Photoaggravated allergic contact dermatitis and transient photosensitivity caused by methylisothiazolinone.

BACKGROUND: Photoaggravated allergic contact dermatitis caused by methylchloroisothiazolinone (MCI)/methylisothiazolinone (MI) and MI has been reported. OBJECTIVES: To describe the clinical characteristics and results of (photo)patch tests and photo-tests of 10 patients in Belgium and France suffering from photoaggravated contact dermatitis caused by MI. PATIENTS AND METHODS: Five men and five women, with a median age of 49.5 years, were investigated between January 2012 and February 2017 because of suspected photoaggravated contact dermatitis. Patch tests, photopatch tests and/or photo-tests were performed. RESULTS: Seven patients had positive patch test reactions to both MCI/MI and MI, whereas 3 patients had positive patch test reactions only to MI. In most cases, MI was the (strong) primary sensitizer. Photopatch tests with MCI/MI and/or MI gave stronger reactions than patch tests with these derivatives, indicating photoaggravation. Sensitization probably took place from cosmetics and work-related biocides, whereas elicitation of dermatitis was remarkably often related to airborne exposure to MI present in paints or industrial biocides. Four patients suffered from transient photosensitivity. CONCLUSION: Photoaggravated allergic contact dermatitis and transient photosensitivity caused by MI is a peculiar clinical presentation of allergic contact dermatitis caused by this preservative, and should be considered in daily clinical practice.

Exogenous inflammatory acne due to combined application of cosmetic and facial rubbing.

BACKGROUND: Exogenous acne refers to acneiform lesions due to external factors such as cosmetic agents, exposure to various oils, skin rubbing or friction or chloracne, now better called metabolizing acquired dioxin-induced skin hamartoma (MADISH). Here we report a new form of severe inflammatory exogenous acne due to the association of two factors: facial friction with cosmetic agents. OBSERVATIONS: A 15-, 17- and 19-year-old female presented at the department with severe inflammatory acne. In all cases, the face had been strongly rubbed in a compulsory manner in the previous weeks with cosmetic agents. The disease has not responded to various conventional acne treatments and was well controlled by a combination of oral corticosteroids and low-dose isotretinoin. CONCLUSION: Because cosmetic face friction as a cosmetic care becomes more and more fashionable, dermatologists should be aware of this severe clinical condition, which can occur in patients without a personal history of acne.

Clinical phenotype of scabies by age.

OBJECTIVE: Scabies has a clinical presentation that seems to vary according to age. We conducted a prospective study with the goal of delineating the clinical presentation of the disease into 3 groups of age: infants, <2 years; children, 2 to 15 years; and adults, >15 years. METHODS: This trial was a prospective, multicenter observational study in consecutive patients with a confirmed diagnosis of scabies who were seen in 13 French Departments of Dermatology and Pediatric Dermatology between April 2010 and April 2011. A standardized questionnaire was completed for each patient. To identify factors associated with patient age, comparisons between the 3 age groups were conducted by using univariate and multivariate multinomial logistic regression analyses. RESULTS: A total of 323 individuals were included; the gender ratio (female:male) was 1.2:1. In univariate analysis, infants were more likely to have facial involvement. In multivariate logistic regression, relapse was more frequent in children (odds ratio [OR]: 2.45 [95% confidence interval (CI):1.23-4.88]) and infants (OR: 3.26 [95% CI: 1.38-7.71]). In addition, family members with itch (OR: 2.47 [95% CI: 1.04-5.89]), plantar (OR: 20.57 [95% CI: 7.22-58.60]), and scalp (OR: 16.94 [95% CI: 3.70-77.51]) involvement were also found to be independently associated with the age group <2 years. CONCLUSIONS: There is a specific clinical presentation of scabies in infants and children. Taking into account these specificities may be helpful for the early diagnosis and the identification of cases to prevent the propagation of the disease.

Tumor homogeneity between primary and metastatic sites for BRAF status in metastatic melanoma determined by immunohistochemical and molecular testing.

BRAF inhibitors have demonstrated improvement of overall survival in patients with metastatic melanoma and BRAF(V600) mutations. In order to evaluate BRAF tumor heterogeneity between primary and metastatic site, we have evaluated the performance of immunohistochemistry (IHC) with an anti-BRAF(V600E) antibody in both localization by comparison with high resolution melting analysis followed by Sanger sequencing in a parallel blinded study. A total of 230 samples distributed as primary melanoma (n = 88) and different types of metastatic samples (n = 142) were studied in 99 patients with advanced or metastatic melanoma (stage III or IV). The prevalence of each BRAF mutation was c.1799T>A, BRAF(V600E) (45.2%), c.1799_1800TG>AA, BRAF(V600E2) (3.0%), c.1798_1799GT>AA, BRAF(V600K) (3.0%), c.1801 A>G, BRAF(K601E) (1.3%), c.1789_1790CT>TC, BRAF(L597S) (0.4%), c.1780G>A, BRAF(D594N) (0.9%) respectively. IHC was positive in 109/112 samples harboring BRAF(V600E/E2) mutations and negative in other cases. The cytoplasmic staining was either strongly positive in tumor cells of BRAF(V600E) mutated cases. It appeared strong brown, different from the vesicular grey cytoplasmic pigmentation of melanophages. Concordance between the two techniques was 96.4%. Sensitivity of IHC for detecting the BRAF(V600E/E2) mutations was 97.3%, while specificity was 100%. Both our IHC and molecular study demonstrated homogeneity between primary and metastatic sites for BRAF status in melanoma. This study also provides evidence that IHC may be a cost-effective first-line method for BRAF(V600E) detection. Thereafter, molecular techniques should be used in negative, ambiguous or non-contributive cases.