Herbicides like dicamba are used to control broad-leaved weeds. This and others of the fenoxicetic family are formulated as ester or salts, sometimes containing up to 50% active ingredient. Muscle weakness and peripheral neuropathy have been reported after occupational exposure. Dicamba is supposed to have low level acute toxicity in man.
We present the observations of two patients admitted to the emergency room of Hospital de Emergencias Clemente Alvarez, Rosario, Argentina, in September 1993. Both patients (18 and 20 year old males) who live in a rural area of Zavalla, Santa Fe, explained they had crossed a wheat field fumigated with MISIL (dicamba dimethylamine salt) fifteen days ago. They got their skin and clothes wet and did not wash themselves then nor in the next few days. They presented similar symptoms: severe muscle spasms, profuse diaphoresis and weakness. Creatine phosphokinase level was markedly raised and others muscle enzymes like lactic dehydrogenase and glutamic and piruvic oxaloacetic transaminasa were all significantly raised indicating rhabdomyolisis. One patient had oliguric acute renal failure and he was treated with hemodialysis. Both made small progress in evolution (30 and 40 days). 24-hour urine sample were taken at the hospital admission and processed by capillary column gas chromatography with electron-capture detection and high-performance liquid chromatography with cuaternary pump and adjustment diode detection. Dicamba identity was confirmed by gas chromatography-mass spectrometry.
We discuss diagnostic difficulties, review of pharmacokinetics of chlorinated phenoxy acid herbicides and association between rhabdomyolisis and dicamba exposition. Limited data about similar cases are available.
Key words: rhabdomyolisis- skin exposure-dicamba