In the latest Case Record of the Massachusetts General Hospital, a 21-year-old man presented with fever, arthralgias, dyspnea, and periorbital swelling. Examination revealed periorbital edema and erythema. Chest CT revealed bilateral subpleural reticular and ground-glass opacities. Diagnostic tests and a diagnostic procedure were performed.
The presentation of a previously healthy patient with fever, arthritis, rash, and pulmonary lesions should generate a differential diagnosis that includes the categories of infection, cancer, and collagen vascular disease.
• What are the types of interstitial lung disease?
Interstitial lung disease may be idiopathic or associated with an identifiable cause. The subtypes may be distinguished on a clinical or pathological basis. Idiopathic pulmonary fibrosis is the most common type. Others include acute interstitial pneumonitis, cryptogenic organizing pneumonia (previously known as bronchiolitis obliterans with organizing pneumonia), desquamative interstitial pneumonia, lymphocytic interstitial pneumonia, respiratory bronchiolitis interstitial lung disease, and nonspecific interstitial pneumonitis.
• What are characteristics of adult-onset Still’s disease?
The diagnostic criteria for adult-onset Still’s disease include the major features of fever, leukocytosis, rash, arthritis, and arthralgia. A salmon-colored rash is often notable in adult-onset Still’s disease; however, the rash in patients with dark skin tones may appear hyperpigmented rather than salmon colored. Other features may include sore throat, lymphadenopathy, hepatosplenomegaly, and abnormal transaminases. Elevated ferritin levels, although not included in the diagnostic criteria, are usually present in patients with adult-onset Still’s disease. Interstitial lung disease is reported only rarely in conjunction with adult-onset Still’s disease.
Morning Report Questions
Q: What is the antisynthetase syndrome?
A: The antisynthetase syndrome is characterized by the presence of one of the antisynthetase autoantibodies and at least one of the following three clinical features: interstitial lung disease, inflammatory myopathy, or inflammatory polyarthritis. Other supporting features may include fever, Raynaud’s phenomenon, and “mechanic’s hands” (thick, cracked skin, usually on the palm and the radial surface of the digits). To date, eight antisynthetase autoantibodies have been identified, all of which are directed against enzymes that acetylate transfer RNA (tRNA). The one first described and most commonly found is anti-Jo-1 (directed against histidyl-tRNA synthetase). Although they are less common, the seven other autoantibodies in this group (anti-PL-12, anti-PL-7, anti-EJ, anti-OJ, anti-KS, anti-YRS, and anti-Zo) confer a similar clinical phenotype. Most studies have shown that the majority of patients with any antisynthetase autoantibody have interstitial lung disease.
Q: What are the clinical manifestations of dermatomyositis?
A: Dermatomyositis is an inflammatory myopathy, which is characterized by several skin findings. Eyelid edema and erythema with pruritus are very characteristic of the heliotrope rash that is associated with dermatomyositis. Malar erythema also occurs and differs from the typical “butterfly rash” of systemic lupus erythematosus (SLE). In SLE, the nasolabial folds are spared from rash, whereas in dermatomyositis, they are not. Other features include Gottron’s sign, which is an erythematous scaly rash that occurs characteristically on the metacarpalphalangeal (MCP) and interphalangeal joints, and the “shawl sign,” manifested by erythema over the chest and shoulders in a V-shaped distribution. Up to 30 percent of patients with dermatomyositis or polymyositis have the antisynthetase syndrome.