Atopic dermatitis (AD) and food allergy (FA) share similar type 2 inflammation and commonly co‐occur, but the precise proportion of AD patients with FA and vice versa, as well as the effect of AD disease severity on the strength of this association remains uncertain. The aim of this comprehensive systematic review and meta‐analysis was to determine the prevalence and bidirectional associations of AD with food sensitivity (FS), FA and challenge‐proven food allergy (CPFA). We searched PubMed and EMBASE and three independent reviewers performed title/abstract and full‐text review and data extraction. Overall, 557 articles (n = 225,568 individuals with AD, n = 1,128,322 reference individuals; n = 1,357,793 individuals with FS, FA or CPFA, n = 1,244,596 reference individuals) were included in quantitative analyses. The overall pooled prevalence of FS, FA and CPFA in individuals with AD were 48.4% (95% confidence interval: 43.7–53.2), 32.7% (28.8–36.6) and 40.7% (34.1–47.5) respectively. AD prevalence among individuals with FS, FA and CPFA were 51.2% (46.3–56.2), 45.3% (41.4–49.3) and 54.9% (47.0–62.8) respectively. Children with AD had higher pooled FS (49.8% (44.4–55.1)) and FA (31.4% (26.9–36.1)) prevalences than adults with AD (28.6% (13.4–46.8) and 24.1% (12.1–38.7) respectively). Prevalences of FS and FA numerically increased with AD severity. FS, FA and CPFA are common comorbidities of AD and are closely related. Physicians should be attentive to this relationship to optimize management and treatment strategies in patients.

Background: Psoriasis is a common chronic inflammatory skin disease with an exceptionally high burden for women. Objective: Sex-dependent differences in disease manifestation, severity, treatment choices, subjective disease perception, and the impact on quality of life and risk factors are described and comprehensively discussed. Methods: A literature search was conducted using MEDLINE (PubMed) and the Cochrane Library for systematic reviews to investigate the challenges in treating women with psoriasis. Results and conclusions: The incidence, prevalence, and manifestation of psoriasis of the skin are similar between different sexes. Genetic and environmental factors such as obesity and metabolic syndrome are risk factors and are not equally relevant or pronounced in women and men. Overall, women have a lower disease severity measured by the Psoriasis Area Severity Index, which is associated with a higher impairment of their life quality measured by the Dermatology Life Quality Index compared with men. In addition, women with psoriasis are more likely to have depression than men. Hormonal factors affect psoriasis, with a correlation of high estrogen levels and improvement of psoriasis. Data regarding differences in prescribing patterns of systemic treatments and the severity of psoriasis are not entirely consistent. Registry studies show that men tend to have more severe psoriasis and, in some cases, are prescribed systemic therapies more frequently. Women tend to respond better to systemic treatments and to experience more adverse events. Treatment options are the same for both sexes, except during pregnancy and lactation. Various treatment options are contraindicated due to fear of fetal or neonate harm and lack of data. Topical steroids can be prescribed with a high degree of safety during pregnancy. For other topical therapies (calcineurin inhibitors and vitamin D analogs), no studies of adverse effects in pregnancy are available, and safety data mainly stem from studies examining effects after systemic administration. Antitumor necrosis factor monoclonal antibodies (except for certolizumab pegol) have been associated with a possible increased risk of preterm birth, low gestational age, and cesarean deliveries. Prospective data on the safety of biologics other than antitumor necrosis factor-alpha antibodies to accurately assess whether novel biologics (eg, anti-interleukin 17, 12/23, 23) can be used for systemic therapy in pregnancy are lacking or currently being conducted.

Epidermal growth factor receptor (EGFR) and MEK inhibitors (EGFRi/MEKi) are beneficial for the treatment of solid cancers but are frequently associated with severe therapy-limiting acneiform skin toxicities. The underlying molecular mechanisms are poorly understood. Using gene expression profiling we identified IL-36γ and IL-8 as candidate drivers of EGFRi/MEKi skin toxicity. We provide molecular and translational evidence that EGFRi/MEKi in concert with the skin commensal bacterium Cutibacterium acnes act synergistically to induce IL-36γ in keratinocytes and subsequently IL-8, leading to cutaneous neutrophilia. IL-36γ expression was the combined result of C. acnes–induced NF-κB activation and EGFRi/MEKi–mediated expression of the transcription factor Krüppel-like factor 4 (KLF4), due to the presence of both NF-κB and KLF4 binding sites in the human IL-36γ gene promoter. EGFRi/MEKi increased KLF4 expression by blockade of the EGFR/MEK/ERK pathway. These results provide an insight into understanding the pathological mechanism of the acneiform skin toxicities induced by EGFRi/MEKi and identify IL-36γ and the transcription factor KLF4 as potential therapeutic targets.

The exponential increase in algorithm-based mobile health (mHealth) applications (apps) for melanoma screening is a reaction to a growing market. However, the performance of available apps remains to be investigated. In this prospective study, we investigated the diagnostic accuracy of a class 1 CE-certified smartphone app in melanoma risk stratification and its patient and dermatologist satisfaction. Pigmented skin lesions ≥ 3 mm and any suspicious smaller lesions were assessed by the smartphone app SkinVision^® (SkinVision^® B.V., Amsterdam, the Netherlands, App-Version 6.8.1), 2D FotoFinder ATBM^® master (FotoFinder ATBM^® Systems GmbH, Bad Birnbach, Germany, Version 3.3.1.0), 3D Vectra^® WB360 (Canfield Scientific, Parsippany, NJ, USA, Version 4.7.1) total body photography (TBP) devices, and dermatologists. The high-risk score of the smartphone app was compared with the two gold standards: histological diagnosis, or if not available, the combination of dermatologists’, 2D and 3D risk assessments. A total of 1204 lesions among 114 patients (mean age 59 years; 51% females (55 patients at high-risk for developing a melanoma, 59 melanoma patients)) were included. The smartphone app’s sensitivity, specificity, and area under the receiver operating characteristics (AUROC) varied between 41.3–83.3%, 60.0–82.9%, and 0.62–0.72% according to two study-defined reference standards. Additionally, all patients and dermatologists completed a newly created questionnaire for preference and trust of screening type. The smartphone app was rated as trustworthy by 36% (20/55) of patients at high-risk for melanoma, 49% (29/59) of melanoma patients, and 8.8% (10/114) of dermatologists. Most of the patients rated the 2D TBP imaging (93% (51/55) resp. 88% (52/59)) and the 3D TBP imaging (91% (50/55) resp. 90% (53/59)) as trustworthy. A skin cancer screening by combination of dermatologist and smartphone app was favored by only 1.8% (1/55) resp. 3.4% (2/59) of the patients; no patient preferred an assessment by a smartphone app alone. The diagnostic accuracy in clinical practice was not as reliable as previously advertised and the satisfaction with smartphone apps for melanoma risk stratification was scarce. MHealth apps might be a potential medium to increase awareness for melanoma screening in the lay population, but healthcare professionals and users should be alerted to the potential harm of over-detection and poor performance. In conclusion, we suggest further robust evidence-based evaluation before including market-approved apps in self-examination for public health benefits.

Cutaneous lichenoid drug eruptions (LDE) are adverse drug reactions (ADR) characterized by symmetric, erythematous, violaceous papules reminiscent but rarely fully characteristic of lichen planus (LP). We aimed to analyse the literature describing cases of LDE within the last 20 years to provide additional insight into culprit drugs, typical latency to onset of the eruption, the spectrum of clinical presentations, severity and management. A literature search was conducted in MEDLINE between January 2000 and 27 January 2021. The keywords ‘lichenoid drug rash’ and ‘lichenoid drug eruption’ were used. Cases were included if LDE diagnosis was made, and culprit drugs were identified. A total of 323 cases with LDE were identified from 163 published case reports and studies. The mean patient age was 58.5 years (1 month to 92 years), and 135 patients (41.8%) were female. Checkpoint inhibitors (CKI) were the most frequently reported culprit drugs (136 cases; 42.1%), followed by tyrosine kinase inhibitors (TKI) (39 cases; 12.0%) and anti‐TNF‐α‐monoclonal antibodies (13 cases; 4.0%). The latency between initiation of the drug and manifestation was 15.7 weeks (range: 0.1–208 weeks). After discontinuing the culprit drug, the median time to resolution was 14.2 weeks (range: 0.71–416 weeks). One hundred thirty‐six patients (42.1%) were treated with topical, and 54 patients (16.7%) with systemic glucocorticoids. Overall, we conclude that, albeit rare, LDE is challenging to diagnose ADR induced by mostly CKI, TKI, and biologics. Treatment modalities resemble that of lichen planus, and the culprit drugs had to be discontinued in only 26%, which is low compared with other types of adverse drug reactions. This is probably due to the low risk of aggravation (e.g. toxic epidermal necrolysis) if the drug is continued and the benefit/risk ratio favouring the drug, as is often the case in cancer therapy.