Light cautery and EMLA in the treatment of chloracne lesions

Neuropathy and chloracne induced by 3,5,6-trichloropyridin-2-ol sodium: Report of three cases

BACKGROUND

Chloracne is a rare skin condition that is caused by systemic exposure to halogenated aromatic compounds. The main characteristic of chloracne is blackhead, and in severe cases, it can be accompanied by systemic symptoms. Sodium 3,5,6-trichloropyridin-2-ol (STCP) is a necessary precursor compound for the production of chlorpyrifos and triclopyr, which are extensively used as a pesticide and herbicide, respectively. STCP is also a chlorophenol that has been associated with chloracne. STCP poisoning could induce mild myelin sheath damage. We herein report three cases with chloracne due to exposure to STCP.

CASE SUMMARY

Three young men, aged 29, 33, and 26 years, respectively, in the same workplace had polymorphic skin lesions, characterized mainly by comedones and cysts, and one of them also had acne like lesions in the genital area. These clinical manifestations appeared when they were exposed to STCP for 3 d, 1 wk, and 2 wk, respectively. Among them, polyneuropathy and liver damage occurred. We performed dermoscopy and clinical and laboratory tests on these patients. Additionally, histopathology was used for further diagnosis in the serious patient. These patients were diagnosed with chloracne and separated from STCP. The patients were prescribed oral viaminate capsules, topical adapalene gel, and regular hematologic follow-up for aspartate transaminase and lipids. They are still under follow-up. There was no new lesions and the laboratory tests returned to normal in two patients. Pigmentation and shallow scars remained in the original areas of papules. However, in the most serious patient, new papules still appeared intermittently. All these remind us that the treatment of chloracne caused by STCP is difficult, and we should attach great importance to this new compound related with the neuropathy and chloracne.

CONCLUSION

STCP is becoming a new chemical product to induce chloracne, which should attract the attention of all medical professionals, especially dermatologists. Due to the lack of knowledge on the new chemical, the diagnosis of chloracne cannot be made in time. Chloracne still deserves our attention.

Dioxin-induced chloracne--reconstructing the cellular and molecular mechanisms of a classic environmental disease

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is among the most toxic pollutants known to date that serves as a prototype for a group of halogenated hydrocarbon compounds characterized by extraordinary environmental persistence and unique ability to concentrate in animal and human tissues. TCDD can elicit a complex array of pleiotropic adverse effects in humans, although chloracne, a specific type of acne-like skin disease, is the only consistent manifestation of dioxin intoxication, thus representing a 'hallmark' of TCDD exposure. Chloracne is considered to be one of the most specific and sensitive biomarkers of TCDD intoxication that allows clinical and epidemiological evaluation of exposure level at threshold doses. The specific cellular and molecular mechanisms involved in pathogenesis of chloracne are still unknown. In this review, we summarize the available clinical data on chloracne and recent progress in understanding the role of the dioxin-dependent pathway in the control of gene transcription and discuss molecular and cellular events potentially involved in chloracne pathogenesis. We propose that the dioxin-induced activation of skin stem cells and a shift in differentiation commitment of their progeny may represent a major mechanism of chloracne development.

Comedone formation: Etiology, clinical presentation, and treatment

An important feature in the etiology of acne is the presence of pilosebaceous ductal hypercornification, which can be seen histologically as microcomedones (Fig 1) and clinically as blackheads, whiteheads, and other forms of comedones, such as macrocomedones. There is a significant correlation between the severity of acne and the number and size of microcomedones (follicular casts), the presence of which is a measure of comedogenesis. This correlation can be demonstrated by skin surface biopsy using cyanoacrylate gel. In this procedure, microcomedones are sampled by applying cyanoacrylate gel to the skin surface. A glass microscopic slide is then applied on top of the gel and pressed firmly onto the skin for 1 minute(1-3). The glass slide is gently removed, taking with it the upper part of the stratum corneum and microcomedones, which are then analyzed by low-power microscopy or digital image analysis.(1-3)

Evaluation of topical anesthetics by laser-induced sensation: comparison of EMLA 5% cream and 40% lidocaine in an acid mantle ointment

BACKGROUND AND OBJECTIVE

Current techniques for assessing local anesthetics (e.g., pin-prick test) cannot elicit a specific afferent activity without contamination from mechanosensitive receptors. This study was aimed to validate the use of non-scarring laser pulses as a reproducible method to assess effectiveness of topical anesthetics by comparing EMLA 5% cream and 40% lidocaine ointment.

STUDY DESIGN/MATERIALS AND METHODS

Thirty-two evaluations per compound were achieved in a total of eight healthy subjects. Non-scarring pulses from a 585 nm Pulsed-dye laser and a double-frequency Nd:YAG laser were investigated as pain inducers and the results were statistically analyzed by using a Student t-test.

RESULTS

Discrimination of anesthesia was better assessed with the 1,064 nm Nd:YAG laser. Anesthesia obtained by EMLA 5% cream was significantly higher than for 40% lidocaine ointment (P <0.0001). For EMLA cream, the number of evaluations with complete anesthesia was twice as much as for 40% lidocaine.

CONCLUSIONS

Non-scarring laser pulses are reliable and reproductive pain inducers for assessing topical anesthetics showing a low intra-individual variation. This technique demonstrated that EMLA 5% cream is significantly more effective than 40% lidocaine ointment.

Comedogenesis: some new aetiological, clinical and therapeutic strategies

Hypercornification is an early feature of acne and precedes inflammation. It is associated with ductal hyperproliferation and there are many controlling factors such as androgens, retinoids and cytokines. Cycling of normal follicles and of comedones may explain the natural resolution of comedones and, in the longer term, resolution of the disease itself. There is a need to tailor treatment according to comedonal type. Suboptimal therapy can often result from inappropriate assessments of comedones, especially microcomedones, missed comedones, sandpaper comedones, submarine comedones and macrocomedones. Macrocomedones can produce devastating acne flares, particularly if patients are inappropriately prescribed oral isotretinoin. Gentle cautery under topical local anaesthesia is a useful therapy in the treatment of such lesions. The newer retinoids and new formulations of all-trans-retinoic acid show a better benefit/risk ratio. Evidence-based studies are required to allow adequate comparisons.

Blood lipid concentrations of dioxins and dibenzofurans causing chloracne

Chloracne is caused by exposure to certain halogenated polycyclic hydrocarbons such as polychlorinated dibenzodioxins (PCDDs) and dibenzofurans (PCDFs). In chronic exposure it is not known what level of intoxication, represented by the level in blood lipids, is sufficient to cause chloracne. Blood levels of the congeners of PCDD/Fs were determined in four groups of humans. One group had clinically visible chloracne due to exposure in a hexachlorobenzene workshop of a large chemical factory. A second group was exposed in the same workshop, but had no skin changes. There were two control groups: one non-exposed group of maintenance workers from the same chemical factory, and one group of healthy individuals living elsewhere. Blood levels were converted to toxicity equivalents of tetrachlorodibenzo-p-dioxin (TCDD). In the chloracne group blood levels in toxicity equivalents (TEQs) ranged from 1168 to 22,308 pg/g blood lipid. In the exposed without chloracne this ranged from 424 to 662 pg/g. It is concluded that the level to develop chloracne is between 650 and 1200 pg/g TEQ. The contribution of TCDD was rather small, and the main causative congeners were the hexachlorinated dibenzodioxins and dibenzofurans (HxCDD/Fs); lipid-based blood levels in absolute amounts that may cause chloracne are in the range of 2-3.5 ng/g HxCDD, and 2-5 ng/g HxCDF.

Severe halogen acne due to a trifluoromethylpyrazole derivative and its resistance to isotretinoin

We report a case of severe chloracne, with systemic involvement, following occupational exposure to dihydrotrifluoromethylphenyl benzothiopyranopyrazolone, which, to our knowledge, has not been previously reported as a cause of chloracne. Aggressive drug treatment, including high-dose oral isotretinoin was of limited benefit in suppressing the disease activity.