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BackgroundDeep hypothermic circulatory arrest (DHCA) at

Self-inflicted skin disorders are artefact diseases inflicted by the use of multiple different means, for various different purposes. They account for about 2% of dermatology patient visits, and include disorders with a denied or hidden pathological behavior (factitious disorders) and disorders with a non-denied and nonhidden pathological behavior (compulsive disorders). In turn, factitious skin disorders are subdivided into 2 groups: factitious disorders without an external incentive (considered in a preceding work) and factitious disorders with external incentives. In the second eventuality, the simulator is motivated by illicit intent, wishing to evade civil duties or a prison sentence, for instance, or to exploit situations of an occupational nature, and is fully aware of his action and his intention. Apart of the two groups of pathomimic artefacts and malingering, some self-inflicted dermatoses are due to behavioral disorders involving compulsive habits (tics, psychological excoriations). The great majority of subjects suffering from the latter disturbances are quick to confess their urge to self-inflict lesions. The management, including both psychiatric and dermatological assessment, concludes this second part of the work regarding the self-inflicted cutaneous diseases.

Being able to perform surgery first-hand represents the backbone of every training program and the key to successful development of the new generation of skilful surgeons. In this issue of the Journal, Comanici et al. presented a thorough systematic summary of the current evidence on the outcomes of cardiothoracic operations performed by trainees.1 Taking for granted the importance of training young surgeons, it is paramount to identify and tackle any potential obstacles hindering the surgical growth of a trainee.

Risk stratification plays a major role in the clinical decision-making process, patient consent and clinical governance analysis. However, the calibration of current risk scores (e.g., European System for Cardiac Operative Risk Evaluation (EuroSCORE), The Society of Thoracic Surgeons (STS) risk score) has been shown to deteriorate over time – a process known as calibration drift. The introduction of new clinical scores with different variable sets typically result in disparate datasets due to different levels of missingness. This is a barrier to the full insight and predictive capability of datasets across all potentially available time ranges. Little is known about the use of ensemble learning with ensemble metrics to mitigate the effects of calibration drift and changing risk across siloed datasets and time. In this study, we evaluated the effect of various combinations of Machine Learning (ML) models in improving model performance. The National Adult Cardiac Surgery Audit dataset was used (January 1996 to March 2019, 647,726 patients). We trained six different base learner models including Logistic Regression, Neuronetwork, Random Forest (RF), Weighted Support Vector Machine, Xgboost and Bayesian Update, based on two different variable sets of either Logistic EuroScore (LogES) or EuroScore II (ES II), partitioned by the time of score adoption (1996–2011 and 2012–2019). These base learner models are ensembled using nine different combinations to produce homogeneous or heterogeneous ensembles. Discrimination, calibration, clinical effectiveness and overall accuracy were assessed using an ensemble metric, referred to as clinical effectiveness metric (CEM). Xgboost homogenous ensemble (HE) was the highest performing model (CEM 0.725) with AUC (0.8327; 95% Confidence Interval (CI) 0.8323–0.8329) followed by Random Forest HE (CEM 0.723; AUC 0.8325; 95%CI 0.8320–0.8326). Across different heterogenous ensembles, significantly better performance was obtained by combining siloed datasets across time (CEM 0.720) than building ensembles of either 1996–2011 (t-test adjusted, p = 1.67e-6) or 2012–2019 (t-test adjusted, p = 1.35e-193) datasets alone. Both homogenous and heterogenous ML ensembles performed significantly better than traditional recalibration method (Bayesian Update). Combining the metrics covering all four aspects of discrimination, calibration, clinical usefulness and overall accuracy into a single ensemble metric improved the efficiency of cognitive decision-making. Xgboost/Random Forest homogenous ensembling and a highly heterogeneous ensemble approach showed high performance across multifaceted aspects of ML performance and were superior to traditional recalibration methods. Time-dependent ensemble combination of variables, having differing qualities according to time of score adoption, enabled previously siloed data to be combined, leading to increased power, clinical interpretability of variables and usage of data. For models to guide clinicians in individual decisions, performance exceeding these multifaceted benchmarks is necessary.

Background Data on the postoperative outcomes for patients with infective endocarditis complicated by an aortic root abscess is sparse due to the condition’s low incidence and high mortality rates. This systematic review and meta-analysis aims to evaluate existing data on the impact of aortic root abscesses (ARA) on the postoperative outcomes of surgically managed infective endocarditis (IE) and to inform optimal surgical approach. Methods The online databases MEDLINE, EMBASE and Cochrane library were searched from 1990 to 2022 for studies comparing ARA with NARA (no ARA) in infective endocarditis. Data was extracted by two independent investigators and aggregated in a random-effects model (Review Manager version 5.3). Risk of bias was assessed using an adapted version of the Newcastle-Ottawa scale. Results Six clinical studies were included in the meta-analysis (n = 1982). The ARA group was associated with an increased risk of in-hospital mortality (OR = 1.74 96% CI 1.18-2.56) and late mortality (HR = 1.27 95% CI 1.03-1.58). The reoperation meta-analysis was complicated by high rates of heterogeneity (I = 59%) and found no significant differences in reoperation between group ARA and NARA (no ARA) (HR = 1.48; 95% CI 0.92-2.40). Post-hoc scatter graph showed a strong linear relationship (r=0.998), suggesting hospitals with higher rates of aortic root replacement (ARR) achieve lower rates of reoperation for ARA patients compared with PR. Conclusions The presence of an ARA in aortic valve endocarditis is associated with elevated early and late mortality despite modern standards of care. Additionally, ARR should be considered to have a favourable postoperative profile for use in this context.

Significant dilemma exists regarding management of the aortic root pathology in acute aortic dissections. Several strategies for both repair and replacement exist and there is a lack of clarity on the superiority of one over the other. Important factors that influence management strategies include involvement of the sinuses, competence of the aortic valve, presence of Marfan’s syndrome and connective tissue disorders, as well as availability of surgical expertise. The wide variability in these factors makes it unlikely for any one technique to be suitable for management of all aortic roots and the root pathology has to be tailored to an individual patient.

Our earlier work has shown inter‑disease and intra‑disease differences in the cardiac proteome between right (RV) and left (LV) ventricles of patients with aortic valve stenosis (AVS) or coronary artery disease (CAD). Whether disease remodeling also affects acute changes occuring in the proteome during surgical intervention is unknown. This study investigated the effects of cardioplegic arrest on cardiac proteins/phosphoproteins in LV and RV of CAD (n=6) and AVS (n=6) patients undergoing cardiac surgery. LV and RV biopsies were collected during surgery before ischemic cold blood cardioplegic arrest (pre) and 20 min after reperfusion (post). Tissues were snap frozen, proteins extracted, and the extracts were used for proteomic and phosphoproteomic analysis using Tandem Mass Tag (TMT) analysis. The results were analysed using QuickGO and Ingenuity Pathway Analysis softwares. For each comparision, our proteomic analysis identified more than 3,000 proteins which could be detected in both the pre and Post samples. Cardioplegic arrest and reperfusion were associated with significant differential expression of 24 (LV) and 120 (RV) proteins in the CAD patients, which were linked to mitochondrial function, inflammation and cardiac contraction. By contrast, AVS patients showed differential expression of only 3 LV proteins and 2 RV proteins, despite a significantly longer duration of ischaemic cardioplegic arrest. The relative expression of 41 phosphoproteins was significantly altered in CAD patients, with 18 phosphoproteins showing altered expression in AVS patients. Inflammatory pathways were implicated in the changes in phosphoprotein expression in both groups. Inter‑disease comparison for the same ventricular chamber at both timepoints revealed differences relating to inflammation and adrenergic and calcium signalling. In conclusion, the present study found that ischemic arrest and reperfusion trigger different changes in the proteomes and phosphoproteomes of LV and RV of CAD and AVS patients undergoing surgery, with markedly more changes in CAD patients despite a significantly shorter ischaemic period.

The incidence of stroke after coronary artery bypass grafting (CABG) is around 1.3% in the Society of Thoracic Surgeons database but carries a mortality of almost 20% (1,2). The stroke rate is even higher with aortic valve replacements with the Determining Neurologic Outcomes from Valve Operations (DeNOVO) study reporting stroke rates as high as 17% (3). It is also likely that variations in definition of stroke leads to underreporting of this event. There is thus, no denying that stroke remains the Achilles heel of cardiac surgery and efforts must be made to mitigate its occurrence.

ObjectivesTo prevent the emergence of new waves of COVID-19 caseload and associated mortalities, it is imperative to understand better the efficacy of various control measures on the national and local development of this pandemic in space–time, characterise hotspot regions of high risk, quantify the impact of under-reported measures such as international travel and project the likely effect of control measures in the coming weeks.MethodsWe applied a deep recurrent reinforced learning based model to evaluate and predict the spatiotemporal effect of a combination of control measures on COVID-19 cases and mortality at the local authority (LA) and national scale in England, using data from week 5 to 46 of 2020, including an expert curated control measure matrix, official statistics/government data and a secure web dashboard to vary magnitude of control measures.ResultsModel predictions of the number of cases and mortality of COVID-19 in the upcoming 5 weeks closely matched the actual values (cases: root mean squared error (RMSE): 700.88, mean absolute error (MAE): 453.05, mean absolute percentage error (MAPE): 0.46, correlation coefficient 0.42; mortality: RMSE 14.91, MAE 10.05, MAPE 0.39, correlation coefficient 0.68). Local lockdown with social distancing (LD_SD) (overall rank 3) was found to be ineffective in preventing outbreak rebound following lockdown easing compared with national lockdown (overall rank 2), based on prediction using simulated control measures. The ranking of the effectiveness of adjunctive measures for LD_SD were found to be consistent across hotspot and non-hotspot regions. Adjunctive measures found to be most effective were international travel and quarantine restrictions.ConclusionsThis study highlights the importance of using adjunctive measures in addition to LD_SD following lockdown easing and suggests the potential importance of controlling international travel and applying travel quarantines. Further work is required to assess the effect of variant strains and vaccination measures.

Transcatheter aortic valve implantation (TAVI) is rapidly spreading across the world with the endorsement of the cardiological community(1) and the supporting results of randomised controlled trials (2,3). However, TAVI-related complication like aortic dissection, aortic valvular rupture, or left ventricle perforation are still potentially catastrophic (4).

Hybrid coronary revascularization (HCR) consists of left internal thoracic artery (LITA) graft to the left anterior descending (LAD) artery and transcatheter revascularization of the non-LAD stenosis in specific settings to achieve complete coronary revascularization. Technique to perform the LITA to LAD graft has ranged from median sternotomy with cardiopulmonary bypass to robotically assisted totally endoscopic coronary bypass surgery using beating heart revascularization.

The landmark 2016 Minimal Invasive Extracorporeal Technologies International Society (MiECTiS) position paper promoted the creation of a common language between cardiac surgeons, anesthesiologists and perfusionists which led to the development of a stable framework that paved the way for the advancement of minimal invasive perfusion and related technologies. The current expert consensus document offers an update in areas for which new evidence has emerged. In the light of published literature, modular minimal invasive extracorporeal circulation (MiECC) has been established as a safe and effective perfusion technique that increases biocompatibility and ultimately ensures perfusion safety in all adult cardiac surgical procedures, including re-operations, aortic arch and emergency surgery. Moreover, it was recognized that incorporation of MiECC strategies advances minimal invasive cardiac surgery (MICS) by combining reduced surgical trauma with minimal physiologic derangements. Minimal Invasive Extracorporeal Technologies International Society considers MiECC as a physiologically-based multidisciplinary strategy for performing cardiac surgery that is associated with significant evidence-based clinical benefit that has accrued over the years. Widespread adoption of this technology is thus strongly advocated to obtain additional healthcare benefit while advancing patient care.

Introduction: Female sex is considered an independent risk factor for mortality and morbidity following cardiac surgery. This study is the first to review the UK national database to compare outcomes following surgical revascularisation and valvular cardiac procedures between females and males. Hypothesis: Females have worse outcomes following cardiac surgery than males. Methods: Using data from National Adult Cardiac Surgery Audit (NACSA), we identified all elective and urgent, isolated coronary artery by-pass grafting (CABG), aortic valve replacement (AVR) and mitral valve replacement/repair (MVR) procedures from 2010-2018. We compared baseline data, operative data and outcomes of mortality, stroke, renal failure, deep sternal wound infection, return to theatre for bleeding and length of hospital stay. Multivariable logistical/linear regression models were used to assess relationships between sex and our outcomes, adjusting for baseline characteristics. Results: Females, compared to males, had a greater odds of experiencing 30-day mortality in each procedure (CABG OR 1.76, CI 1.47-2.09, p Conclusions: Despite advances in cardiac surgery, females in the UK have an increased risk of short-term mortality after cardiac surgery compared to males. This highlights the need to focus on the understanding of the causes behind these disparities and therefore implementation of strategies to improve this.

Introduction: Despite advances in cardiac surgery, there is evidence from observational studies which suggests that females have poorer post-operative outcomes than males. This study is the first to review sex related outcomes following both coronary artery bypass graft (CABG) and valve surgery with or without combined CABG. Hypothesis: Females have worse outcomes following cardiac surgery than males. Methods: We identified 30 primary research articles reporting either short-term mortality (in-hospital/30 day), long-term mortality, post-operative stroke, sternal wound infection and post-operative myocardial infarction (MI) in both sexes following CABG and valve surgery with or without combined CABG Reported adjusted odds/hazard ratio were pooled using an inverse variance model. Results: Females were at higher risk of short-term mortality (odds ratio (OR) 1.40; 95% confidence interval (CI) 1.32-1.49; I 2 =79%) and post-operative stroke (OR 1.2; CI 1.07-1.34; I 2 =90%) when compared to males. There was no increased risk in long-term mortality (OR 1.04; 95% CI: 0.93-1.16; I 2 =82%), post-operative MI (OR 1.22; 95%CI: 0.89-1.67; I 2 =60%) or deep sternal wound infection (OR 0.92; 95%CI: 0.65-1.03, I 2 =87%). No evidence of publication bias or small study effect was found. Conclusions: Females are at a greater risk of short-term mortality and post-operative stroke than males following CABG and valve surgery with or without combined CABG. However long-term mortality is equivalent in both sexes.

OBJECTIVES Benefits of using multiple arterial grafting (MAG), over single arterial grafting in major adverse cardiac event rates and the need for repeat revascularization, have been widely reported. Several guidelines have recommended the use of MAG in selected patients. We report the trend of MAG in patients undergoing isolated coronary artery bypass grafting (CABG) in the UK. METHODS This is a retrospective analysis of a prospectively collected UK national database in patients undergoing non-emergency, isolated CABG from 1996 to 2018. Patients were divided into single arterial grafting and MAG, and trends in perioperative characteristics were analysed. RESULTS A total of 336 321 patients were included, of whom 284 003 (84.44%) received single arterial grafting and 52 318 (15.56%) received MAG. The use of MAG after an initial increase from 1996 to 2001, steadily decreased thereafter, particularly in the use of radial artery. MAG was likely to be performed in younger patients [66.72 (standard deviation: 9.22) vs 62.30 (standard deviation: 10.06), P CONCLUSIONS Our data show that the use of MAG in CABG in the UK after an initial increase from 1996 to 2001 steadily decreased thereafter until 2018. This is likely to be multifactorial and a better understanding of the main causes may contribute to establishing the best indication for MAG in everyday clinical practice.

Robotic totally endoscopic techniques to perform the LITA to LAD graft, coupled with PCI, provides the least invasive option to achieve hybrid coronary revascularization (HCR). Shorter hospital stay and reduced need for blood transfusions have been consistently being reported by several studies along with similar long-term outcomes. Considerable variations exist in the definition of HCR which can be single or two-staged with surgical revascularization being carried out after PCI or vice versa. Variations also exist with respect to usage of cardiopulmonary bypass, surgical incisions, and use of minimally invasive robotic techniques. The different strategies of HCR do not lead to similar outcomes and the findings of one strategy cannot be extrapolated to the entire group. Studies reporting different strategies of HCR, should ideally provide more granular data when reporting outcomes.

Atopic dermatitis (AD) prevalence is rising worldwide. Literature data suggest the incidence of AD in developing countries is gradually getting close to that of developed ones, in which AD affects 20% of the paediatric population. Such an increment, associated with significant variations in prevalence among the various countries, underlines the importance of environmental factors in the disease onset. Among these, great importance is given to hygiene, intestinal microbiota, exposure to bacterial endotoxins, outdoor living with contact to animals, atmospheric pollution, weather, and diet. Genetic (alteration of the skin barrier function) as well as immunologic factors concur with the environmental ones. Only the systematical study of all these elements can best elucidate AD epidemiology.

From the birth, children’s skin is exposed to numerous environmental stimuli and can therefore be affected by various pictures of contact dermatitis. Irritant contact dermatitis of the napkin area is linked to various factors (friction between skin and diaper, maceration of skin, occlusion, urinary pH, urine, and feces). The eruption does not generally manifest before the third week of life, with a peak between the seventh and twelfth week. The dermatitis is evident on convex surfaces in direct contact with the diaper. It nearly always responds to treatment and resolves when diapers are no longer used. Contact cheilitis and perioral dermatitis, linked to irritant contact with food, can develop above all in the first 2–3 years of life. The irritation can also be induced by saliva, especially if the child continually licks the lips and surrounding skin. Contact sensitization and allergic contact dermatitis are common in children and more frequent than believed. The frequence of contact allergy increases with the age, related to increased exposure to environmental allergens (metals, pharmaceutical products, skin care products and cosmetics, toys, shoes and sport equipment, tattoos). Patch testing in pediatric patients is considered safe; the general view is that children can tolerate the same patch test concentration as adults.

Contact dermatitis is the most frequent form (60%) of all the eczematous dermatoses and is among the most common diseases observed in dermatology and in occupational medicine. It is widespread in both occupational and non occupational settings: in the former case the incidence ranges from 85 to 98% of all job-related skin diseases; the peak prevalences are recorded in the building, leather, rubber, metallurgy, food, and chemical industries; health staff and apprentice hairdressers are also at high risk. From the aetiopathogenic and clinical standpoints, contact dermatitis can be subdivided into various types of reactions (irritant contact dermatitis, allergic contact dermatitis, photocontact dermatitis, noneczematous contact dermatitis, systemic contact dermatitis, and contact urticaria). Among these reactions, irritant contact dermatitis shows a more prevalent incidence today than contact allergy, for various reasons. The clinical differences among the various forms of contact dermatitis are due to a number of factors, especially the type of contact (exogenous, direct or airborne, and endogenous; the latter comes into action in subjects who have been prior sensitized by exogenous route, as occurs in case of systemic contact dermatitis), the chemical characteristics of particular causal agents, and the underlying pathogenic mechanisms in each case. A recent meta-analysis shows that one in five subjects from the general population suffers from contact allergy. The most common allergen is nickel, followed by fragrance mix, cobalt, balsam of Peru, chromium, paraphenylenediamine, isothiazolinones, and colophony. Various data demonstrate that seasonal factors can also affect the incidence of contact dermatitis.

In both the occupational and non occupational fields, prevention is subdivided in primary (both collective and individual, aimed at elimining the risk of contact dermatitis in a population of healthy individuals), secondary (to avoid relapses in subjects affected by contact dermatitis), and tertiary (aimed to block the progression of the disease, and to circumvent subject’s inhability to work). The various primary and secondary collective and individual prevention measures are discussed: among them, closed systems and automation in occupational field, allergen removal or replacement, predictive tests, dermatologic visit, worker protection (gloves, clothing), barrier creams, and skin care are crucial aspects of the prevention. In the case of occupational contact dermatitis, all efforts must be made to allow the worker to continue with the usual job. However, there are various conditions that may justify a change of work. Therefore, multidisciplinary care, medical and social (social institutions, trade unions, work inspectors, employers, dermatologists, occupational medicine specialists, rehabilitation specialists) is essential. This contribution to the treatment is, of course, regulated by the national norms in each country.

Irritant contact dermatitis is a non immunological local inflammatory skin reaction to external agents. The related skin damage can be the result of acute toxic aggression, generally linked to a single strong etiological agent, or of repeated cumulative aggression by several weaker irritants. Contact irritation is mediated by a complex pathogenic mechanism, and the same substance can induce different clinical features depending on the concentration. There are various classes of irritants, and their action on the skin varies greatly, as do the cellular and non cellular skin targets. Generally, irritant contact dermatitis is regarded as more common than allergic contact dermatitis, especially in the occupational setting. From the clinical- morphological standpoint, contact irritation can present with many highly variable pictures according to the type of irritant substance. While contact allergy is subjectively characterized by pruritus, irritation can manifest as burning, stinging, or smarting, sometimes with no objective clinical signs (subjective reactions to irritants). In general, the diagnosis of irritant contact dermatitis seems to pose less difficulties in the occupational field, where the conditions of exposure are normally under close control. The methods for use in humans to study the irritant power of a substance are the patch tests and other skin tests, and non invasive methods (evaporimetry and laser Doppler flowmetry). According to various authors, patients with irritant contact dermatitis have a poorer prognosis than those with allergic contact dermatitis. Bearing in mind the high incidence of this affliction, various prevention rules must be recognized as very important.

An important etiopathogenic and clinical aspect of allergic contact dermatitis is the persistence, recurrence or spread of the disease following the introduction by systemic route of the allergen or of other cross-reacting substances. This is what occurs in the systemic contact dermatitis phenomenon, a condition that arises in subjects who have undergone prior sensitization through skin contact. There are various routes of expoxure that elicit the eruption (inhalation, oral, intramuscular, intravenous, rectal, vesical, subcutaneous, and inplants within the body). Clinically, the onset of the eruption occurs rapidly, within a few hours after exposure, and manifests with skin and systemic (headache, arthralgia, fever, diarrhea, nausea, muscle ache, etc.) signs. Among the various skin symptoms, the flare-up of previous positive patch tests raise the suspicion of systemic contact dermatitis, and is a fashinating and specific sign of the eruption. Characteristic and frequently obverved are the generalized rashes (maculo-papulo-vesicular rash, erythema multiforme-like rash, purpuric and urticarioid rashes). Among the localized skin rashes, the vesicular hand eczema is common, prevalently in nickel-sensitized subjects. The baboon syndrome is a characteristic but rare eruption on the buttocks, in the genital area and a V-shaped reaction on the inner things. Various medicaments, metals, foods, plants, and other chemicals may be implicated as causative agents. Systemic contact dermatitis presents with a vast spectrum of differential diagnosis, ranging from infections to bullous diseases.

Plant contact dermatitis, that is of the great clinical concern, is caused by contact with flowers, trees, grass, fruits, weeds, vegetables, and pollens. The contact with these agents is direct (the most frequent) or indirect through medicaments and cosmetics containing plant extracts, or various plant-based foods, industrial products, and herbal remedies (less frequent). Responsable of phyto- and phytophotocontact dermatitis are various plant families with their numerous irritant and/or sensitizing chemicals. The irritant forms of contact dermatitis can be of a mechanical (owing to the presence of prickles, spines, and thorns) or chemical (fluids and crystals in the different portions of the plant) nature. A characteristic picture of allergic contact dermatitis, usually of occupational origin, is the eczema of the fingertips with fissured, hyperkeratotic and painful lesions, observed in tulip pickers and in people handling bulbs and garlic. Some plants (walnut, henna) can induce a primary contact hyperpigmentation. The combined action of various plants (Umbelliferae, Rutaceae, Moraceae, etc.) on the skin and the exposure to the sun is the cause of the photophytocontact dermatitis. The phototoxic contact reactions presents with different clinical pictures: a classic eczematous eruption, the dermatitis bullosa striata pratensis, and the berloque dematitis. Some cases of photoallergic contact reactions to furocoumarins are reported. Frequently reported are also cases of phytoairborne allergic contact dermatitis. The clinical-etiological and botanical investigation of plant contact dermatitis is often very difficult, since it is necessary to take into account the patient’s occupation, hobbies, any recent outdoors excursions, and the identification of the species of the plant. Finally, it is important to consider the possible evidence of a pseudophytodermatitis linked to contact with parasites (mites), that infest plants or their products.

Airborne dermatoses are complaints linked to external environmental, chemical and biotic agents carried through the air. In general, airborne dermatoses, that are most common in work environment, tend to cause diagnostic problems that are challenging for both the patient and the doctor. It should also be borne in mind that since the external culprit agents are present in the environment, they do not only come in contact with the skin and mucosa, but can also be inhaled or ingested, thus also causing respiratory and systemic symptoms. There is considerable variation in the nature of airborne contactants and in their form of presentation: vapours and gases, droplets, solid nonbiotic particles, and solid biotic particles. Particular physical conditions (low environmental humidity, high temperatures) can often predispose to the development of airborne dermatoses, as well as some constitutional factors (atopic dermatitis, seborrhoeic dermatitis). Among the various clinical forms, airborne contact dermatitis interests the parts of the body exposed to the air: face, neck, upper aspect of the chest, hands, wrists. These cases must firstly be differentiated from photocontact dermatitis; in the latter case, however, shadowed anatomic areas such as the upper eyelids, behind the ears, the submandibular region, and under the hair are not affected. Various examples of airborne irritant and allergic contact dermatitis and airborne photocontact dermatitis are reported in literature. Another common airborne dermatitis, in particular in Mediterranean coastal regions, is the processionary dermatitis due to the caterpillar Thaumetopoea pityocampa, which induces disruptive effects on pines, man and pets. The cutaneous, respiratory and ophthalmic simptoms are due to particular removable urticarial hairs growing dorsally on the first 8 abdominal larva segments. Chloracne, caused by halogenated aromatic hydrocarbons, is a variety of occupational acne. The most potent acnegens are chloro- and bromo-substituted aromatic hydrocarbons (dioxins), used in various work environments. Human exposure to dioxins can occur due to environmental, occupational, or accidental pollution. The skin is a key organ indicating exposure to dioxin chemicals. The characteristic cutaneous manifestations generally appear about two weeks after the exposure, reach a peak after 6–10 months and can persist for years due to the very slow decrease of dioxins in skin.