Isoprene, the monomeric unit of natural rubber and naturally occurring terpenes and steroids, is primarily obtained as a by-product of naphtha cracking for ethylene production. It is emitted from plants and trees, has been detected in tobacco smoke and automobile exhaust, and was identified as a
Although easily examined, abnormalities of the tongue can present a diagnostic and therapeutic dilemma for physicians. Recognition and diagnosis require a thorough history, including onset and duration, antecedent symptoms, and tobacco and alcohol use. Examination of tongue morphology and a careful