The effect of methylprednisolone pulse therapy in polymyositis/dermatomyositis

Abstract

The study aim was to assess the effect of corticosteroid (CS) therapy on the clinical and biological features of dermatomyositis (DM) or polymyositis (PM). Material and Methods: 7 adult patients with severe or refractory DM/PM diagnosed according to Bohan and Peter criteria, who also had involvement of bulbar muscles, respiratory insufficiency, myocardial involvement and/or total loss of ambulatory capacity, were included in study. The pulse-therapy consisted into daily pulses of 0.5 g methylprednisolone, 3 consecutive days/month, for three months. The following parameters were recorded upon presentation, and at one and three months of therapy respectively: muscle strength on a 6-steps scale, presence and type of cutaneous involvement, creatinkinase (CK) and C-reactive protein (CRP) levels. Results: Muscle limb scores, as well as the CRP and CK levels, improved in all patients (with the notable exception of CK level in one patient). Amongst cutaneous features, Gottron's papules, vasculitis and mechanic's hands disappeared after the first pulse, while periungual erythema and poikiloderma were remarkably persistent even at the 3-months assessment. Amongst the extramuscular features of the disease, fever disappeared in all patients after the first pulse. Asymptomatic cardiac arrhythmia was present in one of the 2 patients, while interstitial lung disease was detected on x-ray in all the 4 patients involved. Conclusion: Methylprednisolone pulse therapy of DM/PM is an effective treatment. The persistence of cutaneous involvement does not imply an active disease. Therapeutic trials of the different subsets of inflammatory muscle disease are still needed.