Lead poisoning can occur when lead builds up within the body, usually over a long period of time. Young children are vulnerable to lead poisoning and it is important to be aware of this due to lead poisoning being a factor in mental and physical development. Lead poisoning is a medical condition caused by increased levels of lead within the body that interferes with the normal processes of the body and is particularly toxic to children. This occurs because lead and calcium compete for the protein that is important for body functions, especially the nervous system. The lead can displace the calcium from that protein so the calcium will not be able to function properly.
When simplifying the signs and symptoms of lead poisoning, we use the acronym “LEAD”. L represents the lines on the gingiva and long bones; E stands for Encephalopathy and erythrocyte (RBC) basophilic stippling (disease, damage, or malfunction of the brain), A signifies abdominal colic and anemia, and D which stands for drop foot and drop wrist.
Lead inhibits the enzymes that are needed to make Heme—preventing the production of hemoglobin. This causes basophilic stippling of the cells due to lead inhibiting the ribosomal RNA degradation. The red blood cells (RBC) will retain aggregates of ribosomal RNA that causes the stippling of the cells.
Lead poisoning will present itself with a “lead line” in the gingiva (gums) called the Burton’s line. This gray-blue line is visible at the margin of the gum at the base of the teeth. The long bones will also have lead lines in the metaphysis that appear like white bands on an x-ray because the lead is collected within these white bands. The width and density of these lines reflects chronic exposure.
At the RBC level, you will find anemia and basophilic stippling of the red blood cells.
The patient will also have encephalopathy associated with headache and memory loss. Lead poisoning may also cause abdominal colic—pain, cramps, and constipation. Another condition that may occur due to lead poisoning is “foot drop”. The patient may experience permanent damage to the central nervous system and the peripheral nerves.
This condition usually occurs from exposure to lead based paint, typically used in much older homes. Particles from the lead based paint can be inhaled through the air or from contaminated drinking water, as we have seen recently. Extended exposure can cause serious problems, with children being the most vulnerable. They will commonly show signs of: irritability, fatigue, lower IQ, and lack of attentiveness. The child may show signs of encephalopathy, nausea, vomiting, gait disturbances, and seizures. Exposure in adults is usually occupational related. Adults will experience personality changes, headaches, neuropathy, weakness, foot and wrist drop, and stomach aches. Both children and adults will experience pale skin due to anemia because lead interferes with the normal formation of hemoglobin.
When diagnosing lead poisoning, you have to take into consideration the history of exposure, cm lead levels are usually greater than 5—however, some people use higher numbers. If a complete blood count (CBC) test is done, microcytic anemia will be found and in a peripheral blood smear, you will find basophilic stippling (ribosomes). The serum iron will be normal.
When treating lead poisoning, the first step will be to eliminate the source of lead contamination. Next, a chelating agent will be used. During this step, various drugs may be used to help remove lead from the body. A chelating agent will bind the lead into a form that the body can excrete. It is used if lead levels are higher than 45µg/dL in children, and more than 70µg/dL in adults. Dimercaprol (oral chelating agent) is used in cases where patients present with encephalopathy. Succimer is used when there aren’t any signs of encephalopathy.
It is also possible to be contaminated by lead due to a bullet penetrating a joint or if it is introduced into the cerebral spinal fluid. This may cause severe synovitis and low grade lead poisoning. This condition is rare, however it can occur. Lead toxicity can also occur due to contamination of the ground water and soil. Lead poisoning can occur due to ingesting food grown in contaminated soil.