Hyperviscosity Syndrome in Undifferentiated Connective Tissue Disease: A Diagnostic and Therapeutic Challenge.

Hyperviscosity is an uncommon manifestation of various underlying diseases. Rapid diagnosis and management of the underlying disease is crucial to prevent significant complications, including hypertension, cerebral vascular accidents, pulmonary embolism, bowel ischemia, and ophthalmologic pathologies. Although the acute management of complications arising from hyperviscosity is relatively straightforward, identifying and treating the underlying cause can prove difficult. This case highlights the difficulties of establishing a diagnosis and initiating appropriate management for a patient with hyperviscosity syndrome in a suspected rheumatologic disorder.