for the treatment of MCC according to the stage of the disease, focusing on the emerging immunotherapies used for treating advanced MCC.

Importance: To date, no dermoscopic features have been described for the diagnosis of primary cutaneous B-cell lymphoma (PCBCL). This tool might be helpful for the clinical differential diagnosis in the context of single erythematous nodules of the skin. Observations: Ten cases of PCBCL, presenting clinically as solitary red/pinkish nodules, were retrospectively retrieved. Patient data were collected along with dermoscopic and histopathological features of each lesion. Most lesions (9/10) showed white circles with a salmon-colored background/area (6 lesions), scales (7 lesions), arborizing vessels (5 lesions) or a polymorphous vascular pattern (2 lesions). Histology revealed a cutaneous marginal zone lymphoma in 6 lesions, a follicle center lymphoma in 2 lesions and a diffuse large B-cell lymphoma in 2 lesions. Conclusions and Relevance: Dermoscopic examination may be helpful for improving the clinical recognition of PCBCL although skin biopsy remains mandatory.

Subcorneal pustular dermatosis (SCPD, also known as Sneddon-Wilkinson disease) is a rare, benign, chronic, sterile pustular eruption which usually develops in middle-age or elderly women; it is rarely seen in childhood and adolescence. The primary lesions are pea-sized pustules classically described as half-pustular, half-clear flaccid blisters. Histologically the most important feature is a subcorneal accumulation of neutrophils with the absence of spongiosis or acantholysis, although acantholysis may be reported in older lesions. In this paper we present the case of a 7-year-old boy diagnosed with SCPD based on the characteristic clinical and histological features. Dapsone has been successfully used in the treatment of the disease.

Melanoma is one of the most common cancers, with an increasing incidence worldwide. Disease stage represents the most important prognosis factor; therefore, early diagnosis is essential for melanoma patients' survival rates. Following the outbreak in China, the coronavirus disease 2019 (COVID-19) pandemic has spread all over the world and the majority of dermatological visits have been postponed. These measures could cause a delay in melanoma diagnosis and management leading to an increase of morbidity, mortality and healthcare costs. Herein we propose an alternative model of skin cancer screening and the organization of screening campaigns in order to detect malignant lesions early during this emergency period.

Hedgehog inhibitors are promising alternative treatments for patients with advanced basal cell carcinomas. Sonidegib (Odomzo Ò ), an oral smoothened (SMO) antagonist, is indicated for the treatment of adult patients with locally advanced basal cell carcinoma (laBCC) who present recurrence following surgery or radiation therapy, or those who are not candidates for surgery or radiotherapy. Several studies and randomized controlled trials have been conducted to evaluate the efficacy, safety, and tolerability of this new molecule that has demonstrated a good response rate (44%). Grade 1-2 adverse events have also been repor-ted. Further studies of real-world experiences are needed to better understand the correct management of the drug, alternative dosing regimens, and differences with other hedgehog inhibitors. This article provides a complete overview of the pharmacology and pharmacokinetics of sonidegib and a report of the trials and studies conducted. The most frequent adverse events and their correct management are also discussed.

Introduction: Non-melanoma skin cancer (NMSC) is the most common type of human tumor, with an estimated five million new cases each year. NMSC has been described as having a major impact on the health-related quality of life of the patient. Vismodegib is a hedgehog pathway inhibitor therapy for patients who are affected by locally advanced basal cell carcinoma (laBCC) and metastatic basal cell carcinoma and are ineligible for surgery and/or radiotherapy. The objective of this study was to assess treatment-emergent adverse events reported by patients with advanced BCC who were undergoing hedgehog pathway inhibitor therapy with vismodegib, and to quantify their health-related quality of life using the Dermatology Life Quality Index (DLQI) questionnaire.

Linked article: This article is commented on by N. Woltsche et al., pp. e144–e145 in this issue. To view this article visit https://doi.org/10.1111/jdv.15367.