294 Inverse Gottron papulesin dermatomyositis: report of four paediatric cases and review of literature

Abstract

Background: Juvenile dermatomyositis (JDM) is the most common inflammatory myopathy in children. Gottron papule is a pathognomonic cutaneous sign of JDM. Gottron papule over palmar surface has rarely been reported in children. Methods: We undertook a retrospective review of children with JDM who had inverse Gottron papules and a completed a brief review of literature. Results: Four patients (all females and ≤ 10 years) were found to have inverse Gottron papules. Muscle weakness was noted in three children while one child presented with prominent cutaneous signs only. Two children had features of overlap (one with systemic scleroderma and one localised scleroderma). Inverse Gottron papules were noted over proximal and interphalangeal joints (palmar and lateral aspect) as well as over palms. Muscle enzymes were found to be elevated in all children and three children had evidence of myositis on magnetic resonance imaging. Anti-nuclear antibody was positive in two children (both nucleolar pattern). Immunoblot revealed anti U1RNP antibody, anti Pm/scl antibody and anti Ro antibody in one patient each. Pulmonary function test was normal in three while one patient showed mild restriction. High resolution computed tomography (HRCT) chest showed changes of interstitial lung disease in three patients. Treatment included prednisolone in all four, methotrexate in three, cyclophosphamide in one and azathioprine in two. All children are on follow-up (follow-up period of four months to four years). Muscle weakness has resolved in all children. Disease relapse was noted in in one child and she responded well to re-treatment. A review of all reported cases of palmar Gottron papules in JDM revealed a total of 42 cases in adults and only three cases in children. The morphology of inverse Gottron papules was found to be similar to previously reported cases in the literature i.e. flat white topped papules, occasionally triangular shaped, mostly in the creases of interphalangeal joints and occasionally in the palmar crease as well. In addition, one patient was also noted to have Gottron papules on radial aspect of index fingers, a unique finding that has never been reported before. An association between palmar Gottron papules with anti MDA-5 (melanoma differentiation associated gene-5) antibody positivity and interstitial lung disease is seen in many adult studies. In this study, 2/4 children had ANA positivity and 3/4 children had changes of ILD. Conclusion: Palmar Gottron papules has rarely been reported in children with JDM and are associated with increased risk on ILD.