Dermatomyositis is a collagen tissue disease that is caracterized by a double muscular and cutaneous involvement  . Its course is chronic with numerous complications. It is a rare disease with severe prognosis. It is the third collagen tissue disease after lupus erythematous and scleroderma. The prevalence of this condition varies from one part of the earth to another  . The clinical aspects are numerous in the literature. At the Therapeutical level, their management uses currently first-line corticosteroid therapy  . Few studies have been devoted to this disease in sub-Saharan Africa. It was therefore appropriate for us to conduct this study at the department of Dermatology-Venerology of the University Hospital Centre of Treichville in order to describe the epidemiological and clinical characteristics and to indicate the therapeutic and evolutive aspects of this disease in black African, in Cote d’Ivoire.
2. Material and Methods
This is a retrospective descriptive and analytical study carried out in the Dermatology Department of the University Hospital Center of Treichville over a 10-year period from January 2006 to December 2015. Have been taken into account and included in the study, all patients hospitalized for dermatomyositis whose diagnosis was retained on the criteria of Bohan and Peter using clinical signs such as cutaneous and muscular involvement and biological signs especially the muscular enzyme. The study was approved by the ethic committee of the hospital. Data from the study were collected on a survey card that included socio-demographic characteristics and clinical data such as circumstances of discovery; cutaneous and muscular involvement, post-inflammatory disorders, others extra-cutaneous manifestations, biological disorders, therapeutic and evolutive aspects. The data was entered and analysed using Microsoft® Excel® 2010 software version 14.0.4760.1000. As for the analysis of the data, it was made using the software Epi Info 6.4d.
Limitations of the study
This is a retrospective study that does not allow us to have all the variables in all patients. In the files some cutaneous lesions were not well described, biological examinations could not be carried out in some patients and the follow-up was difficult sometimes because patients did not always respect their Appointment.
3.1. At the Epidemiological Level
We accounted 37 cases of dermatomyositis on 2674 hospitalized patients during this period with a hospital prevalence of 1.38%. The age of our patients ranged from 11 to 79 years with an average of 41 years. There was a female predominance with a sex ratio of 0.48.
3.2. At the Clinical Level
The delay before the first consultation ranged from 1 week to 1 year 9 months with an average of 5 months. The circumstances of discovery of the disease were cutaneous (62.16%), muscular (18.91%), articular (10.81%) or after a long-term fever (13.51%). The cutaneous signs were dominated by post-inflammatory hyperpigmentation and erythro-oedema (Table 1). The muscular manifestations were mainly represented by muscular pain (Table 2). Other extra-cutaneous signs were dominated by general condition impairment (86.47%) and fever (48.65%). Some pathologies were associated with dermatomyositis such as vitiligo (2 cases), viral hepatitis B (2 cases), diabetes (3 cases) and hypertyroidie (1 case).
3.3. The Paraclinical Aspects
At the Biological level, the rate of muscle enzymes including lactic-dehydrogenase (LDH) and Creatin phosphokinase (CPK) were high respectively in 78.38% and 54.05% of cases. The immunological examinations could not be carried out in the majority of the patients because of the financial difficulties. The antibodies anti Jo1, anti -SM and anti-U1-RNP were positive respectively in, 2; 6 and 5 patients. The electromyogram performed in 70.27% of cases showed a myogenic pattern in favor of the diagnosis. The electrocardiogram showed left ventricular hypertrophy in 10 patients, sinus tachycardia in 6 patients and coronary syndrome in 6 other patients. The chest scanner showed interstitial syndrome in 3 cases, pulmonary fibrosis in 2 cases and fluid pleural effusion in 4 patients. Oeso-gastroduodenal fibroscopy revealed 2 malignant tumors of the stomach.
Table 1. Distribution according to cutaneous lesions.
Table 2. Distribution according to muscle signs.
3.4. At the Therapeutic and Evolutive Aspects
The duration of hospitalization was 3 weeks on average. Oral corticosteroids were administered to almost all patients (94.59%). In 16.22% of cases corticosteroids were associated with methotrexate and in 37.84% with hydroxychloroquine. Physical therapy was prescribed in 12 patients. The minimum duration of follow-up was 2 months and the maximum duration was 2 years. Clinical improvement was observed 2 months after initiation of treatment in 18.92% of cases and 4 months after initiation of treatment in 70.27% of cases. Side effects observed during treatment were diabetes (3 cases) and hypertension (2 cases). 64.86% of patients had infectious complications. The death rate was 16.22%.
Only 37 cases of dermatomyositis were reported in 10 years with a hospital prevalence of 1.38%. It is therefore a rare pathology in Côte d’Ivoire. Our patients were mostly young women with an average age of 41 years. Our results agree with some studies in sub-Saharan Africa   . The average time of diagnosis was 5 months. It could be explained by the therapeutic itinerary of patients in Africa who are very often engaged in traditional therapy and self-medication  . Clinically, the signs of this disease are sometimes polymorphic, but cutaneous involvement is usually the first manifestation showing off as post-inflammatory hyperpigmentation and erytho-oedema, hence the importance of the dermatologist in the early detection of this disease  . Muscular deficiency was also a persistent sign, but we did not observe diffuse cutaneous calcinosis reported by some authors   . Dermatomyositis is a connective tissue disease that can be associated with other pathologies such as neoplasia  . Some radiological examinations are therefore necessary including fibroscopy which allowed us to diagnose 2 stomach cancers in our patients. Biological examinations have revealed the increase of the rate of muscular enzymes as key elements in the diagnosis of this condition  . At the Therapeutical level, monotherapy with oral corticosteroids was instituted in 93.75% of our patients. It lead to a clinical improvement 4 months after treatment on average. To minimize the adverse effects of this long-term corticosteroid therapy, some authors recommend combining immunosuppressive with synthetic antimalarials  . We used this combination method in 6.25% of our patients. The death rate after one year of follow up was 6.25%. In the literature, death rates is very variable ranging from 5% to 70%  . Late management, visceral involvement, iatrogenic complications and the association with a neoplasia are factors of poor prognosis for this disease  .
Dermatomyositis is a rare disease in Cote d’ivoire. It involves mostly the young adult with a slight feminine predominance. It is a serious pathology of severe prognosis even if the corticotherapy makes it possible to control the disease. The cutaneous manifestations are the first signs of this affection, hence the importance of the dermatologist in his screening and his early management.
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