Etiologies of the sicca syndrome: primary systemic amyloidosis and others.

Background: The sicca syndrome has been defined as the occurrence of xerostomia and xerophthalmia. Sjögren's syndrome is the most common cause of the sicca syndrome; however, these two syndromes are not synonymous and there are many potential etiologies of the sicca syndrome. A less known cause of sicca syndrome is amyloidosis that to date has only been reported in the nondermatology literature.

Observations: A 79-year-old man with known amyloidosis presented with persistent xerostomia. He had the classic cutaneous findings of periorbital and "pinch" purpura. A labial biopsy showed diffuse deposition of amorphous eosinophilic material surrounding salivary acini. Apple-green birefringence was noted with Congo red staining and the diagnosis was made of amyloidosis in the minor salivary glands causing xerostomia.

Conclusions: The sicca syndrome can be caused by systemic amyloidosis. Because this fact is not in the dermatologic literature, many dermatologists are not aware of this uncommon presentation. The knowledge of the many causes of the sicca syndrome and an understanding of the differences between this and Sjögren's syndromes are important for any dermatologist.