ABSTRACT: Background:The syndrome of drug reaction with eosinophilia and systemic symptoms (DRESS) is a rare, yet potentially fatal hypersensitivity reaction, most commonly associated with anticonvulsants, sulfonamides, and allopurinol. The reaction commonly manifests as a febrile skin eruption with lymphadenopathy and malaise between two and eight weeks following drug exposure. Internal organ involvement occurs in close to 90 percent of patients, and multiple organs may be involved in approximately half of those affected (most commonly the liver, kidney, and lung). Its long latency period and its variable clinical pattern of presentation have earned it the moniker of "the great mimicker," with delays in diagnosis leading to higher morbidity and mortality. Although less commonly affected in DRESS syndrome, lung involvement is associated with more severe clinical course and potentially worse outcome. Pulmonary symptoms may precede development of the other more common symptoms and signs of the syndrome, or they might develop later in the course of the disease. Lung involvement in DRESS presents with a plethora of manifestations from mild cough or dyspnea with nonspecific interstitial changes on chest imaging to acute respiratory distress syndrome (ARDS) with life-threatening hypoxic respiratory failure. Methods:We performed a systematic review of literature from the PubMed database and selected cases of definite DRESS syndrome as defined by the European Registry of Severe Cutaneous Adverse Reactions (RegiSCAR) with a score of 6 or more who also had pulmonary involvement. Demographic data, pattern of lung involvement, culprit medication, latency period, laboratory findings, therapy, and outcome were described and compared with the literature. Results:The most common pulmonary radiographic findings in DRESS were interstitial infiltrates in 50% of cases, followed by acute respiratory distress syndrome (ARDS) 31%. Symptoms of cough and shortness of breath (SOB) were present in 72% of patients at the time of presentation. SOB was the more common presenting symptom (81%) compared to cough (19%). In 95% of cases, another visceral organ was involved (most commonly liver or kidneys). 45% of cases were initially misdiagnosed as pneumonia and were treated with empiric antimicrobials. In a multivariate regression, a latency of 30?days or less and an age of 60 or less were associated with development of ARDS. Gender and eosinophil count were not associated with severity of pulmonary manifestations. All patients recovered, and in the vast majority of cases (95%), parenteral steroids were used for treatment in addition to supportive care and symptomatic management. Conclusion:Albeit rare, DRESS is a potentially life-threatening syndrome which may present with a myriad of pulmonary signs and symptoms. Pulmonary manifestations are less common but are typically seen in more severe cases. Pulmonary manifestations may be a presenting sign of DRESS, and timely recognition is important in order to stop offending medication and decrease morbidity and mortality.
