Lead poisoning following ingestion of pieces of lead roofing plates: Pica-like behavior in an adult

Abstract

A 37-year-old man was admitted to hospital after complaining of abdominal pain for the past two weeks. On admission the abdominal radiograph showed multiple radio-opaque flecks dispersed throughout the gastrointestinal tract. Blood testing showed hemoglobin level 8.7 g/dL and a blood lead level of 112.4 μg/dL. The family interview revealed that the patient had pica-like behavior since childhood. He was a site foreman and had been ingesting pieces of roofing plates for a few weeks. The patient was treated with laxatives and CaNa₂EDTA therapy was initiated. The blood lead level then dropped to 69.9 μg/dL. The patient received two subsequent courses of oral succimer and the blood lead level decreased to 59 μg/dL 21 days after the first course. The follow-up abdominal X-ray 20 days after the first examination was normal. Four months later, an outpatient follow-up visit showed a blood lead level within normal limits (14.5 μg/dL) and a psychiatric follow-up was initiated. Lead poisoning following the ingestion of lead-containing foreign bodies is particularly rare in adults, while it is sometimes observed in children. Pica behavior is a well-identified risk factor of lead intoxication in children but is quite exceptional in adults, where it is usually considered to be a psychiatric condition. Other unusual sources of lead poisoning include the ingestion of lead bullets, ceramic lead glaze or glazed earthenware, lead-contaminated candies, ethnic or herbal remedies.

Keywords: :

• Lead poisoning
• Pica
• Adult
• Eating disorder
• CaNa₂EDTA
• Calcium disodium ethylenediaminetetracetate
• Succimer
• DMSA
• Meso-2,3-dimercaptosuccinic acid
• Chelating drugs

Introduction

Most cases of lead poisoning in adults result from chronic occupational exposure, but environmental and domestic intoxications also exist. Unusual sources of lead poisoning following ingestion of lead-contaminated food or drinks have been identified as a cause of lead poisoning in adults. We describe an unusual source of lead exposure and an especially rare modality of lead intoxication by ingestion in an adult.

Case report

A previously healthy 37-year-old man was admitted to Montbrison Hospital, France on the request of his family physician. He had been complaining of increasing abdominal pain over the past two weeks, with a history of constipation. The physical examination on admission was normal. The family interview revealed that the patient had a pica-like behavior; since childhood, he would eat lead, candle wax, plastics, etc. He was a site foreman and had been ingesting pieces of lead roofing plates that he cut with scissors for the past few weeks. On admission, the abdominal X-ray showed multiple radio-opaque metallic flecks dispersed throughout the gastrointestinal (GI) tract lining the ascending and transverse sections of the colon, and in the caecum as well (Fig. 1). There was no evidence of obstruction or perforation. Blood tests revealed anemia (hemoglobin 8.7 g/dL) and leucopenia (white blood cell count 2830/mm³ with 54% neutrophils). No thrombocytopenia was present. The anemia was normochromic normocytic and poorly regenerative (reticulocytes 5.5%); folic acid, vitamin B12 and ferritin levels were normal. A bone marrow examination showed dysplasia, but no basophilic stippling. The initial venous blood lead level (BLL) was 112.4 μg/dL. One week later, Lyon Poison Center was contacted for toxicological advice. Accordingly, GI decontamination with lactulose and administration of laxative gumma was initiated. CaNa₂EDTA therapy (500 mg/m²/day IV for five days) was performed on the following week. No adverse drug effects were observed. Fourteen days after cessation of CaNa₂EDTA therapy, the BLL was 69.9 μg/dL. An oral succimer course (400 mg every eight hours for five days) was started and BLL was 59 μg/dL 21 days later. Therefore, a second course of succimer was performed. At follow-up four months later, the BLL was 14.5 μg/dL. The abdominal X-ray 20 days after the first examination showed no more opacities. Because the patient's history could not help differentiate between sub-acute or chronic lead poisoning, the Poison Center recommendations also included electromyoneurography (EMG) and neuropsychological tests. The neuropsychological test results were strictly normal and the EMG results were within normal limits. The patient was advised not to eat lead any longer and a psychiatrist's advice recommended no drug treatment, but a psychiatric follow-up. Three months later, an acute leukemia was discovered, which explained dysplasia in the bone marrow examination.

Fig. 1.  Abdominal radiograph revealing multiple flecks in the gastrointestinal tract of the patient.

Discussion

Acute or sub-acute lead poisonings following the ingestion of lead-containing foreign bodies are rare in adults (1), but are occasionally observed in children who commonly put things in their mouths. Indeed, lead poisoning has been reported in children after a single ingestion of various metallic objects including a toy necklace, shots and pellets, curtain weights, fishing sinkers, an imported clothing accessory, a heart-shaped charm bracelet, etc (2–8). Usually the child experiences gastrointestinal symptoms, such as abdominal pain and possibly vomiting, less often neurological symptoms, such as irritability. He can be completely asymptomatic as well. A normocytic anemia is frequently noticed shortly after the ingestion. Lead encephalopathy is rarely observed (5–7) but can be fatal (6). Compared to the retention of lead-contaminated objects in the body following a single ingestion, deteriorated lead-based paint and associated lead-contaminated dust and soil in old housing are the most common sources of chronic lead exposure in children, which results in persistently elevated BLL (≥10 μg/dL). Pica is a very well identified risk factor of lead intoxication in children. In the first three years of age, pica may occur in developmentally normal young children and can also occur in children with pervasive developmental disorders (PDD) including autism, where the frequency and intensity of pica do not decrease with age as in children without PDD (9).

However, pica is quite exceptional in adults, where it is usually considered to be a psychiatric condition as in the present case report. Lead poisoning with a very high BLL (391 μg/dL) on admission has been reported after the ingestion of 206 lead bullets by a 45-year-old man with schizophrenia. The patient complained of abdominal pain and had gastrointestinal bleeding. The patient fully recovered after calcium EDTA therapy, GI decontamination, and an oral course of succimer (1). Pica has also been described during pregnancy where it may be associated with increased maternal and fetal BLL (10). Ethnic practices, such as geophagy (or eating earth), have been suggested to be a risk factor. Acute lead poisonings following ceramic lead glaze ingestions during art therapy classes in nursing home residents with dementia have also been described (11). They all had elevated initial BLLs and underwent chelation therapy. One patient with initial BLL at 259 μg/dL experienced lead encephalopathy and died in spite of the chelating treatment combining BAL and EDTA that resulted in decreased BLL. The ceramic glaze did not contain metallic lead but lead oxide whose absorption is greater. Lead intoxication can also be due to accidentally ingested lead bullets retained in the gastrointestinal tract, usually in the appendix, identified by radiography (12–15). In this situation, only moderately elevated to low BLL are noted. Most commonly only a few bullets are seen, but up to 35 lead bullets in a single appendix have been described (15). In a recent case report, a 45-year-old woman with fatigue and gastrointestinal symptoms, but no anemia, had a 6-mm bullet in the ascending colon identified by abdominal X-ray. Her initial BLL was 21 μg/L and DMSA chelation was started. Four months later, her BLL was 55 μg/dL and the bullet was spontaneously released from the colon during an episode of acute gastroenteritis (12). An elective appendectomy was performed to avoid further appendicitis in a child with lead intoxication from a pellet trapped in the appendix. The child experienced gastrointestinal symptoms and his BLL peaked at 23 μg/L (13).

Lead poisoning following ingestion can also be due to other unusual sources, such as glazed earthenware (16–19). One massive intoxication and a few cases of high lead poisoning in two different families were reported from juice or tap water contained in a Greek blue-glazed earthenware jug. The first patient's BLL was 330 μg/dL and DMSA treatment was successful. Each member of the second family had elevated BLL ranging from 16 to 72 μg/dL (16). A review of the literature showed maximal BLLs ranging from 64 to 254 μg/dL suggesting that this source of chronic exposure can lead to massive intoxication and can be avoided provided ceramic producers adhere to European standards (16). Other recently reported unusual sources of lead ingestion include imported lead-contaminated Mexican candies (20), ethnic Mexican remedies (such as greta and azarcon that are used for the treatment of gastrointestinal symptoms [20]), Ayurvedic therapies (21), home-made Chinese medicines (22), Sindoor (product from India used for food coloring (23)), and lead-contaminated spices purchased in foreign countries for various food preparations: swanuri marili, kharchos suneli, and kozhambu (24).

Conclusion

Lead poisoning following the ingestion of lead-containing foreign bodies is particularly rare in adults, while it is sometimes observed in children. The present case of lead poisoning without encephalopathy in an adult resulting from ingestion of lead-containing roofing plates is due to a pica-like behavior. Pica behavior is a well-identified risk factor of lead intoxication in children, but is quite exceptional in adults, where it is usually considered to be a psychiatric condition. The ingestion of lead-containing foreign bodies can lead to high or even very high BLL. GI decontamination combined with chelation therapy may be necessary.

Acknowledgments

Special thanks to Brigitte Tourlière for her assistance in the literature search.