Background Juvenile Dermatomyositis (JDM) is a rare, autoimmune condition of childhood which primarily involves the skin and muscles but can affect many organ systems due to widespread vasculopathy. The incidence in the UK is 1.9 per million children under the age of 16 years (1). Although the aetiology of JDM remains unclear, a combination of genetic and environmental triggers have been proposed as causative factors in individuals with JDM.
Calcinosis is a well recognised complication of JDM affecting between 20-40% of patients (2). It tends to develop in those with a longer duration of active disease, usually related to delayed diagnosis or inadequate treatment (3). Calcinosis is a major cause of morbidity in children with JDM causing pain, cosmetic disfigurement, reduced physical function and decreased quality of life. Commonly affected sites include the elbows, knees and extremities.
Anecdotal reports, with pamidronate, infliximab, probenicid, and diltiazem show success in limiting the rate of calcinosis (2). However, treatment for calcinosis remains notoriously challenging. Surgical excision is reserved for cases where pressure effects or disfigurement are present.
There is limited information in the literature about the use of rituximab, an anti-CD20 monoclonal antibody which targets B cells, in JDM. One series suggests rituximab may be effective in treating muscle and skin involvement in a small subset of children with severe JDM (4). A randomised trial of rituximab for patients with JDM is currently being proposed in the UK.
Objectives We report the case of a 9-year-old boy with Juvenile Dermatomyositis (JDM) and widespread calcinosis who has developed marked dysphonia, 6 years after initial diagnosis. The case highlights the difficulties with the management of this complication of JDM.
Methods Our patient had been previously managed with immunosuppressive agents including methotrexate, infliximab and adalimumab. Biologic treatment was not tolerated. Maintenance therapy has been with long-term oral steroids. Clinically there is superficial calcinosis in the midline of the neck. Progressive dysphonia has necessitated investigation for cricothyroid cartilage and recurrent laryngeal nerve involvement. With the progressive calcinosis and ongoing muscle inflammation, rituximab therapy (with cyclophosphamide) has commenced.
Results We will present the effects of rituximab treatment on his clinical condition.
Conclusions Calcinosis is a well recognised complication of JDM which is notoriously difficult to treat. We present the results of the nouvelle use of rituximab in a patient with extensive calcinosis.
Symmons DP, Sills JA, Davis SM. The incidence of juvenile dermatomyositis: results from a nation-wide study. Br J Rheumatol. Aug 1995;34(8):732-6
Rider LG. Calcinosis in juvenile dermatomyositis: pathogenesis and current therapies. Pediatric Rheumatology Online Journal. 2003; 1(2): 119-133
Fisler RE, Liang MG, Fuhlbrigge RC, et al. Aggressive management of juvenile dermatomyositis results in improved outcome and decreased incidence of calcinosis. J Am Acad Dermatol 2002; 47:505-11
Bader-Meunier B, Decaluwe H, Barnerias C, et al. Safety and Efficacy of Rituximab in Severe Juvenile Dermatomyositis: Results from 9 Patients from the French Autoimmunity and Rituximab Registry. J Rheumatol. 2011 Jul; 38(7):1436-1440
Disclosure of Interest None Declared