Juvenile dermatomyositis in South African children is characterised by frequent dystropic calcification: a cross sectional study

Abstract

BackgroundTo describe Juvenile dermatomyositis (JDM) that has rarely been reported in Sub-Saharan Africa in children.MethodsRetrospective record review of children with JDM attending a tertiary hospital in South Africa.ResultsTwenty-one children (16 female, five male) with JDM had a mean (SD) age at presentation of 9.8 (3.3) years. Mean follow-up period was 2.6 (2.2) years. The commonest presenting features were skin rash (71%), muscle weakness (71%), inflammatory arthritis (42%) and calcinosis (29%). The cumulative frequency of calcinosis was 71%. Skin vasculitis was present in 9(43%), and 7 (33%) had Staphylococcus aureus infections. Calcinosis was strongly associated with vasculitis; 11/15 (73.3%) with calcinosis had vasculitis versus 0/6 without vasculitis (p = 0.003). Patients with calcinosis had significantly lower creatinine kinase (CK) levels compared to those without calcinosis [mean (SD) 272 U/L (401) vs. 2414 U/L (3201), respectively, p = 0.016]. All children with calcinosis had Staphylococcus aureus infection, but there was no significant difference in their duration of symptoms to presentation. Joint contractures, occurring in eight patients (38%), were associated with a significantly lower age at presentation [mean (SD) 6.8(2.8) vs. 11.6(2.1) years (no contractures) p = 0.0003], and significantly higher CRP and ESR levels. Three patients were lost to follow-up, two died. In the remaining 16 patients: 10 (47%) experienced remission, 2 relapsed and 4 persistent active disease.ConclusionAfrican children with JDM have increased vasculitic disease and high levels of calcinosis with low muscle enzymes, particularly CK. Younger children are at higher risk of contractures and disability. Patients are at high risk of developing Staphylococcus aureus infection. Rapid and aggressive therapy is necessary.

Characteristics and outcome of children with juvenile dermatomyositis in Cape Town: a cross-sectional study

“…This finding was consistent with that by Faller et al [9] who reported a mortality of 9.5 % (1 death per 27.3 patient years) among indigenous African children with JDM from Johannesburg, South Africa. These two studies were small and it’s not possible to draw generalizable conclusions.…”

“…Mendez et al reported a lower incidence rate among children of Hispanic ancestry compared to those of African and Caucasian ancestry in the USA [14]. Racial differences have also been noted in the incidence rates of certain disease manifestations with much higher incidence of calcinosis being reported among children of African ancestry compared to other racial groups [9, 15, 16]. …”

“…Despite the improvement in mortality rates among JDM patients, disease and treatment related damage remains a major challenge and significantly affect the quality of life of affected individuals. However, data on the characteristics and treatment outcome of JDM patients from Africa is scarce and only one study has been published that specifically described a series of JDM patients from the continent [9]. In that study, a higher rate of calcinosis and vasculitis compared to that from other regions was reported suggesting that the clinical manifestations and outcome of JDM in African patients could be different.…”

The Presentation, Assessment, Pathogenesis, and Treatment of Calcinosis in Juvenile Dermatomyositis

“…Another multicenter registry has described an association of calcinosis with African American race, even after adjustment for duration of disease and time to rheumatologic care [37]. Similarly, it was reported that African children with JDM have increased vasculitic disease and a high frequency of calcinosis, even with lower serum muscle enzyme levels [38]. In a JDM cohort from the UK, calcinosis was associated with younger age of disease onset [29].…”

Extensive Calcinosis in an Adult Nigerian Woman with Dermatomyositis

“…Diagnosis is based on the Bohan and Peter classification criteria [1] . DM is mostly seen in children, with few reports of this condition among African children [2,3] or adult black Africans [4] , but with some studies among adult African Americans [5,6,7] . Calcinosis while often reported in children [3] is rarely associated with adult DM cases, which are mostly described in case reports [5,8,9,10] .…”