ABSTRACT
Introduction: Dermatomyositis is a rare idiopathic inflammatory myopathy with distinctive cutaneous manifestations. This study aims to determine the demographic characteristics, clinical features and associated malignancies in patients with dermatomyositis. Materials & Methods: Dermatomyositis is a rare idiopathic inflammatory myopathy with distinctive cutaneous manifestations. This study aims to determine the demographic characteristics, clinical features and associated malignancies in patients with dermatomyositis. Results: Forty-three cases were identified, with female to male ratio of 1.26:1. Mean age of onset was 47.8 +18.0 years. Malay and Chinese patients made up the bulk of the patients, contributing 53.5% and 44.2% respectively. Photosensitive rash was the commonest clinical presentation, occurring in 55.8% of the patients, followed by Gottron’s papules (46.5%), heliotrope rash (44.2%), alopecia (23.3%) and calcinosis (9.3%). Median Creatinine Kinase level was 293IU/L (interquartile range 89-1166), Lactate Dehydrogenase 641IU/L (interquartile range 459-986) and Aspartate Transaminase 70.5IU/L (interquartile range 41.5-156.25). Concomitant malignancies occurred in 14 patients (32.5%), the commonest being nasopharyngeal carcinoma (6 patients), followed by gastrointestinal tumours (3 patients), breast cancer (2 patients) and lymphoproliferative disorders (2 patients) and lung cancer (1 patient). Of these 14 patients, malignancies were detected in 10 patients within the first year, and 2 patients within the second year after diagnosis of DM. Two patients had malignancies diagnosed within 6 months prior to the diagnosis of DM. Malignancy accounts for 64.7% of the 17 mortalities recorded. The proportion of Malay patients with paraneoplastic dermatomyositis with respect to the total number of Malay new clinic attendees over the past 13 years is 7 in 10,000 persons whereas in Chinese patients, the proportion is 15 in 10,000 persons. Conclusion: Malignancy is found in about a third of all patients, with Chinese predisposition seen. This could explain why nasopharyngeal carcinoma is most prevalent in our centre.