Wednesday, May 5, 2021
Monday, May 3, 2021
Tuesday, April 20, 2021
|ULTRASTRUCTURE OF PULMONARY ALVEOLI AND CAPILLARIES|
Sunday, March 7, 2021
DERMATOMYOSITIS AND POLYMYOSITIS
Polymyositis and dermatomyositis are two of the idiopathic inﬂammatory myopathies, a group of rare systemic autoinﬂammatory disorders of unknown cause. They are characterized by proximal muscle weakness (most patients present with the subacute onset of weakness and myalgias), increased serum skeletal muscle enzymes, characteristic electromyography abnormalities, and the presence of inﬂammatory cell inﬁltrates in muscle tissue. Patients with dermatomyositis are deﬁned by the additional presence of an exanthem, most commonly a purple discoloration of the eyelids (heliotrope rash) or a symmetric, palpable, erythematous rash over the extensor surfaces of the metacarpophalangeal and proximal interphalangeal joints of the ﬁngers (Gottron papules). Extramuscular organ involvement is common, particularly the skin, joints, and lungs. Pulmonary complications are a major cause of morbidity and mortality. These can be either primarily associated with the underlying autoinﬂammatory disorder or secondary to the muscle weakness. As with all autoimmune disorders, drug-induced disease and infection should always be an early consideration. Myositis speciﬁc ﬁndings include hypoventilation, aspiration pneumonia, and interstitial lung disease (ILD).
SYSTEMIC LUPUS ERYTHEMATOSUS
Systemic lupus erythematosus (SLE) is a systemic autoinﬂammatory disorder that most commonly affects women of childbearing age. Hispanics and African Americans present earlier and with more active and aggressive disease than whites. When SLE is diagnosed after age 50 years, there is a lower female : male ratio; a higher incidence of neurologic, serosal, and pulmonary involvement; greater accumulated organ damage; and higher mortality.
SYSTEMIC SCLEROSIS (SCLERODERMA)
Systemic sclerosis (SSc) is a systemic autoimmune disorder that clinically involves the skin, gastrointestinal tract, musculoskeletal system, kidneys, heart, and lungs. Most patients are women in their fourth and ﬁfth decades of life. Common presenting complaints include Raynaud phenomenon; tightening of the skin of the face, upper extremities, and thorax; dysphagia; cough; and dyspnea. A variety of clinical SSc subtypes exist; diffuse cutaneous, limited, and sine scleroderma are all deﬁned by speciﬁc patterns of skin involvement. Some pulmonary abnormality can be identiﬁed in almost all patients, and certain phenotypes are more commonly associated with speciﬁc pulmonary complications than others. However, all known pulmonary manifestations have been described in each of the SSc subtypes, and one should not exclude a particular pulmonary disorder based solely on a clinical or serologic scleroderma phenotype.
Rheumatoid arthritis (RA) is a systemic, autoinﬂammatory disorder deﬁned by its characteristic attack on the diarthroidal joints. It affects approximately 1% of the adult U.S. population, with a two-to-one female pre-dominance. When compared with the general population, overall mortality is increased, with the median survival decreased by 1 decade. A signiﬁcant portion of the clinical impact of the disease is attributable to its extraarticular manifestations (ExRAs). ExRAs are common, the prevalence of clinically “severe” ExRA ranging up to 40%, and are dominated by cardiac, vascular, and pulmonary disorders.