CHAPTER 310

Poisoning

Poisoning is the harmful effect that occurs when a toxic substance is swallowed, is inhaled, or comes in contact with the skin, eyes, or mucous membranes, such as those of the mouth or nose.

Possible poisonous substances include prescription and over-the-counter drugs, illicit drugs, gases, chemicals, vitamins, and food.

Some poisons cause no damage, whereas others can cause severe damage or death.

The diagnosis is based on symptoms, on information gleaned from the poisoned person and bystanders, and sometimes on blood and urine tests.

Medications should always be kept in original childproof containers and kept out of the reach of children.

Treatment consists of supporting the person, preventing additional absorption of the poison, and sometimes increasing elimination of the poison.

Poisoning is the most common cause of nonfatal accidents in the home. More than 2 million people suffer some type of poisoning each year in the United States. Drugs—prescription, over the counter, and illicit—are the most common source of serious poisonings and poisoning-related deaths. Other common poisons include gases, household products, agricultural products, plants, industrial chemicals, vitamins, and foods (particularly certain species of mushrooms— see page 153—and fish—see page 155). However, almost any substance ingested in sufficiently large quantities can be toxic.

Young children are particularly vulnerable to accidental poisoning in the home, as are older people, often from confusion about their drugs. Also vulnerable to accidental poisoning are hospitalized people (from drug errors) and industrial workers (from exposure to toxic chemicals). Poisoning may also be a deliberate attempt to commit murder or suicide. Most adults who attempt suicide by poisoning take more than one drug and also consume alcohol.

The damage caused by poisoning depends on the poison, the amount taken, and the age and underlying health of the person who takes it. Some poisons are not very potent and cause problems only with prolonged exposure or repeated ingestion of large amounts. Other poisons are so potent that just a drop on the skin can cause severe damage.

Some poisons cause symptoms within seconds, whereas others cause symptoms only after hours or even days. Some poisons cause few obvious symptoms until they have damaged vital organs—such as the kidneys or liver—sometimes permanently.

Nontoxic Household Products*

Adhesives

Antacids

Bath oil†

Bathtub toys (floating)

Bleach (less than 5% sodium hypochlorite)

Body conditioners

Bubble bath soaps (detergents)†

Candles

Carboxymethylcellulose (dehydrating material packed

with film, books, and other products)

Chalk (calcium carbonate)

Colognes

Cosmetics

Crayons

Deodorants

Deodorizers, spray and refrigerant

Fabric softeners

Hand lotions and creams

Hydrogen peroxide (3% medicinal)

Incense

Indelible markers

Ink (black, blue)

“Lead” pencils (which are really made of graphite)

Magic markers

Matches

Mineral oil†

Modeling clay

Newspaper

Perfumes

Petroleum jelly

Putty

Sachets (essential oils, powders)

Shaving creams and lotions

Soap and soap products

Suntan preparations

Sweetening agents (saccharin, aspartame)

Toothpaste with or without fluoride

Vitamins (children’s multiple with or without iron)

Water colors

Wax or paraffin

Zinc oxide

Zirconium oxide

* Almost any substance can be toxic if ingested in sufficient amounts.

†Moderately viscous (thick) substances like oils and detergents are not toxic if ingested but can cause significant lung injury if they are inhaled or aspirated into the lungs.

First Aid

The first priority in helping a poisoned person is for bystanders not to become poisoned themselves. People exposed to a toxic gas should be removed from the source quickly, preferably out into fresh air, but rescue attempts should be done by professionals. Special training and precautions must be considered to avoid being overcome by the toxic gases or chemicals during rescue attempts.

In chemical spills, all contaminated clothing, including socks and shoes, and jewelry should be removed immediately. The skin should be thoroughly washed with soap and water. If the eyes have been exposed, they should be thoroughly flushed with water or saline. Rescuers must be careful to avoid contaminating themselves.

If the person appears very sick, emergency medical assistance (911 in most areas of the United States) should be called. Bystanders should do cardiopulmonary resuscitation (CPR) if needed (see page 1942). If the person does not appear very sick, bystanders can contact the nearest poison center for advice. In the United States, the local poison center can be reached at 800-222-1222. More information is available at the American Association of Poison Control Centers web site (www.aapcc.org). If the caller knows the identity of the poison and the amount ingested, treatment can often be initiated at home if this is recommended by the poison center.

Containers of the poisons and all drugs that might have been taken by the poisoned person (including over-the-counter products) should be saved and given to the doctor or rescue personnel. The poison center may recommend giving the poisoned person activated charcoal (see page 2008) before arrival at a hospital and, rarely, may recommend giving syrup of ipecac to induce vomiting, particularly if the person must travel far to reach the hospital. However, unless specifically instructed to, charcoal and syrup of ipecac should not be given in the home or by first responders (such as ambulance personnel). Syrup of ipecac has unpredictable effects, often causes prolonged vomiting, and may not remove substantial amounts of poison from the stomach.

Diagnosis

Identifying the poison is helpful to treatment. Labels on bottles and other information from the person, family members, or coworkers best enable the doctor or the poison center to identify poisons. Laboratory testing is much less likely to identify the poison, and many drugs and poisons cannot be readily identified or measured by the hospital. Sometimes, urine and blood tests may help in identification as well. Blood tests can sometimes reveal the severity of poisoning, but only with only a small number of poisons.

For certain poisonings, abdominal x-rays may show the presence and location of the ingested substances. Poisons that may be visible on x-rays include iron, lead, arsenic, other metals, and large packets of cocaine or other illicit drugs swallowed by so-called body packers or drug mules.

Prevention

In the United States, widespread use of child-resistant containers with safety caps has greatly reduced the number of poisoning deaths in children younger than age 5. To prevent accidental poisoning, drugs should be kept in their original containers. Toxic substances, such as insecticides and cleaning agents, should not be put in drink bottles or cups, even briefly. Other preventive measures include clearly labeling household products, storing drugs and toxic substances in cabinets that are locked and out of the reach of children, and using carbon monoxide detectors. Expired drugs should be disposed by mixing them with cat litter or some other nontempting substance and putting them in a trash container that is inaccessible to children. All labels should be read before taking or giving any drugs or using household products.

Limiting the amount of over-the-counter pain relievers in a single container reduces the severity of poisonings, particularly with acetaminophen, aspirin, or ibuprofen. The identifying marks printed on pills and capsules by the drug manufacturer can help prevent confusion and errors by people, pharmacists, and health care practitioners.

Did You Know…

In the United States, the local poison center can be reached by dialing 1-800-222-1222.

Treatment

Some people who have been poisoned must be hospitalized. With prompt medical care, most recover fully.

The principles for the treatment of all poisoning are the same:

Support breathing and blood pressure

Prevent additional absorption

Increase elimination of the poison

Give specific antidotes (substances that eliminate, inactivate, or counteract the effects of the poison), if available

Prevent reexposure

The usual goal of hospital treatment is to keep people alive until the poison disappears or is inactivated by the body. Eventually, most poisons are inactivated by the liver or are passed into the urine. There are no specific antidotes for many serious poisonings.

Stomach emptying (stomach pumping), once commonly done, is now usually avoided because it removes only a small amount of the poison and can cause serious complications. Stomach emptying rarely improves a person’s outcome. However, stomach emptying may be done if an unusually dangerous poison is involved or if the person appears very sick. In this procedure, a tube is inserted through the mouth or nose into the stomach. Water is poured into the stomach through the tube and is then drained out (gastric lavage). This procedure is repeated several times. If people are drowsy because of the poison, doctors usually first put a plastic breathing tube through the mouth into the windpipe (endotracheal intubation). Endotracheal intubation helps keep the gastric lavage liquid from running into the lungs. In the hospital, doctors do not give syrup of ipecac to empty the stomach because its effects are inconsistent.

For many swallowed poisons, hospital emergency departments may give activated charcoal. Activated charcoal binds to the poison that is still in the digestive tract, preventing its absorption into the blood. Charcoal is usually taken by mouth but may have to be given through a tube that is inserted through the nose into the stomach. Sometimes doctors give charcoal every 4 to 6 hours to help cleanse the body of the poison. Not all poisons are inactivated by charcoal. For example, charcoal does not bind alcohol, iron, or many household chemicals.

If a poisoning remains life threatening despite the use of charcoal and antidotes, more complicated treatments may be needed. The most common involve filtering poisons directly from the bloodstream— hemodialysis (which uses an artificial kidney [dialyzer] to filter the poisons—see page 266) or charcoal hemoperfusion (which uses charcoal to help eliminate the poisons). For either of these methods, small tubes (catheters) are inserted into blood vessels, one to drain blood from an artery and another to return blood to a vein. The blood is passed through special filters that remove the toxic substance before being returned to the body. Sometimes a solution containing sodium bicarbonate (the chemical in baking soda) is given by vein to make the urine more alkaline or basic (as opposed to acidic). This can increase the amount of certain drugs (such as aspirin and barbiturates) excreted in the urine.

Poisoning often requires additional treatment, termed supportive care, designed to stabilize the heart, blood pressure, and breathing until the poison disappears or is inactivated. For example, a person who becomes very drowsy or comatose may need a breathing tube inserted into the windpipe. The tube is then attached to a ventilator, which mechanically supports the person’s breathing. The tube prevents vomit from entering the lungs, and the ventilator ensures adequate breathing. Treatment also may be needed to control seizures, fever, or vomiting.

If the kidneys stop working, hemodialysis is necessary. If liver damage is extensive, treatment for liver failure may be necessary. If the liver or kidneys sustain permanent, severe damage, organ transplantation may be needed.

People who attempt suicide by poisoning need mental health evaluation and appropriate treatment.

Acetaminophen Poisoning

People sometimes ingest too many products that contain acetaminophen and accidentally poison themselves.

Depending on the amount of acetaminophen in the blood, symptoms range from none at all to vomiting and abdominal pain to liver failure and death.

The diagnosis is based on the amount of acetaminophen in the blood and results of liver function tests.

Acetylcysteine is given to reduce the toxicity of the acetaminophen.

More than 100 products contain acetaminophen, a common over-the-counter pain reliever that is also present in many combination prescription drugs. If several similar products are consumed at a time, a person may inadvertently take too much acetaminophen. Many preparations intended for use in children are available in liquid, tablet, and capsule form, and a parent may try several preparations simultaneously or within several hours to treat a fever or pain, not realizing they all contain acetaminophen.

Acetaminophen usually is a very safe drug even in large doses, but it is not harmless. To cause poisoning, several times the recommended dose of acetaminophen must be taken. For example, a person who weighs 150 pounds generally needs to take about 30 325-milligram tablets before toxic effects due to a single overdose are possible. Death is extremely unlikely unless the person takes more than 40 325-milligram tablets. Toxicity also may develop if multiple smaller doses are taken over time. In toxic doses, acetaminophen can damage the liver. Liver failure can follow.

Symptoms and Diagnosis

Most overdoses cause no immediate symptoms. The level of acetaminophen in the blood, measured 2 to 4 hours after ingestion, may help predict the severity of the liver damage. If the overdose is very large, symptoms develop in four stages. In stage 1 (after several hours), the person may vomit but does not seem ill. Many people have no symptoms until stage 2 (after 24 to 72 hours), when nausea, vomiting, and abdominal pain may develop. At this stage, blood tests show that the liver is functioning abnormally. In stage 3 (after 3 to 4 days), vomiting becomes worse. Tests show that the liver is functioning poorly, and jaundice (yellowing of the eyes and skin) and bleeding develop. Sometimes the kidneys fail and the pancreas becomes inflamed (pancreatitis). In stage 4 (after 5 days), the person either recovers or experiences failure of the liver and often other organs, which may be fatal.

Treatment

If acetaminophen was taken within the previous several hours, activated charcoal may be given.

If the level of acetaminophen in the blood is high, acetylcysteine is generally given by mouth or by vein to reduce the toxicity of the acetaminophen. Acetyl-cysteine is given repeatedly, for one to several days. This antidote helps prevent liver injury but does not reverse injury that has already occurred. Therefore, acetylcysteine must be given before liver injury occurs. Treatment for liver failure or liver transplant may also be necessary.

Aspirin Poisoning

Aspirin poisoning can occur acutely after taking a high dose or develop gradually after taking low doses repeatedly.

Symptoms may include ringing in the ears, nausea, vomiting, drowsiness, confusion, and rapid breathing.

The diagnosis is based on blood tests.

Treatment involves giving activated charcoal by mouth or stomach tube, giving fluids and bicarbonate by vein, and, for severe poisoning, undergoing hemodialysis.

Ingestion of aspirin and similar drugs (salicylates) can lead to rapid poisoning due to an overdose. The dose necessary to cause acute poisoning, however, is quite large. A person weighing about 150 pounds would have to consume more than 30 325-miligram tablets to develop even mild poisoning. An acute aspirin overdose, therefore, is seldom accidental.

Gradual aspirin poisoning can develop unintentionally by taking aspirin repeatedly at much lower doses. Children with fever who are given only slightly higher than the prescribed dose of aspirin for several days may develop poisoning, although children are rarely given aspirin to treat fever because of the risk of development of Reye’s syndrome (see box on page 1769). None of the over-the-counter cough and cold preparations sold in the United States for children contains aspirin; most contain either acetaminophen or ibuprofen. Adults, many of them elderly, can develop poisoning gradually after several weeks of use. The dosage of aspirin recommended to people with coronary artery disease to reduce the risk of heart attack (1 baby aspirin, 1/2 of an adult aspirin, or 1 full adult aspirin daily) is too small to cause gradual poisoning.

The most toxic form of salicylate is oil of winter-green (methyl salicylate). Methyl salicylate is a component of products such as liniments and solutions used in hot vaporizers. A young child can die from swallowing less than 1 teaspoonful of pure methyl salicylate. Far less toxic are over-the-counter products containing bismuth subsalicylate (used to treat infections of the digestive tract), which can cause poisoning after several doses.

Did You Know…

A young child can die from swallowing less than 1 teaspoonful of oil of wintergreen, which is found in solutions used in hot vaporizers.

Symptoms

The first symptoms of acute aspirin poisoning are usually nausea and vomiting followed by rapid breathing, ringing in the ears, and sweating. Later, if poisoning is severe, the person can develop lightheadedness, fever, drowsiness, hyperactivity, confusion, seizures, destroyed muscle tissue (rhabdomyolysis), kidney failure, and difficulty breathing.

The symptoms of gradual aspirin poisoning develop over days or weeks. Drowsiness, subtle confusion, and hallucinations are the most common symptoms. Lightheadedness, rapid breathing, shortness of breath, fever, dehydration, low blood pressure, a low oxygen level in the blood (hypoxia), a buildup of lactic acid in the blood (lactic acidosis), fluid in the lungs (pulmonary edema), seizures, and brain swelling can develop.

Diagnosis and Treatment

A blood sample is taken to measure the precise level of aspirin in the blood. Measurement of the blood pH (amount of acid in the blood) and the level of carbon dioxide or bicarbonate in the blood also can help doctors determine the severity of poisoning. Tests are usually repeated several times during treatment to reveal whether the person is recovering.

Activated charcoal is given as soon as possible and reduces aspirin absorption. For moderate or severe poisoning, fluids containing sodium bicarbonate are given by vein. Unless there is kidney damage, potassium is added to the fluid. This mixture moves aspirin from the bloodstream into the urine. If the person’s condition is worsening despite other treatments, hemodialysis (which uses an artificial kidney [dialyzer] to filter the poisons—see page 266) can remove aspirin, other salicylates, and acids from the blood. Other symptoms such as fever or seizures are treated as necessary.

Carbon Monoxide Poisoning

Carbon monoxide poisoning is common.

Symptoms may include headache, nausea, drowsiness, and confusion.

The diagnosis is based on blood tests.

Carbon monoxide detectors and adequate venting of furnaces and other sources of indoor combustion help prevent carbon monoxide poisoning.

Treatment includes fresh air and high concentrations of oxygen.

Carbon monoxide is a colorless, odorless gas that, when inhaled, prevents the blood from carrying oxygen and prevents the tissues from using oxygen effectively. Small amounts are not usually harmful, but poisoning occurs if levels of carbon monoxide in the blood become too high. Carbon monoxide disappears from the blood after several hours.

Smoke from fires commonly contains carbon monoxide, particularly when combustion of fuels is incomplete. If improperly vented, automobiles, furnaces, hot water heaters, gas heaters, kerosene heaters, and stoves (including wood stoves and stoves with charcoal briquettes) can cause carbon monoxide poisoning. Inhaling tobacco smoke produces carbon monoxide in the blood, but usually not enough to result in symptoms of poisoning.

Did You Know…

Carbon monoxide is one of the most common causes of poisoning deaths.

Symptoms and Diagnosis

Mild carbon monoxide poisoning causes headache, nausea, dizziness, difficulty concentrating, vomiting, drowsiness, and poor coordination. Most people who develop mild carbon monoxide poisoning recover quickly when moved into fresh air. Moderate or severe carbon monoxide poisoning causes impaired judgment, confusion, unconsciousness, seizures, chest pain, shortness of breath, low blood pressure, and coma. Thus, most victims are not able to move themselves and must be rescued. Severe poisoning is often fatal. Rarely, weeks after apparent recovery from severe carbon monoxide poisoning, symptoms such as memory loss, poor coordination, and problems with vision (which are referred to as delayed neuropsychiatric symptoms) develop.

Carbon monoxide is dangerous because a person may not recognize drowsiness as a symptom of poisoning. Consequently, someone with mild poisoning can go to sleep and continue to breathe the carbon monoxide until severe poisoning or death occurs. Some people with long-standing, mild carbon monoxide poisoning caused by furnaces or heaters may mistake their symptoms for other conditions, such as the flu or other viral infections.

Carbon monoxide poisoning is diagnosed by measuring the level of carbon monoxide in the blood.

Prevention and Treatment

To prevent poisoning, indoor sources of combustion, such as gas space heaters and wood stoves, require proper installation and ventilation. If such ventilation is impractical, an open window can limit carbon monoxide accumulation by allowing it to escape from the building. Exhaust pipes attached to furnaces and other heating appliances need periodic inspections for cracks and leaks. Chemical detectors are available for the home that can sense carbon monoxide in the air and sound alarms when it is present. If carbon monoxide is suspected in a home, windows should be opened, and the home should be evacuated and evaluated for the source of the carbon monoxide. Constant monitoring with such detectors can identify carbon monoxide before poisoning develops. Like smoke detectors, carbon monoxide detectors are recommended for all homes.

For mild poisoning, fresh air may be all that is needed. To treat more severe poisoning, high concentrations of oxygen are given, usually through a face mask. Oxygen hastens the disappearance of carbon monoxide from the blood and relieves symptoms. The value of high-pressure oxygen treatment (in a hyperbaric chamber) remains uncertain.

Caustic Substances Poisoning

When swallowed, caustic substances can burn all tissues they touch—from the lips to the stomach.

Symptoms may include pain (particularly with swallowing), coughing, shortness of breath, and vomiting.

A doctor inserts a flexible viewing tube (endoscope) down the esophagus to look for burns and determine the severity of the injury.

Treatment is determined by the extent of the damage and may involve surgery.

Caustic substances (strong acids and alkalis), when swallowed, can burn the tongue, mouth, esophagus, and stomach. These burns may cause perforation (piercing) of the esophagus or stomach. Food and saliva leaking from a perforation cause severe, sometimes deadly infection within the chest (mediastinitis or empyema) or abdomen (peritonitis). Burns that do not perforate can result in scarring of the esophagus and stomach.

Industrial products are usually the most damaging because they are highly concentrated. However, some common household products, including drain and toilet bowl cleaners and some dishwasher detergents, contain damaging caustic substances, such as sodium hydroxide and sulfuric acid.

Caustic substances are available as solids and liquids. The burning sensation of a solid particle sticking to a moist surface (such as the lips) may prevent a person from consuming much of the product. Because liquids do not stick, it is easier to consume more of the product, and the entire esophagus can be damaged. Liquids also may be inhaled (aspirated) into the airways, leading to upper airway injury.

Symptoms

Pain in the mouth and throat develops rapidly, usually within minutes, and can be severe, particularly with swallowing. Coughing, drooling, an inability to swallow, vomiting, vomiting blood, and shortness of breath may occur. In severe cases involving strong caustic substances, a person may develop very low blood pressure (shock), difficulty breathing, or chest pain, possibly leading to death. Airway burns may cause coughing, rapid breathing, or shortness of breath.

Perforation of the esophagus or stomach may occur within hours, during the first week after ingestion, or any time in between, often after vomiting or severe coughing. The esophagus may perforate into the area between the lungs (the mediastinum) or into the area surrounding the lungs (the pleural cavity). Either circumstance causes severe chest pain, fever, rapid heart rate, rapid breathing, very low blood pressure, and the need for surgery. Peritonitis results in severe abdominal pain.

Scarring of the esophagus results in narrowing (stricture), which causes difficulty in swallowing. Strictures usually develop weeks after the burn, sometimes in burns that initially caused only mild symptoms. People with scars and damage to the esophagus often develop cancer of the esophagus years after the injury.

Diagnosis and Treatment

The mouth is examined for chemical burns. Because the esophagus and stomach may be burned without the mouth being burned, the doctor may insert an endoscope down the esophagus to look for burns, particularly if the person drools or has difficulty swallowing. Directly inspecting the area allows the doctor to determine the severity of the injury and possibly to predict the risk of subsequent narrowing and the possible need for surgical repair of the esophagus.

The extent of damage determines treatment. People with severe burns sometimes need immediate surgery to remove severely damaged tissue. Corticosteroids and antibiotics may be used to try to prevent strictures and infections, but whether these drugs are helpful is not clear.

Because caustic substances can cause as much damage returning up the esophagus as they did when swallowed, a person who has swallowed a caustic substance should not be made to vomit. Syrup of ipecac and charcoal are not given.

If burns are mild, the person may be encouraged to begin drinking milk or water fairly soon in order to dilute the corrosive liquid in the stomach. Drinking can begin at home or on the way to the hospital. If the person cannot drink, fluids are given by vein until drinking is possible. Perforations are treated with antibiotics and surgery. If strictures develop, a bypass tube (stent) may be placed in the narrowed portion of the esophagus to prevent esophageal closure and to allow for future widening (dilation). Repeated widening may be needed for months or years. For severe strictures, surgery to rebuild the esophagus may also be necessary.

Hydrocarbon Poisoning

Sniffing glue or swallowing gasoline, paint thinners, some cleaning products, or kerosene can cause hydrocarbon poisoning.

Swallowing or inhaling hydrocarbons can cause lung irritation, with coughing, choking, shortness of breath, and neurologic problems.

Sniffing or breathing fumes can cause irregular heartbeats, rapid heart rate, or sudden death, particularly after exertion or stress.

The diagnosis is based on a description of the events, the characteristic odor of petroleum on the person’s breath or clothing, and sometimes a chest x-ray.

Treatment involves removing contaminated clothing, washing the skin, and giving oxygen and antibiotics to people with breathing problems or pneumonia.

Petroleum products, cleaning products, and glues contain hydrocarbons (substances composed largely of hydrogen and carbon). Many children younger than age 5 are poisoned by swallowing petroleum products, such as gasoline, kerosene, and paint thinners, but most recover. At greater risk are adolescents who intentionally breathe the fumes of these products to become intoxicated, a type of drug abuse called huffing, bagging, sniffing, glue sniffing, or solvent inhalant abuse (see page 2099).

Swallowed hydrocarbons can enter and irritate the lungs, a serious condition in itself (chemical pneumonitis), and can lead to severe pneumonia. Lung involvement is a particular problem with thin, easy-flowing hydrocarbons such as mineral seal oil, which is used in furniture polish. Severe poisoning also can affect the brain, heart, bone marrow, and kidneys. Thick, less-runny hydrocarbons such as lamp oil and mineral oil are less likely to enter the lungs but can cause severe and persistent irritation if they do.

Did You Know…

A person who gets high by breathing hydrocarbon fumes may die suddenly.

Symptoms

A person usually coughs and chokes after swallowing hydrocarbons. A burning sensation can develop in the stomach, and the person may vomit. If the lungs are affected, the person continues to cough intensely. Breathing becomes rapid, and the skin may become bluish (cyanosis) because of low levels of oxygen in the blood. Young children may have cyanosis, hold their breath, and cough persistently.

Hydrocarbon ingestion also causes neurologic symptoms, including drowsiness, poor coordination, stupor or coma, and seizures. Inhalation of certain hydrocarbons may induce fatal irregular heartbeats or cardiac arrest, especially after exertion or stress.

Diagnosis and Treatment

Hydrocarbon poisoning is diagnosed based on a description of the events and the characteristic odor of petroleum on the person’s breath or clothing or if a container is found near the person. Paint residue on the hands or around the mouth may suggest recent paint sniffing. Pneumonia and chemical pneumonitis are diagnosed with a chest x-ray and by measuring the level of oxygen in the blood (see page 455).

To treat poisoning, contaminated clothing should be removed, and the skin should be washed. If the person has stopped coughing and choking, particularly if the ingestion was small and accidental, treatment at home is possible. Home treatment should be discussed with someone at a poison center. People with breathing problems are hospitalized. If pneumonia or chemical pneumonitis develops, hospital treatment can include oxygen and, if severe, a ventilator. Antibiotics help if pneumonia develops. Recovery from pneumonia typically takes about a week but may take much longer if thick, syrup-like hydrocarbons such as lamp oil or mineral oil have entered the lungs.

Insecticide Poisoning

Many insecticides can cause poisoning after being swallowed, inhaled, or absorbed through the skin.

Symptoms may include eye tearing, coughing, and breathing difficulties.

The diagnosis is based on symptoms, blood tests, and a description of events surrounding the poisoning.

Several drugs are effective in treating serious poisonings.

The properties that make insecticides deadly to insects can sometimes make them poisonous to humans. Most serious insecticide poisonings result from the organophosphate and carbamate types of insecticides, particularly when used in suicide attempts. Examples of organophosphates include malathion, parathion, diazinon, dichlorvos, chlorpyrifos, and sarin. Some of these compounds are derived from nerve gases. Pyrethrins and pyrethroids, which are other commonly used insecticides, are derived from flowers and usually are not poisonous to humans.

Many insecticides can cause poisoning after being swallowed, inhaled, or absorbed through the skin. Some insecticides are odorless, thus the person is unaware of being exposed to them. Organophosphate and carbamate insecticides make certain nerves “fire” erratically, causing many organs to become overactive and eventually to stop functioning. Pyrethrins can occasionally cause allergic reactions. Pyrethroids rarely cause any problems.

Symptoms

Organophosphates and carbamates cause eye tearing, blurred vision, salivation, sweating, coughing, vomiting, and frequent bowel movements and urination. Breathing may become difficult, and muscles twitch and become weak. Rarely, shortness of breath or muscle weakness is fatal. Symptoms last hours to days after exposure to carbamates but can last for weeks after exposure to organophosphates.

Pyrethrins can cause sneezing, eye tearing, coughing, and occasional difficulty breathing. Severe symptoms rarely develop.

Diagnosis and Treatment

The diagnosis of insecticide poisoning is based on the symptoms and on a description of the events surrounding the poisoning. Blood tests can confirm organophosphate or carbamate poisoning.

If an insecticide might have contacted the skin, clothing is removed and the skin is washed. Anyone with symptoms of organophosphate poisoning should see a doctor. Atropine, given by vein, can relieve most of the symptoms. Pralidoxime, given by vein, can speed up recovery of nerve function, eliminating the cause of the symptoms. Symptoms of carbamate poisoning also are relieved by atropine but usually not by pralidoxime. Symptoms of pyrethrin poisoning resolve without treatment.

Iron Poisoning

Symptoms develop in stages and begin with vomiting, diarrhea, and abdominal pain.

Liver failure can develop days later.

The diagnosis is based on the person’s history, symptoms, and the amount of iron in the blood.

People with iron poisoning need to be hospitalized.

Pills containing iron are commonly used to treat certain kinds of anemia. Iron also is included in many multiple vitamin supplements. People—especially toddlers—who overdose on these pills may develop iron poisoning. Because many households contain adult multiple vitamin supplements that contain iron, iron overdose is common. However, overdose of iron-containing vitamins, particularly children’s chewable vitamins, usually does not involve enough iron to cause serious poisoning. Overdose of pure iron supplements, however, may cause serious iron poisoning. Prenatal vitamins contain a lot of iron and may poison a small child.

Iron poisoning is the most common cause of fatal poisoning in children younger than age 5. It first irritates the stomach and digestive tract, sometimes causing bleeding. Within hours, iron poisons the cells, interfering with their internal chemical reactions. Within days, the liver can be damaged. Weeks after recovery, the stomach, digestive tract, and liver can develop scars due to the previous irritation.

Symptoms

Serious iron poisoning usually causes symptoms within 6 hours of the overdose. The symptoms of iron poisoning typically occur in 5 stages.

In stage 1 (within 6 hours after the overdose), symptoms include vomiting, vomiting blood, diarrhea, abdominal pain, irritability, drowsiness, unconsciousness, and seizures. If poisoning is very serious, rapid breathing, a rapid heart rate, coma, and low blood pressure may develop.

In stage 2 (6 to 48 hours after the overdose), the person’s condition can appear to improve.

In stage 3 (12 to 48 hours after the overdose), very low blood pressure (shock), fever, bleeding, jaundice, liver failure, and seizures can develop. Sugar levels in the blood can decrease.

In stage 4 (2 to 5 days after the overdose), the liver fails, and people may die from shock, bleeding, and blood-clotting abnormalities. Confusion and sluggishness (lethargy) or coma may develop.

In stage 5 (2 to 5 weeks after the overdose), the stomach or intestines can become blocked by constricting scars. Scarring in either organ can cause crampy abdominal pain and vomiting. Severe scarring of the liver (cirrhosis—see page 222) can develop later.

Diagnosis and Treatment

The diagnosis of iron poisoning is based on the person’s history, symptoms, and the amount of iron in the blood. If many pills have been swallowed, they can sometimes be seen on x-rays of the stomach or intestines.

People with symptoms or high levels of iron in the blood need hospitalization. A large amount of iron can remain in the stomach even after vomiting. A special solution of polyethylene glycol may be given by mouth or through a stomach tube to wash the contents of the stomach and intestines (whole-bowel irrigation), although its effectiveness is unclear. Injections of deferoxamine, which binds iron in the blood, are given.

Lead Poisoning

Some causes of lead poisoning are ingestion of lead paint and eating or drinking from certain imported, improperly lead-glazed ceramics.

Very high levels of lead in the blood may cause personality changes, headaches, loss of sensation, weakness, a metallic taste in the mouth, uncoordinated walking, digestive problems, and anemia.

The diagnosis is based on symptoms and a blood test.

Testing household water, ceramics, and paint for lead can help identify potential sources of lead poisoning.

Treatment consists of stopping exposure to lead and removing accumulated lead from the body.

Although it is far less common since paint containing lead pigment was banned in 1978 and lead was eliminated from most gasoline, lead poisoning (plumbism) is still a major public health problem in cities on the East Coast of the United States.

Workers in industries that handle lead are at risk of lead poisoning, as are children who live in older houses that contain peeling lead paint or lead pipes. During home remodeling, people may be exposed to significant amounts of lead in the form of particles scraped or sanded off during surface preparation for repainting. Young children may eat enough paint chips, particularly during remodeling, to develop symptoms of lead poisoning. Some ceramic glazes contain lead. Ceramic ware, such as pitchers, cups, and plates, made using these glazes (common outside the United States) can leach lead, particularly when in contact with acidic substances (such as fruits, cola drinks, tomatoes, wine, and cider). Lead-contaminated moonshine whiskey and folk remedies are possible sources, as are occasional lead foreign objects in the stomach or tissues (such as bullets or curtain or fishing weights). Bullets lodged in soft tissues may increase levels of lead in the blood, but that process takes years to occur. Certain ethnic cosmetic products and imported herbal products and medicinal herbs contain lead and have caused cluster outbreaks of lead poisoning in immigrant communities.

Lead affects many parts of the body, including the brain, nerves, kidneys, liver, blood, digestive tract, and sex organs. Children are particularly susceptible because lead causes the most damage in nervous systems that are still developing.

If the level of lead in the blood is high for days, symptoms of sudden brain damage (encephalopathy) usually develop. Lower blood levels that are sustained for longer periods of time sometimes cause long-term intellectual deficits.

Did You Know…

Children living in communities where houses are old should be tested for lead poisoning, regardless of whether symptoms are present.

Symptoms and Diagnosis

Many people with mild lead poisoning have no symptoms. Symptoms that do occur usually develop over several weeks or longer. Sometimes symptoms flare up periodically.

Typical symptoms of lead poisoning include personality changes, headaches, loss of sensation, weakness, a metallic taste in the mouth, uncoordinated walking, poor appetite, vomiting, constipation, crampy abdominal pain, bone or joint pains, high blood pressure, and anemia. Kidney damage often develops without symptoms.

Young children may become cranky and their attention span and play activity may decrease over the course of several weeks. Encephalopathy can then begin suddenly and worsen over the next several days, resulting in persistent, forceful vomiting; confusion; sleepiness; and, finally, seizures and coma. Chronic lead poisoning in children may cause intellectual disability (mental retardation), seizure disorders, aggressive behavior disorders, developmental regression, chronic abdominal pain, and anemia.

Adults often develop loss of sex drive, infertility, and, in men, erectile dysfunction (impotence). Encephalopathy rarely develops in adults.

Some symptoms may diminish if exposure to lead is stopped, only to worsen again if exposure is resumed.

The diagnosis of lead poisoning is based on symptoms and a blood test. Adults whose jobs involve handling lead need frequent blood tests. Children living in communities with many older houses, where peeling lead-based paint is common, should also undergo blood tests for lead. In children, bone and abdominal x-rays often show evidence of lead poisoning.

Prevention

Commercially available kits can be used to test household paint, ceramics, and water supplies for lead content. Measures that reduce the risk of household poisoning include regular hand washing, regular washing of children’s toys and pacifiers, and regular cleaning of household surfaces. Dusting affected windowsills weekly with a damp cloth removes some dust that could contain lead from paint. Chipped leaded paint should be repaired. Larger renovation projects to remove leaded paint can release large quantities of lead into the house and should be done professionally. Commercially available faucet filters can remove most lead from drinking water.

Adults exposed to lead dust at work should use appropriate personal protective equipment, change their clothing and shoes before going home, and shower before going to bed.

Treatment

Treatment consists of stopping exposure to lead and removing accumulated lead from the body. If an abdominal x-ray shows lead chips, a special solution of polyethylene glycol is given by mouth or through a stomach tube to wash the contents of the stomach and intestines (a process called whole-bowel irrigation).

Doctors remove lead from the body by giving drugs that bind with the lead (chelation therapy), allowing it to pass into the urine. All drugs that remove lead work slowly and can cause serious side effects.

People with mild lead poisoning are given succimer by mouth. People with more serious lead poisoning are treated in the hospital with injections of chelating drugs, such as dimercaprol, succimer, penicillamine, and edetate calcium disodium. Because chelating drugs also can remove beneficial minerals, such as zinc, copper, and iron, from the body, the person often is given supplements of these minerals.

Even after treatment, many children with encephalopathy develop some degree of permanent brain damage. Kidney damage is also sometimes permanent.