Chloracne: a case series on cutaneous expression of CYP1A1 as diagnostic biomarker.

Chloracne, also known as metabolizing acquired dioxin-induced skin hamartomas (MADISH), is a rare disfiguring disease related to dioxin exposure. There is a paucity of literature on the clinical manifestations and pathogenesis of chloracne/MADISH. The aim of this study was to assess the clinical features of this very unusual acneiform eruption and to explore the pathogenesis of the disease. This was a retrospective, observational report study was conducted on five patients belonging to the same nuclear family (father, mother and three children) and a relative (father's brother) living in the same house. Histopathological, immunohistochemical, laboratory and toxicological analyses were performed for all patients. The results suggest that CYP1A1 in human skin is a diagnostic biomarker in chloracne, and was positive for all the patients in our sample. Tetrachlorodibenzo-p-dioxin is the most investigated dioxin responsible for chloracne; however, several other agonists, whether dioxin-like or not, can activate the aryl hydrocarbon receptor. To our knowledge, this Italian case series is the first study to suggest polychlorinated biphenyls as a possible cause of an overstimulation of aryl hydrocarbons causing the consequent acneiform eruption.

A New Insight into the Potential Role of Tryptophan-Derived AhR Ligands in Skin Physiological and Pathological Processes.

The aryl hydrocarbon receptor (AhR) plays a crucial role in environmental responses and xenobiotic metabolism, as it controls the transcription profiles of several genes in a ligand-specific and cell-type-specific manner. Various barrier tissues, including skin, display the expression of AhR. Recent studies revealed multiple roles of AhR in skin physiology and disease, including melanogenesis, inflammation and cancer. Tryptophan metabolites are distinguished among the groups of natural and synthetic AhR ligands, and these include kynurenine, kynurenic acid and 6-formylindolo[3,2-b]carbazole (FICZ). Tryptophan derivatives can affect and regulate a variety of signaling pathways. Thus, the interest in how these substances influence physiological and pathological processes in the skin is expanding rapidly. The widespread presence of these substances and potential continuous exposure of the skin to their biological effects indicate the important role of AhR and its ligands in the prevention, pathogenesis and progression of skin diseases. In this review, we summarize the current knowledge of AhR in skin physiology. Moreover, we discuss the role of AhR in skin pathological processes, including inflammatory skin diseases, pigmentation disorders and cancer. Finally, the impact of FICZ, kynurenic acid, and kynurenine on physiological and pathological processes in the skin is considered. However, the mechanisms of how AhR regulates skin function require further investigation.

RASopathic comedone-like or cystic lesions induced by vemurafenib: a model of skin lesions similar but not identical to those induced by dioxins MADISH.

BACKGROUND: Patients treated with vemurafenib for metastatic melanoma often develop skin lesions similar to those observed after exposure to dioxin-like compounds. We previously called these lesions MADISH (metabolizing acquired dioxin-induced skin hamartoma) when analysing a case of acute dioxin poisoning. OBJECTIVE: We performed a clinical trial aimed at comparing the skin lesions observed under vemurafenib treatment with MADISH in order to bring to light a possible crosstalk between vemurafenib and dioxin pathways. METHODS: In this case series study, we explored the histological aspect of skin lesions in 10 cases treated with vemurafenib for malignant melanoma. We also analysed the ability of vemurafenib and tyrosine kinase inhibitors to induce dioxin-AhR pathway. RESULTS: All patients had skin lesions diagnosed as 'non-inflammatory acneiform eruption' by dermatologists. These were predominantly facial with notable retroauricular involvement and clinically compatible with chloracne/MADISH when assessed by dioxin expert. Histological analysis showed mostly comedone-like lesions and dermal cysts containing epithelial wall with basal or lateral epithelial projections and lamellar keratinization and alterations of remaining sebaceous glands. The expression of CYP1A1, a gene highly induced following dioxin exposure, was not observed in these lesions. Vemurafenib and the tyrosine kinase inhibitors erlotinib and gefitinib did not induce CYP1A1 activity. DISCUSSION: Although the skin lesions under vemurafenib treatment were morphologically similar to MADISH, the absence of CYP1A1 expression in dermal cysts of patients and the absence of CYP1A1 activation by vemurafenib led us consider that these skin lesions were different from true MADISH and not mediated by a crosstalk of AhR signalling, but rather to a hyperactivation of PI3K-Akt pathway as a consequence of vemurafenib treatment. A strong expression of CYP1A1 in the epithelial wall of dermal cysts must be required, parallel to the morphology of the lesions, to make the diagnosis of MADISH, the hallmark of an exposure to dioxin-like/chloracnegen compounds.

Chloracne in a Farming Family.

An 11-year-old boy presented with a 1-year history of multiple comedonal lesions distributed over his body. The lesions (Figure 1) were densely distributed throughout his body. Ophthalmologic examination revealed hyperpigmented conjunctival mucosae and enlarged meibomian glands (Figure 2). His nails were also hyperpigmented. In addition, he had been coughing and had a fever, each present for a month. Significant laboratory studies included mild anemia (hemoglobin 11.6 gm%) and leukocytosis of 20,800. A chest x-ray was suggestive of interstitial lung disease. Similar lesions were present on his two siblings and parents. Additionally, his father had developed multiple, acne-like lesions, large abscesses, palmar and plantar peeling, and severe jaundice with hepatic failure. He had a history of frequent exposure to a pesticide mixed with a herbicide, as a result of leakage from a spray container. The patient was diagnosed with chloracne, based on the history, clinical features, and histologic examination.

Occluded Cigarette Smoke Exposure Causing Localized Chloracne-Like Comedones.

Many environmental acne disorders, including chloracne and oil acne, were previously thought to occur predominantly in occupational settings following polycyclic aromatic hydrocarbon exposure. Cigarette smoke has also been shown to contain a large number of these toxic polycyclic aromatic hydrocarbon components and strictly correlates with noninflammatory acneiform lesion development in postadolescent patients. We report a case of localized open comedones associated with occluded cigarette smoke exposure near the nasal cavity due to infrequently changed gauze following rhinectomy. The dermal uptake of polycyclic aromatic hydrocarbon components in cigarette smoke has the potential to function as a contributing factor in chloracne development. Several of these environmental and noninflammatory acne subtypes may share a common molecular propensity for enhanced comedogenesis originating from aryl hydrocarbon receptor pathway effects in the skin. Additional studies are needed to further elucidate the exact mechanistic pathways through which tobacco smoke impacts the integumentary system.

Aryl Hydrocarbon Receptor Activation in Acne Vulgaris Skin: A Case Series from the Region of Naples, Italy.

BACKGROUND: Dioxins are persistent organic pollutants present in the environment. They exert their biological effects by binding to an intracellular receptor, the aryl hydrocarbon receptor (AhR). Activation of AhR leads to the induction of cytochrome p450 1A1 (CYP1A1). Expression of CYP1A1 in human skin is a key marker for AhR activation, and it may induce comedogenesis resulting in acne-like lesions known as chloracne/metabolising acquired dioxin-induced skin hamartomas (MADISH). The contribution of this pathway in patients seen in a busy acne clinic is unknown. MATERIALS AND METHODS: We explored the expression of CYP1A1 by immunohistochemistry in the acne lesions of 16 patients living in the region of Naples, Italy, where epidemiological studies have suggested a possibly increased exposure to environmental dioxins. A composite score to outline potential components of the chloracne/MADISH histological pattern was used. RESULTS: CYP1A1 expression was observed in 11 lesions (69%) and was distributed in sebaceous glands, follicular epithelium, cystic wall and endothelial cells. The histological score for chloracne/MADISH was 'likely' in 3 cases and 'possible' in 11 cases. Compared to current data on CYP1A1 expression in the skin of 67 patients with proven exposure to AhR agonists, these data indicate a high incidence of AhR activation in this series. CONCLUSION: This is the first study analysing AhR activation in skin in a series of patients from a hospital-based acne clinic. It provides information for future controlled prospective studies. The significance of CYP1A1 expression in terms of AhR ligand exposure is discussed.

Accidental exposure to polychlorinated biphenyls (PCB) in waste cargo after heavy seas. Global waste transport as a source of PCB exposure.

OBJECTIVES: After cargo with PCB-containing transformer oil waste was damaged in heavy seas, the vessel crew exposed to PCB developed itching and acne-form eruption of the skin. The objective of our study was to analyse this work-related incident and its effects on health. METHODS: Air and wipe test samples were taken in the ship for analysis of PCB (28/52/101/138/153/180); clinical investigations of all seafarers (n = 6) included lung function, chest X-ray, clinical chemistry and biomonitoring (plasma PCBs, chlorophenols in urine) measured after a latency of 7 weeks. The biomonitoring data were adjusted according to age-related reference values and validated against controls (n = 96). RESULTS: Biomonitoring showed elevated PCB-28-/52/-102/-138 congeners (mean 1.16/0.91/136, ∑PCB: 5.82 µg/l), which correlates with the dust samples from the cargo hold (∑PCB. 9,440 mg/m(2)) and with 6.1 and 5.0 µg/m(3) in stern and bow cargo air samples. IgE elevation in two seafarers and substantial blood sedimentation rate increase with anaemia or pulmonary emphysema were unlikely to be caused by PCB exposure. Although two members showed slightly elevated airway resistance values, other lung function parameters were normal and reactive airways dysfunction syndrome due to PCBs could be excluded. Elevated chlorophenols in urine could contribute to the manifestation of chloracne. CONCLUSIONS: PCB-52/-101/-138 found in plasma and in air samples confirm exposure to PCB. Acne-form skin eruptions were from occupational exposure to polychlorinated biphenyls in the spilt transformer oil. There were no other abnormal findings in medical and clinical examinations that could be attributed to PCBs. This does not exclude possible long-term effects.

t(14;18) Translocations in Dioxin-Exposed Workers.

OBJECTIVE: To determine if occupational exposure to dioxins is associated with an increased frequency of t(14;18) translocations. METHODS: A cross-sectional analysis of serum dioxin levels and t(14;18) frequencies in peripheral blood mononuclear cells in 218 former chemical plant workers and 150 population controls. RESULTS: The workers had significantly higher geometric mean serum levels of 2,3,7,8-TCDD (26.2 vs 2.5 ppt) and TEQ (73.8 vs 17.7 ppt) than controls. There were no significant differences in the prevalence or frequency of t(14;18) translocations in the workers compared to controls. Among former workers with current or past chloracne who were t(14;18) positive, the frequency of translocations significantly increased with quartiles of 2,3,7,8-TCDD and TEQ. CONCLUSION: Chloracne appears to modulate the association between dioxin exposure and increased frequency of t(14;18) translocations.

Proceedings of the 2010 National Toxicology Program Satellite Symposium.

The 2010 annual National Toxicology Program (NTP) Satellite Symposium, entitled "Pathology Potpourri," was held in Chicago, Illinois, in advance of the scientific symposium sponsored jointly by the Society of Toxicologic Pathology (STP) and the International Federation of Societies of Toxicologic Pathologists (IFSTP). The goal of the annual NTP Symposium is to present current diagnostic pathology or nomenclature issues to the toxicologic pathology community. This article presents summaries of the speakers' presentations, including diagnostic or nomenclature issues that were presented, along with select images that were used for voting or discussion. Some topics covered during the symposium included a comparison of rat and mouse hepatocholangiocarcinoma, a comparison of cholangiofibrosis and cholangiocarcinoma in rats, a mixed pancreatic neoplasm with acinar and islet cell components, an unusual preputial gland tumor, renal hyaline glomerulopathy in rats and mice, eosinophilic substance in the nasal septum of mice, INHAND nomenclature for proliferative and nonproliferative lesions of the CNS/PNS, retinal gliosis in a rat, fibroadnexal hamartoma in rats, intramural plaque in a mouse, a treatment-related chloracne-like lesion in mice, and an overview of mouse ovarian tumors.

Chloracne-like drug eruption associated with sorafenib.

Sorafenib is a chemotherapeutic agent primarily used to treat metastatic renal cell carcinoma. It is a multikinase inhibitor that blocks cell proliferation and angiogenesis. Numerous cutaneous side effects have been reported in association with this medication, including acral erythema, inflammation of actinic keratoses, erythema multiforme, vasculitis, and keratoacanthomas. Up to 40 percent of patients on this medication develop dermatologic manifestations. We describe chloracne-like eruptions in two different patients with no exposure to aromatic hydrocarbons but who were recently started on sorafenib for treatment of metastatic renal carcinoma. The primary reason for discontinuation of sorafenib is secondary to its adverse side effect profile. Recognizing these effects early and administering appropriate treatment will likely increase medication compliance and minimize both dose reductions and discontinuation of the medication resulting in optimal treatment outcomes.

Chloracne: still cause for concern.

Chloracne, first described by Herxheimer in 1899, is a dermatosis consisting of more or less diffuse acneiform lesions distributed prevalently on the face and on body areas not usually affected by acne and caused by chronic or acute exposure to halogenated chemical compounds. Dioxin is the common name for dibenzo-p-dioxins and dibenzofurans, contaminants nearly ubiquitous in the environment and highly resistant to chemical and biological degradation. These compounds can survive for decades in the environment and accumulate in the human and animal food chains. Chloracne is characterized by the onset of numerous comedo-like lesions and yellowish cysts on the face, particularly on the cheeks, that can spread to the trunk and other body regions not usually affected by acne vulgaris, with diffuse grayish skin pigmentation and sometimes associated with hypertrichosis and areas of folliculitis. The lesions may occasionally be accompanied by skin or systemic manifestations. We report 9 cases of chloracne, 8 of them with rapid onset in patients residing in the same building, and 1 in a patient occupationally exposed to halogenated compounds. In our series, the doses of dioxin and polychlorinated biphenyls in the soil, water and plant material, and the serum titer of dioxin were within the normal range. This consideration raises the issue of the need to revise the serum threshold for dioxin poisoning and the environmental threshold. We wish also to underline the value of dermatopathology in the differential diagnosis of chloracne.

Chloracne in seven organic chemists exposed to novel polycyclic halogenated chemical compounds (triazoloquinoxalines).

Chloracne is an acneiform eruption caused though poisoning by aromatic compounds (usually halogenated) showing a specific molecular configuration. We describe an outbreak of chloracne among seven discovery chemists who synthesized novel polycyclic halogenated chemical compounds which were classified as triazoloquinoxalines, not known to be chloracnegenic. The diagnosis of chloracne, made clinically, elicited a thorough risk assessment and monitoring programme by the occupational health department. The chemists were investigated by serum excretion rates, skin sampling for Propionibacterium acnes, skin biopsy and laboratory blood investigations. Sebum excretion was normal in five cases, raised in one case and severely reduced in another. Skin levels of P. acnes were normal in all patients except for the one subject who had low sebum excretion, in whom they were undetectable. One subject had a slightly raised serum level of alanine aminotransferase. There were no other signs of systemic toxicity. Two subjects were treated with an oral antibiotic, two received topical therapy only and three required no treatment at all. The patients have had thorough health surveillance at 6-monthly and yearly intervals. In each case the chloracne mostly resolved within 18-24 months although on examination about 3 years later, five of the seven still showed minor changes of chloracne. This outbreak emphasizes the need for vigilance in discovery science. The triazoloquinoxalines were not previously recognized as being chloracnegens although their chemical characteristics were subsequently identified as being in keeping with other chemicals that can cause chloracne. Chloracne can be a difficult diagnosis to make when it occurs in a novel setting: occupational physicians and dermatologists need to be vigilant when dealing with unusual eruptions in discovery chemists.

Chloracne and Hyperpigmentation Caused by Exposure to Hazardous Aryl Hydrocarbon Receptor Ligands.

Dioxins and dioxin-like compounds are environmental pollutants that are hazardous to human skin. They can be present in contaminated soil, water, and air particles (such as ambient PM2.5). Exposure to a high concentration of dioxins induces chloracne and hyperpigmentation. These chemicals exert their toxic effects by activating the aryl hydrocarbon receptor (AHR) which is abundantly expressed in skin cells, such as keratinocytes, sebocytes, and melanocytes. Ligation of AHR by dioxins induces exaggerated acceleration of epidermal terminal differentiation (keratinization) and converts sebocytes toward keratinocyte differentiation, which results in chloracne formation. AHR activation potently upregulates melanogenesis in melanocytes by upregulating the expression of melanogenic enzymes, which results in hyperpigmentation. Because AHR-mediated oxidative stress contributes to these hazardous effects, antioxidative agents may be potentially therapeutic for chloracne and hyperpigmentation.

Expression of AhR, CYP1A1, GSTA1, c-fos and TGF-alpha in skin lesions from dioxin-exposed humans with chloracne.

Occupational exposure to certain polychlorinated aromatic hydrocarbons such as dioxins has been suggested to cause chloracne which is a kind of skin disease. The molecular mechanisms of dioxin-mediated chloracne have not been clarified. It is possible that dioxins contribute to the pathogenesis through activation of aryl-hydrocarbon receptor (AhR)-mediated transcription and downstream genes such as CYP1A1, GSTA1 and TGF-alpha. The study on genes was through chloracne lesional skin, which has rarely been reported on previously. The expression levels of key genes, such as AhR, CYP1A1, GSTA1, c-fos and TGF-alpha in human epidermal tissue of chloracne cases and controls were detected by real-time PCR. Compared with controls, AhR, CYP1A1, GSTA1 and c-fos transactivations were significantly induced in the skins of chloracne patients who had long-term exposure to dioxins and dibenzofuranes. The TGF-alpha mRNA content of epidermal tissue was increased, but not significantly compared with controls. The study demonstrates that constitutive activation of the AhR pathway is probably a prerequisite of chloracne pathogenesis. The changes of genes expression may disturb normal proliferation and differentiation of human epidermis cells, and then lead to chloracne.

Polychlorinated dibenzo-p-dioxins and the human immune system: 4 studies on two Spanish families with increased body burdens of highly chlorinated PCDDs.

The consequences of exposure of people to highly chlorinated polychlorodibenzo-p-dioxins (PCDDs) are much less known than those of TCDD. We report on levels of PCDDs (and PCDFs) in 13 members of two families poisoned by contaminated cooking oil. Originally, all persons displayed chloracne as an early symptom. Persisting hexa- and higher chlorinated PCDDs could be analysed many years after exposure. Highest values found in blood lipids were: OCDD 660,000 pg/g; HpCDD 58,000 pg/g; HxCDDs: 3500 pg/g. None of the participants exhibited increased TCDD levels at the time of study. During a period of 6 years, HpCDD and OCDD disappeared from the blood lipids much faster in persons exposed as children or young adults, than from lipids of their parents. Surface receptors on blood lymphocytes of the members of the two families and the proliferative capacity of these blood cells in the presence of typical stimulants were analysed. Even in family members with the highest body burdens of hexa- to octachlorinated PCDDs we could not detect pronounced changes from a reference population with respect to the immunological markers. Minor deviations of levels of some receptors in a few, but not all, highly exposed persons suggested a similar trend to those reported in previous studies of persons with body burdens of > or =3000 pg TCDD/g blood lipids. An increase in the number of total blood lymphocytes in some subjects exposed as children may have similarity with highly TCDD-exposed children in Seveso.

[Role of mitogen-activated protein kinase pathway in chloracne].

OBJECTIVE: To investigate the role of mitogen-activated protein kinase (MAPK) signal transduction pathway in chloracne. METHODS: Immunohistochemical technique was used to detect the expression of phosphorylated epidermal growth factor receptor (p-EGFR) and p-MAPK proteins in the epithelium of chloracne group and control group. RESULTS: p-EGFR and p-MAPK was found in all chloracne tissues, whereas no expression of p-EGFR and p-MAPK protein was found in control group. In the skin of chloracne patients, p-EGFR was mainly distributed in the membrane and the cytoplasm, especially in the vicinity of membrane; major positive signal of p-MAPK was in core and serosity. CONCLUSION: EGFR and MAPK phosphorylation is found in chloracne tissues. MAPK signal transduction pathway is one important molecular mechanism of chloracne.

Do PCDD/PCDF standard solutions used in dioxin analysis pose a risk as potentially acutely toxic to lab personnel?

Laboratory safety requires protecting personnel from chemical exposures. Working with stock solutions of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/PCDFs) in routine analysis of feed and food with bioanalytical or physicochemical methods raises some concerns. Since PCDD/PCDFs are considered as possibly acutely toxic, the potential risks were evaluated to determine whether supervision of their use is necessary. Based on LD50-data for oral or dermal intake, hazard classification of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) as a substance (category 1) and in commercially available TCDD standard solutions (category 4) is different. As worst case exposure scenario during routine laboratory work it was assumed that a dose of 100 ng TCDD gets onto the skin and is absorbed. This would result in the total body burden of a 70 kg person with 15 kg fat increasing from 10 (upper range of current background levels) to ∼17 pg of toxic equivalents (TEQs) of PCDD/PCDFs per g lipid, a level commonly observed over past decades. Chloracne, the main acute effect occurring weeks after exposure, is observed at much higher blood concentrations than estimated from accidental laboratory exposure. Immunotoxicity, developmental effects and other toxic effects may occur at lower blood levels, but require longer periods to develop. Since acute toxic symptoms don't occur within an "8 h acute time window", no supervision is necessary when working with standard solutions in routine analysis. Nevertheless, precautionary measures are needed regarding long-term adverse health effects and appropriate workplace conditions must exist to ensure that additional occupational exposure to PCDD/PCDFs by laboratory personnel is negligible.