Vitiligo is a chronic autoimmune depigmenting skin disorder that results from a loss of melanocytes. Multiple combinatorial factors have been involved in disease development, with a prominent role of the immune system, in particular T cells. After repigmentation, vitiligo frequently recurs in the same area, suggesting that vitiligo could involve the presence of resident memory T cells (T). We sought to perform a thorough characterization of the phenotype and function of skin memory T cells in vitiligo. We show that stable and active vitiligo perilesional skin is enriched with a population of CD8 T expressing both CD69 and CD103 compared with psoriasis and control unaffected skin. CD8 T expressing CD103 are mainly localized in the epidermis. Expression of CXCR3 is observed on most CD8 T in vitiligo, including the population of melanocyte-specific CD8 T cells. CD8 T displayed increased production of IFN-γ and tumor necrosis factor-α with moderate cytotoxic activity. Our study highlights the presence of functional CD8 T in both stable and active vitiligo, reinforcing the concept of vitiligo as an immune memory skin disease. The CD8 T that remain in stable disease could play a role during disease flares, emphasizing the interest in targeting this cell subset in vitiligo.

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Background: Biomarkers of disease activity/severity and criteria of autoimmune chronic spontaneous urticaria (CSU) are still a matter of debate. Objective: To investigate possible correlations between clinical and biological markers and their associations with: (i) disease activity; (ii) resistance to H1-antihistamines; (iii) autoimmunity; and (iiii) autologous serum skin test (ASST) in patients with CSU. To also analyze biological parameter modifications in patients with CSU treated with omalizumab. Materials and methods: Disease activity, H1-antihistamines response and presence of concomitant autoimmune disease were prospectively recorded in 95 patients with CSU. For 60 of them, ASST was performed. Broad biological analysis were performed. Results: C-reactive protein (CRP) serum levels were higher in H1-antihistamines unresponders (p<0.0001) and in more active diseases (p=0.033). D-dimer plasma levels were higher in H1antihistamines unresponders (p=0.008) and in patients with autoimmune status (concomitant autoimmune disease and/or with autoantibodies) (p=0.016). Total immunoglobuline E (IgE) serum level was lower in patients with positive ASST. Blood basophil counts were lower in patients with CSU and especially in H1-antihistamines unresponders (p=0.023), in patients with more active disease (p=0.023), with positive ASST (p=0.001), and with autoimmune status (p=0.057). Conversely, under omalizumab, a decrease of CRP (p=0.0038) and D-dimer serum/plasma levels (p=0.0002) and an increase of blood basophil counts (p=0.0023) and total IgE serum levels (p=0.0007) were observed. Conclusions: This study brings additional evidences of interest to investigate IgE, D-dimer serum/plasma levels and basophil blood counts in patients with CSU as they could be correlated to disease activity, response to treatment and/or autoimmunity.

These small case series confirm that both chlorhexidine and benzalkonium chloride are implicated in contact dermatitis from antiseptic use in the paediatric population. We emphasize the initial misdiagnose of these patients, the very young age of the children and the allergenic potential of common antiseptics in non-atopic children. We hypothesize that the systematic use of antiseptics for umbilical cord care could be responsible for the sensitization in newborns.

K E Y W O R D S : aluminium, children, contact allergy, vaccine Persistent itching subcutaneous nodules at the injection sites of aluminium-adsorbed vaccines are increasingly described in children and are associated with contact allergy to aluminium, in 77% to 100% of cases, according to different studies. 1-3 In general, aluminium is considered to be a rare allergen, given its wide usage and the relative scarcity of contact dermatitis cases. However, the prevalence of contact sensitization to aluminium in children is not well known. The objective of this study was to determine the prevalence of contact sensitization to aluminium in a paediatric population consulting for patch testing in a French paediatric dermatology department, and to study the association of the sensitization with persistent itching nodules. METHODS Metallic aluminium (empty Finn Chamber; SmartPractice, Phoenix, Arizona) and aluminium chloride hexahydrate 2% pet. (Chemotechnique Diagnostics, Vellinge, Sweden) had been systematically added to the patch test series for children. From July 2014 to December 2017, 97 patients patch tested for suspected contact allergy were thereby tested with aluminium. The test was applied on the backs of the children, removed on day (D) 2, and read by an experienced allergologist/ dermatologist on D2 and D3 according to ICDRG recommendations.Beyond D3, later readings were made daily by the parents, who had been told to look for a late reaction.