Symptoms, lead poisoning

Anthony S. Fauci et al., eds. Harrison s Principles of Internal Medicine. 14th ed. New York McGraw-Hill, 1998. Source for lead poisoning symptoms. 

Workers who produce or use lead should be aware of possible ha2ards. Symptoms of chronic lead poisoning include fatigue, headache, constipation, uneasy stomach, irritabiHty, poor appetite, metallic taste, weight loss, and loss of sleep. Most of these same symptoms also occur in many common illnesses, such as the flu, thus a physician must rely on tests, such as blood lead analysis, to determine chronic lead poisoning. 

The alimentary symptoms may be overshadowed by neuromuscular dysfunction, accompanied by signs of motor weakness that may progress to paralysis of the exterior muscles or the wrist (wrist drop), and less often, of the ankles (foot drop). Encephalopathy, the most serious result of lead poisoning, frequendy occurs in children as a result of pica, ie, ingestion of inorganic lead compounds in paint chips this rarely occurs in adults. Nephropathy has also been associated with chronic lead poisoning (147). The toxic effects of lead may be most pronounced on the developing fetus. Consequendy, women must be particulady cautious of lead exposure (148). The U.S. Center for Disease Control recommends a blood level of less than 10 p.m per 100 mL for children. 

At neither site is there evidence of absorption of lead to the degree usually associated with clinical symptoms of lead poisoning, and the reported blood-lead levels are not high enough to make this likely. However, a public health concern exists, particularly in the RSR area, since 5 percent of these black children were found to have lead toxicity. 

Referring to the euphoria that is a symptom of tetraethyl lead poisoning, Midgley told the New York World The essential thing necessary to safely handle TEL was careful discipline of our men. . . The minute a man shows signs of exhilaration he is laid off. If he spills the stuff on himself he is fired. Because he doesn t want to lose his job, he doesn t spill it. Apparently, Midgley s generosity and conviviality did not extend to his workers. 

Colic is also a symptom of lead poisoning in children. EPA (1986a) has identified a LOAEL of approximately 60-100 pg/dL for children. This value apparently is based on a National Academy of Sciences (NAS 1972) compilation of unpublished data from the patient groups originally discussed in Chisolm (1962, 1965) and Chisolm and Harrison (1956) in which other signs of acute lead poisoning, such as severe constipation, anorexia, and intermittent vomiting, occurred at 60 pg/dL. 

Full Fanconi syndrome has been reported to be present in some children with lead encephalopathy (Chisolm 1968 Chisolm et al. 1955). According to the National Academy of Sciences (NAS 1972), the Fanconi syndrome is estimated to occur in approximately one out of three children with encephalopathy and PbB levels of approximately 150 pg/dL. Aminoaciduria occurs at PbB levels >80 pg/dL in children with acute symptomatic lead poisoning (Chisolm 1962). The aminoaciduria and symptoms of lead toxicity disappeared after treatment with chelating agents (Chisolm 1962). 

Symptoms of lead poisoning occur after a daily dose of 2 to 4 mg is ingested for a period of a few months, while daily doses of 8 to 10 mg will cause poisoning after only three to four weeks. 

Lead diiodide is toxic if ingested. The symptoms are those of lead poisoning. 

The answer is C. The patient s symptoms represent a composite of neurologic and gastrointestinal dysfunction, which are consistent with the anemia that is due to lead poisoning. Testing for lead would be appropriate for the patient, the other members of the household, and the house itself. Inorganic lead produces the microcytic anemia by inhibition of heme synthesis in erythropoietic cells of the bone marrow. All the other options represent enzymes of heme synthesis or degradation, but none of them are affected by lead. 

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