Introduction Hydroxychloroquine is an antimalarial agent widely prescribed in internal medicine, rheumatology and dermatology. Its use can be complicated by various side effects including skin pigmentation. Objectives The aim of the study is to review epidemiological, clinical features and risk factors of hydroxychloroquine-induced pigmentation. Materials and methods We performed a cross-sectional study conducted over a period of 5 months. During this period, patients who had been treated with hydroxychloroquine for over 6 months, in the internal medicine department, underwent a complete dermatological examination. All patients completed a structured questionnaire to collect demographic data, dosage and treatment duration of hydroxychloroquine, other drug intake, hydroxychloroquine indication, and presence of pigmentary changes on the skin, nail, hair, and mucosa. Results A total of 41 patients (38 women and 3 men) were included in the study. The mean age was 39.2 ± 15.4 years. The hydroxychloroquine was indicated for systemic lupus erythematosus in 73.2%, dermatomyositis in 12.2%, rheumatoid arthritis in 9.8%, actinic lichen and sarcoidosis each in 2.4%. Cutaneous pigmented lesions were found in 21 cases (51%), mucous pigmentation in 5 cases (12%) and nail pigmentation in 1 case (2.5%). In 12 of 41 (29%) of the hydroxychloroquine users, we conclude a hydroxychloroquine-induced pigmentation. There were 11 women and one man with a mean age of 43 years and all of them were systemic lupus erythematosus patients. Pigmented lesions were located on the lower limbs in seven cases, the face in two cases, lips in two cases and the gum in two cases. Pigmentation appeared after a median duration of hydroxychloroquine treatment of 32 months with a median cumulative dose of 361 g. Overall, two patients reported that the appearance of pigmented lesions was preceded by the occurrence of ecchymotic areas following microtrauma. Significant association was found between hydroxychloroquine-induced pigmentation and treatment with oral anticoagulants and/or antiplatelet agents ( p = 0.03). Conclusion Our systematic examination of patients demonstrated that hydroxychloroquine-induced pigmentation is not rare. The imputability of hydroxychloroquine in the genesis of this discoloration is difficult to establish. Our study supports the hypothesis that ecchymosis, platelet antiaggregants and oral anticoagulants may be the main predisposing factors to hydroxychloroquine-induced pigmentation.

PH is characterized by the occurrence of exclusive skin lesions in young women with a good response to corticosteroids but not to Dapsone. Reactivity mainly against Dsg1 suggests that PH in south Tunisia is a particular variant of nonendemic pemphigus foliaceus.

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Pemphigus foliaceus (PF) is a rare autoimmune skin disease caused by anti-Dsg1 pathogenic autoantibodies. It is considered as a Th2-mediated disease. Likewise, Th17 cells were recently described in the pathogenesis of the disease but their role is still unclear. We aimed to unravel the eventual implication of the IL23/Th17 pathway in the development of PF. A case-control study was conducted on 115 PF patients and 201 healthy controls using PCR-RFLP and AS-PCR methods. SNPs in IL23R, RORγt, IL17A, IL17F, IL17AR, TNFa, and STAT3 genes were genotyped. mRNA expression of IL23R and RORγt was evaluated using Q-PCR. The frequency of circulating Th17 cells was analyzed by flow cytometry. Genetic associations between IL23R>rs11209026, IL17A>rs3748067, IL17F>rs763780, and TNFa>rs1800629 and the susceptibility to PF were reported. Moreover, we revealed a significant increased frequency of circulating CD4+IL17+ cells as well as higher mRNA levels of RORγt and IL23R in PBMCs of patients. However, no significant increase of RORγt and IL23R mRNA expression was observed in lesional skin biopsies. In spite of the little size of specimens, our results provide converging arguments for the contribution of the IL23/Th17 pathway in the pathogenesis of PF.

Background Hydroxychloroquine (HCQ)‐induced acute generalized exanthematous pustulosis (AGEP) is poorly described in the literature. The aim of our study was to characterize the clinical, laboratory, allergological, and genetic features of HCQ‐induced AGEP. Methods We conducted a retrospective study of patients with HCQ‐induced AGEP diagnosed between 2011 and 2019. We performed molecular analysis to identify variations in the IL36RN gene. We also reviewed similar cases reported between 1991 and March 2020. Results Seven female patients were included. The mean age was 47 years old, and the average time from HCQ start to onset of symptoms was 40 days. All patients received topical steroids with a full resolution of the rash within an average of 39 days after HCQ withdrawal. Patch tests were performed for three patients with positive results in one case. Genetic analyses were performed for three patients, and no mutation in the IL36RN gene was identified. Conclusion The latent period and the duration for resolution of HCQ‐induced AGEP may be longer than with other drugs due to the metabolic characteristics of HCQ. Mutations in the IL36RN gene were not identified in our patients.

Background Ichthyosis is a heterogeneous group of Mendelian cornification disorders that includes syndromic and non-syndromic forms. Autosomal Recessive Congenital Ichthyosis (ARCI) and Ichthyosis Linearis Circumflexa (ILC) belong to non-syndromic forms. Syndromic ichthyosis is rather a large group of heterogeneous diseases. Overlapping phenotypes and genotypes between these disorders is a major characteristic. Therefore, determining the specific genetic background for each form would be necessary. Methods A total of 11 Tunisian patients with non-syndromic (8 with ARCI and 2 with ILC) and autosomal syndromic ichthyosis (1 patient) were screened by a custom Agilent HaloPlex multi-gene panel and the segregation of causative mutations were analyzed in available family members. Results Clinical and molecular characterization, leading to genotype–phenotype correlation in 11 Tunisian patients was carried out. Overall, we identified 8 mutations in 5 genes. Thus, in patients with ARCI, we identified a novel (c.118T > C in NIPAL4) and 4 already reported mutations (c.534A > C in NIPAL4; c.788G > A and c.1042C > T in TGM1 and c.844C > T in CYP4F22). Yellowish severe keratoderma was found to be associated with NIPAL4 variations and brachydactyly to TGM1 mutations. Two novel variations (c.5898G > C and c.2855A > G in ABCA12) seemed to be features of ILC. Delexon13 in CERS3 was reported in a patient with syndromic ichthyosis. Conclusions Our study further extends the spectrum of mutations involved in ichthyosis as well as clinical features that could help directing genetic investigation.

Angiolymphoid hyperplasia with eosinophilia is a rare epithelioid vascular tumor with a challenging clinical and histological diagnosis. Despite its benign nature, ALHE causes a therapeutic dilemma.

Pemphigus foliaceus (PF) is a chronic autoimmune blistering skin disease characterized by acantholysis most likely associated with downstream events following the binding of desmoglein-1(Dsg1) specific IgG pathogenic auto-antibodies (-Abs) (Lee et al., 2009). PF develops as either sporadic disease occurring all over the world or in an endemic form. The latter is found mainly in South America and North Africa (especially in Tunisia) (Abida, Kallel-Sellami, et al., 2009; Bastuji-Garin et al., 1995). Pemphigus is associated with severe morbidity affecting the quality of life of young subjects and considerable mortality. Pemphigus therapies aim to improve symptoms by reducing serum autoantibodies, either directly or through generalized immune suppression