Nail cosmetology.

Nail cosmetics is enjoying growing success due to recent technological advances. Manicures can be responsible for mechanical, infectious or allergic adverse effects. Nail cosmetics (e.g., nail varnishes, acrylic false nails, light-curing gels, and adhesive false nails) incorporate substances that harden after solvent evaporation or after polymerization. Allergic reactions can occur, remotely with conventional varnishes and locally with polymerizing substances. Artificial nails incur a risk of carrying infectious agents which can cause serious infection, and should not be used by caregivers. Recently, there has been a worrisome increase in the frequency of acrylate allergy, due to the appearance of home kits and lack of information in the general public. The infectious, allergic and toxic risks incurred by consumers and professionals regarding manicure or pedicure treatments and the application of nail cosmetics are the subject of recommendations and monitoring measures.

Evolution of methylisothiazolinone sensitization: A Belgian multicentric study from 2014 to 2019.

BACKGROUND: In the 2010s an epidemic of allergic contact dermatitis to methylisothiazolinone (MI) occurred in Europe. European authorities banned the use of methylisothiazolinone in leave-on cosmetics in 2017 and limited its use in rinse-off products in 2018. OBJECTIVES: To investigate the sensitization rate to MI in Belgium between January 2014 and December 2019, and to assess cosensitizations to octylisothiazolinone (OIT) and benzisothiazolinone (BIT) in MI-sensitized patients. METHODS: A retrospective study of patch test results with MI, OIT, and BIT observed in patients attending five Belgian hospitals. RESULTS: Overall, 560 of 10 029 patients (5.58%) had a positive patch test reaction to MI, and its sensitization rate decreased from 7.9% in 2014 to 3.1% in 2019. Rinse-off cosmetics, paints, and detergents were the most prevalent sensitization sources in recent years. Simultaneous reactions readily occurred to OIT, and, surprisingly, and increasingly, also to BIT. CONCLUSIONS: Contact allergy to MI in Belgium has reached a pre-epidemic level, reflecting the impact of recent regulatory measures. Leave-on cosmetics, in contrast to rinse-off products, have almost disappeared as sensitization sources in Europe. Paints and detergents also remain problematic. The remarkably high number of patients (co)sensitized to BIT should be a focus of future research.

Hearing aid and Koebner phenomenon.

Koebner phenomenon may be related to frictions of a hearing aid on the external ear and retroauricular skin.

Refractory Trichophyton rubrum infection in lamellar ichthyosis.

A 10-month-old boy with congenital lamellar ichthyosis presented with a chronic Trichophyton rubrum infection. There was no history of atopy or immunosuppression, and examination revealed high total immunoglobulin E (IgE) with a positive specific IgE for T. rubrum. Multiple treatments with fluconazole were necessary to control the infection. T. rubrum is present worldwide and is responsible for the vast majority of chronic dermatophytosis. Lamellar ichthyosis is a risk factor for chronic dermatophytosis because of excessive keratin and the barrier defect. A delayed-type hypersensitivity reaction to T. rubrum is associated with cure, whereas immediate hypersensitivity and IgE are not protective and may lead to chronic infection. Atopy and the Th2 profile therefore seem to be associated with chronic dermatophytosis. The association between ichthyosis and atopy is well documented. T. rubrum also has an interesting ability to evade immunity, which helps explain the chronic infection. Finally, in ichthyosis, it is likely that fluconazole has difficulty penetrating the acanthotic stratum corneum, which explains treatment failure. We report this case to alert clinicians to the possible association between lamellar ichthyosis and chronic dermatophytosis and to report the difficulties of management.

POEMS syndrome revealed by multiple glomeruloid angiomas.

POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, skin disorders) is a rare multisystemic disease associated with plasma cell dyscrasia. A 68-year-old woman with chronic renal insufficiency and arterial hypertension included in her medical history was admitted to the hospital with confusion, somnolence and asthenia. She presented ascites, hepatosplenomegaly, leg oedema, distal dysesthesias, leuconychia and multiple nodular purple red angiomas on the trunk, upper limbs and fingers. Hypothyroidism was revealed in the laboratory investigations and monoclonal IgG peak in immunoelectrophoresis. Electromyography showed both demyelinisating and axonal degenerative neuropathy. The diagnosis of POEMS syndrome was based on the dermatopathological examination of a cutaneous angioma; histology revealed features of glomeruloid angioma, a specific marker of this syndrome.