Pfiesteria and the skin: a practical update for the clinician.

Skin complaints, including an episodic burning sensation on contact with river water, were common among 13 persons with exposure to Maryland's Pocomoke River in the summer of 1997. While the majority of findings on dermatologic examination were unrelated to toxic dinoflagellate exposure, a subset of patients demonstrated otherwise unexplained erythematous, edematous papules on the trunk or extremities. Histopathologic findings were suggestive of an inflammatory, toxic, or allergic process. It may be speculated that these otherwise unexplained cutaneous findings represent a cutaneous reaction to Pfiesteria or Pfiesteria-like toxin; however, further evaluation of future affected persons will be warranted.