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.

The incidence of myositis in patients with systemic lupus erythematosus (SLE) is low among different series. Here we attempt to describe the main features of SLE/myositis overlap syndrome. We retrospectively reviewed the medical records of 174 patients with SLE seen over 15-year period. All the patients fulfilled the revised American Rheumatology Association criteria for SLE. Patients who met The Bohan and Peter criteria for definite myositis were included in this study. Among those patients, six patients had an associated myositis (3.4% overall). They were 6 women with a mean age of 29 years (20–41 years). At the initial evaluation, 3 patients (50%) were complained from myalgia, and all patients had symmetrical muscle weakness (proximal muscle weakness in 6 cases with distal muscle weakness in 2 cases). The muscle disease was severe in 1 case. Involvements of muscles of the pharynx and upper esophagus were noted in 4 patients (66.6%). The creatine kinase (CK) levels were elevated in 4 cases with a mean rate of 2153.5 UI/L. The electromyogram (EMG) revealed signs of myositis in 5 cases. Muscle biopsy, performed in 5 patients, revealed an inflammatory myopathy changes in 4 cases. Antinuclear antibodies (ANA) were positive in all cases. All our patients were treated with high doses of corticosteroids with favorable outcome. Relapse of SLE disease had occurred in 2 patients. The association SLE-myositis is rare with heterogeneous presentation. Through our observations and literature data we will specify the characteristics of this association.

The objective of the study was to investigate the association of caspase activating and recruitment domain 8 (CARD8) and nucleotide-binding oligomerization domain, leucine-rich repeat and pyrin domain containing 3 (NLRP3) polymorphisms with rheumatoid arthritis (RA) in Tunisian and French populations. CARD8 (c.30T>A, rs2043211) and NLRP3 (c.2113C>A, rs35829419) single nucleotide polymorphisms (SNPs) were genotyped in 100 French RA trio families and 141 Tunisian patients with RA and 191 unrelated healthy controls, using TaqMan(®) allelic discrimination assay. The genetic analyses for the association and linkage in French families were performed using the comparison of allelic frequencies (AFBAC), the genotype relative risk (GRR) and the transmission disequilibrium test (TDT). Data for case and control samples were analysed by chi-square-test, GRR and odds ratio (OR). No significant differences between alleles and genotypes frequencies were detected in French trio and Tunisian patients with RA and controls, either with CARD8 or with NLRP3 SNPs both in French and in Tunisian populations. Moreover, stratifying patients according to the presence of rheumatoid factor (RF), anti-cyclic peptides antibodies (ACPA), erosion, nodules, other autoimmune disease or HLA-DRB1*04-positive subgroups did not show any significant association with CARD8 or NLRP3 (P ≥ 0.05). This study suggests that variations in the innate immunity genes CARD8 (p.C10X) and NLRP3 (p.Q705K) have no effect on RA susceptibility either in the Tunisian or in the French population.

Our results, concerning North-African SLE patients, confirm the findings of previous studies which suggest that thrombocytopenia correlates with more severe disease and has a negative impact on the survival of lupus patients.