Respiratory failure in a patient with dermatomyositis

Since its original description in 1956 the association between interstitial lung disease and polymyositis (PM) and dermatomyositis (DM) has become well established. Interstitial lung disease (ILD) can be a significant complication in rheumatic diseases (RDs). Although most patients with RD do not develop clinically evident ILD, these systemic autoimmune disorders are estimated to be responsible for approximately 25% of all ILD deaths and 2% of deaths due to all respiratory causes. Radiologic abnormalities in DM are characterized by a high incidence of airspace consolidation. Non-Specific Interstitial Pneumonia (NSIP) is the most common form of lung disease, with a frequency in biopsies 4-fold greater than that of Usual Interstitial Pneumonia (UIP) in PM and a slightly smaller predominance in DM.

We report a case of a female patient, 57 years old, no former smoker, whose clinical history was onset in November 2008 with asthenia with muscle and osteoarticular pain especially located in the upper limbs and then also expanded to the lower limbs. The EMG was compatible with dermatomyositis in the acute phase. The patient received therapy with steroids and tacrolimus, also making several rounds of treatment with immunoglobulin. Given the recurrence of myositis in association with signs of poorly controlled interstitial lung disease, immunosuppressive therapy with Rituximab was administered. The Computed Tomography (CT) scans showed "bronchiectasis and traction bronchiolectasis, hypodense areas consistent with the phenomena of air trapping. The pattern of interstitial lung disease with fibrotic evolution seems consistent with NSIP.

The arterial blood gas analysis showed a pattern of hypoxic-hypercapnic respiratory failure (pH: 7,34, PaO₂: 67 mmHg; PaCO₂: 55 mmHg).

As a result of an episode of marked desaturation unresponsive to supplemental oxygen at high flows we proceeded to noninvasive mechanical ventilation with Helmet for 24 hours/24. This ventilatory support was maintained for a week, with resolution of the respiratory failure.

In this brief case report we want to highlight various pulmonary complications as a result of dermatomyositis. The progression of respiratory complications may also lead to a situation of respiratory failure, as in our patient, and require a noninvasive ventilatory treatment.