Isothiazolinones in cleaning products: Analysis with liquid chromatography tandem mass spectrometry of samples from sensitized patients and market.

BACKGROUND: Methylchloroisothiazolinone (MCI) and methylisothiazolinone (MI) contact dermatitis is a severe problem. The high concentrations of these substances and other isothiazolinones such as benzisothiazolinone (BIT) and octylisothiazolinone (OIT) contained in cleaning products may cause allergic contact dermatitis in sensitized patients. OBJECTIVES: To evaluate the exposure to isothiazolinones contained in cleaning products on the market and from sensitized patients, and to verify the accuracy of labeling. METHODS: A total of 34 cleaning products were collected (17 supplied by sensitized patients and 17 bought randomly). Analysis was made of the concentrations of MI, MCI, BIT, and OIT using liquid chromatography tandem mass spectrometry (LC-MS/MS). RESULTS: MI and BIT were the components most frequently detected. Of all the products analyzed, 76.5% contained at least one isothiazolinone. Twelve products had an MI concentration above the permitted level for rinse-off cosmetics. Most of them were coming into direct contact with the skin in daily use. Mislabeling occurred in eight products. CONCLUSIONS: Some cleaning products with high concentrations of isothiazolinones may cause cutaneous symptoms in sensitized patients, especially in spray form. The labeling should be correct, also regarding the use of each article.

Primary Cutaneous Diffuse Large B-Cell Lymphoma, Leg Type, With Spontaneous Regression After Biopsy.

Primary cutaneous diffuse large B-cell lymphoma, leg type (PCDLBCL-LT) represents approximately 20% of cutaneous B lymphomas with an intermediate prognosis. Spontaneous regression is uncommon; there are only 2 published cases. An 83-year-old woman presented 2 orange erythematous nodules on the back of her right leg with an elastic consistency, infiltrated, painful to the touch, and of an 8-month evolution. A histological examination revealed a dense cellular dermo-hypodermic infiltrate sparing the papillary dermis, composed of large cells with immunoblast and centroblast morphology and frequent mitosis. Immunohistochemical studies showed positivity for CD20, CD79, Bcl2, Bcl6, MUM1, Fox-P1, and IgM with Ki67 >95%. Rearrangement of heavy IgH chains was monoclonal. The extension study was negative, establishing a diagnosis of PCDLBCL-LT, T2aN0M0. Three months after biopsy, the patient's lesions regressed spontaneously. New biopsies were taken that revealed a mild diffused dermo-hypodermic cellular infiltrate compounded by small-sized T lymphocytes, with predominance of CD8. Despite its self-limited character, treatment with radiotherapy was done, remaining asymptomatic after 1 year follow-up. There are 2 published cases of PCDLBCL-LT with spontaneous regression. The cause of this unusual autoinvolutional phenomenon is unknown; it may be an immune response against tumor cells through a traumatic or infectious mechanism.

Cutaneous Mastocytosis With Atypical Mast Cells in a 7-Year-Old Girl.

Cutaneous mastocytosis is defined by the presence of mast cells within the skin in the absence of other criteria for the diagnosis of systemic mastocytosis. Mast cells are characterized by an abundant granular cytoplasm and a round to oval or spindle-shaped nuclei. The presence of mast cells with bilobed and multilobed nuclei in cutaneous mastocytosis is a rare phenomenon and has been rarely reported in the literature. To our knowledge, there are only 4 reported cases of cutaneous mastocytosis with atypical mast cells. We hereby report a case of urticaria pigmentosa in a 7-year-old female patient. The patient presented with asymptomatic skin lesions of several years duration over the neck and left scapular area. Histopathological examination revealed the presence of middermal perivascular infiltrates mainly composed of mast cells, few lymphocytes, and eosinophils. Most mast cells showed pleomorphic nuclei with bilobed and multilobed morphology that revealed a positive expression for CD117, tryptase, CD68, and Giemsa stains. Based on these findings the diagnosis of urticaria pigmentosa with atypical mast cells was made. Additional tests to rule out systemic involvement were performed. All values, including a tryptase level, were within normal limits. No changes were noted after 1-year follow-up.

Persistence of Isothiazolinones in Clothes After Machine Washing.

BACKGROUND: Sensitization to methylchloroisothiazolinone (MCI) and methylisothiazolinone (MI) is a worldwide problem. Washing machine detergents are suspected to cause cutaneous symptoms in highly sensitized patients. Little is known about the persistence of isothiazolinones in clothes that have been washed. OBJECTIVE: The aim of the study was to analyze the possible persistence of MI, MCI, benzisothiazolinone, and octylisothiazolinone in common fabrics after machine washing. METHODS: Different clothes (cotton, polyester, linen, and wool) were collected, and 4 types of wash were done (control, standard, standard + conditioner, and standard + double rinse). The samples were analyzed using ultrahigh-performance liquid chromatography. RESULTS: The results showed that the concentrations of isothiazolinones were very low, independent of the type of material or wash. The highest levels were found in the control wash (hand wash), reaching a maximum of 0.4 ppm in the linen. CONCLUSIONS: Our findings suggest that it is not necessary to recommend that patients sensitized to MI avoid isothiazolinones in machine detergents or fabric conditioners or to double rinse. However, after using the detergent for hand washing (the control in our study), there may remain sufficient concentrations of isothiazolinones in clothes to produce symptoms in highly sensitized patients.

The Role of Cleaning Products in Epidemic Allergic Contact Dermatitis to Methylchloroisothiazolinone/Methylisothiazolinone.

BACKGROUND: Sensitivity to methylchloroisothiazolinone (MCI)/methylisothiazolinone (MI) has increased rapidly over recent years. This increase is mainly related to the extensive use of high concentrations of MI in cosmetic products, although a growing number of cases of occupational allergic contact dermatitis are caused by MCI/MI. OBJECTIVE: The aim of this study was to examine the association between the increase in MCI/MI sensitization and the work performed by the patients in our area. METHODS: A retrospective study was undertaken of the records of a total of 1179 patients who had undergone contact skin patch tests for MCI/MI from January 2005 to December 2015. A multivariate logistic regression analysis was performed to identify the factors independently associated with sensitivity to MCI/MI. RESULTS: A constant increase in MCI/MI sensitization was observed over the observation period. The only work associated with a significant increase in the prevalence of MCI/MI sensitization was cleaning, with 38.5% of the cleaning professionals with MCI/MI sensitization consulting for cosmetics-related dermatitis. CONCLUSIONS: Occupational sensitization to MCI/MI in cleaning professionals is worryingly increasing. This, in turn, could possibly account for many cases of cosmetics-associated contact dermatitis. Our findings suggest that a review of the regulations with regard to isothiazolinone concentrations in industrial and household detergents is necessary.