12-year followup study of epidemic Spanish toxic oil syndrome

To determine the longterm clinical and functional outcome among a large group of patients with toxic oil syndrome (TOS).

One hundred individuals with onset in 1981 were randomly selected for followup in 1993 from a national TOS database. Clinical and laboratory data for 1981 were collected by retrospective chart review. Ninety-one survivors were reevaluated in 1993 by direct interview, examination, the Health Assessment Questionnaire (HAQ), and the visual analog scale (VAS) for pain. A semiquantitative Total Clinical Score (TCS) was created to assess relative global outcome in 1993, for comparison with the HAQ, and for developing a predictive model based on disease manifestations at onset.

Fifty-eight percent continue to have symptoms consisting predominantly of muscle cramping (60%), fatigue (55%), arthralgias (43%), subjective cognitive impairment (44%), psychiatric disease (27%), and soft tissue tenderness (22.5%). Severe neuromuscular sequelae, sclerodermatous skin disease, or pulmonary hypertension were not detected. The most notable laboratory findings at followup were hypercholesterolemia (55%) and hyperglycemia (14.5%). A good correlation was demonstrated between both the HAQ and the VAS for pain with the TCS. A statistical model indicated that alopecia, Raynaud's phenomenon, and sensory neuropathy were predictive of outcome.

TOS is commonly associated with longterm neuromuscular and articular disease. Multiple factors implicated in the adaptation to chronic disease may contribute to this morbidity.