Thelackoftearsleadstodryingofthecornealepithelium,whichbecomesinflamed,eroded,andulcerated;theoralmucosamayatrophy,withinflammatoryfissuringandulceration;anddrynessandcrustingofthenosemayleadtoulcerationsandevenperforationofthenasalseptum.
Sjögren syndrome occurs most commonly in women between 50 and 60 years of age. As might be expected, symptoms result from inflammatory destruction of the exocrine glands. Keratoconjunctivitis produces blurred vision, burning, and itching, and thick secretions that accumulate in the conjunctival sac. Xerostomia results in difficulty in swallowing solid foods, a decrease in taste, cracks and fissures in the mouth, and dryness of the buccal mucosa. Parotid gland enlargement is present in half the patients; dryness of the nasal mucosa, epistaxis, recurrent bronchitis, and pneumonitis are other symptoms. Manifestations of extraglandular disease are seen in one third of patients and include synovitis, pulmonary fibrosis, and peripheral neuropathy. In contrast to SLE, glomerular lesions are rare in Sjögren syndrome. Defects of tubular function, however, including renal tubular acidosis, uricosuria, and phosphaturia, often are seen and are associated with tubulointerstitial nephritis (Chapter 14). About 60% of patients have another accompanying autoimmune disorder, such as rheumatoid arthritis.
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Fig. 5.27 Sjögrensyndrome.(A)Enlargementofthesalivarygland.(B)Intenselymphocyticandplasmacellinfiltrationwithductalepithelialhyperplasiainasalivarygland.(A,Courtesy of Dr. Richard Sontheimer, Department of Dermatology, University of Texas Southwestern Medical School, Dallas,Texas. B,Courtesy of Dr. Dennis Burns,Department of Pathology,University of Texas Southwestern Medical School,Dallas,Texas.)
Sjögrensyndromeisaninflammatorydiseasethatprimarilyaffectsthesalivaryandlacrimalglands,causingdrynessofthemouthandeyes.
ThediseaseisbelievedtobecausedbyanautoimmuneT-cellreactionagainstanunknownselfantigenexpressedintheseglands,orimmunereactionsagainsttheantigensofavirusthatinfectsthetissues.
Systemic sclerosis is an immunologic disorder characterized by excessive fibrosis in multiple tissues, obliterative vascular disease, and evidence of autoimmunity, mainly the production of multiple autoantibodies. Although the term scleroderma is ingrained in clinical medicine, the name systemic sclerosis is preferred because excessive fibrosis is seen in multiple organs. Cutaneous involvement is the usual presenting manifestation and eventually appears in approximately 95% of cases, but it is the visceral involvement—of the gastrointestinal tract, lungs, kidneys, heart, and skeletal muscles—that is responsible for most of the morbidity and mortality. Disease limited to the skin is also called localized scleroderma.
Systemic sclerosis is classified into two groups on the basis of its course:
Diffuse systemic sclerosis, characterized by initial widespread skin involvement, with rapid progression and early visceral involvement
Limited systemic sclerosis, with relatively mild skin involvement, often confined to the fingers and face. Involvement of the viscera occurs late, so the disease generally follows a fairly benign course. This presentation also is called CREST syndrome because of its frequent features of calcinosis, Raynaud phenomenon, esophageal dysmotility, sclerodactyly, and telangiectasia.
The cause of systemic sclerosis is not known, but the disease likely results from three interrelated processes— autoimmune responses, vascular damage, and collagen deposition (