For more than two months, a 10-year-old boy in Germany had colicky abdominal pain, constipation, vomiting, and weight loss, and several doctors attributed it to prolonged gastroenteritis. When physicians finally identified lead poisoning, the source still eluded them for weeks. His grandmother eventually found it: a damaged chain used to weigh down curtains, which the boy had been licking for months while playing video games.
The case was published Sept. 9 in Frontiers in Pediatrics by a team from RWTH Aachen University Hospital, RWTH Aachen University's Institute for Occupational, Social and Environmental Medicine and the health department of Germany's Rhein-Erft-Kreis district.
Months of Pain and a Surgery That Found Nothing
The boy had been healthy apart from an appendectomy two years earlier. He lost 7 kilograms, about 15 pounds, over six weeks, until eating became impossible. He had seen several physicians multiple times, and a diagnostic laparoscopy at another hospital found nothing abnormal.
After his transfer to Aachen, pain crises struck several times a day and were not fully controlled even with strong painkillers, including an opioid. During the crises, his blood pressure reached as high as 155/115 mmHg. His behavior and personality changed so much that his family no longer recognized him, the authors wrote, but child and adolescent psychiatrists could not diagnose an isolated somatization disorder.
Tests showed anemia, with hemoglobin as low as 6.4 g/dL, and he needed a blood transfusion once. Three days after admission, he developed blurred vision, episodes of blindness, and headaches. A brain MRI showed changes consistent with either posterior reversible encephalopathy syndrome (PRES), a disorder that can cause headaches and vision problems, or autoimmune encephalitis. Because encephalitis could not be ruled out, doctors gave him immunoglobulin therapy.
A Porphyria Clue Pointed Toward Lead
Suspecting porphyria, a group of disorders that disrupt production of heme, a key component of hemoglobin, doctors tested his urine. A compound called delta-aminolevulinic acid, or ALA, was markedly elevated, while a related marker was only slightly raised.
That pattern fit ALA dehydratase deficiency porphyria, an inherited disorder so rare that only eight cases have been reported worldwide, the authors wrote. It also fits lead poisoning, which is uncommon but far more likely, because lead blocks the enzyme that normally processes ALA.
Other clues lined up, including speckled red blood cells known as basophilic stippling, urine that darkened after sun exposure, and discoloration along his gums.
His blood lead level came back at 580.7 micrograms per liter, more than 26 times the laboratory's reference value of 22 micrograms per liter for boys ages 3 to 11. That equals about 58 micrograms per deciliter. For comparison, the CDC's blood lead reference value is 3.5 µg/dL, a benchmark based on U.S. children ages 1 to 5 that identifies children with more lead in their blood than most. The CDC says doctors may recommend medication to remove lead at levels of 45 µg/dL or higher.
Chelation therapy, which binds lead so the body can excrete it, resolved his symptoms within days.
The authors wrote that clinically obvious lead poisoning has become uncommon in high-income countries, which can delay recognition because many clinicians have little experience with it. Globally, the problem is far larger. The authors cite a UNICEF and Pure Earth report estimating that up to 800 million children, about one-third of children worldwide, have blood lead levels of at least 5 µg/dL.
The Curtain Weight He Licked While Gaming
Finding the source proved harder. Close relatives had normal lead levels, suggesting the boy alone was affected. The local health department inspected his school and home, and water samples showed only negligible lead.
After discharge, his blood lead stayed above 500 micrograms per liter, pointing to ongoing exposure. Seven weeks into chelation, his grandmother noticed a damaged chain at home, used as a curtain weight, with lead-based, pearl-like elements. The boy had been regularly licking and mouthing it for months while gaming and kept doing so during treatment. Laboratory analysis confirmed that the weights contained a significant amount of lead.
Curtain weights are a known but easily overlooked hazard. The National Library of Medicine's MedlinePlus encyclopedia lists them among lead sources along with lead bullets and fishing sinkers, and Poison Control also warns that curtain weights may contain lead.
The authors argued that exposure investigations often focus on established routes such as water, paint, soil, and lead brought home from work. Habits like repeatedly mouthing household objects may stay hidden unless clinicians ask directly, including about object chewing and gaming routines.
Lead Stored in Bone Keeps the Risk Going
Once the chain was removed, the boy's lead levels fell, but slowly. The team's analysis found a two-phase decline, with an initial blood half-life of about half a year followed by a slower phase of about two years. Both are far longer than the roughly 30 to 35 days expected after a single exposure.
The researchers explained that in chronically exposed children, bone can hold more than 70% of the body's lead and release it back into the bloodstream. The World Health Organization likewise notes that lead is stored in teeth and bones, where it can accumulate over time. Chelation stopped after about a year, when his level had dropped to 304.1 micrograms per liter.
He has been symptom-free for 12 months and is developing appropriately for his age, the authors reported. Still, they cautioned that possible long-term effects on growth, intelligence or fertility cannot yet be estimated, because lead stored in bone may have a half-life of more than 20 years.
The CDC advises parents who are concerned about lead exposure to contact their child's health care provider about a blood lead test.
Key Questions Answered
What caused the boy's illness?
Severe lead poisoning. His blood lead level was 580.7 micrograms per liter, more than 26 times the laboratory's reference value for boys his age.
What was the source of the lead?
A damaged curtain weight chain with lead-based, pearl-like elements. He had been licking and mouthing it for months while playing video games.
Why was the diagnosis so difficult?
His symptoms were first blamed on prolonged gastroenteritis, and his case raised questions about a psychiatric condition, a rare porphyria, PRES, and autoimmune encephalitis. The authors also noted that lead poisoning has become uncommon in high-income countries.
How was he treated?
He received chelation therapy, which helps the body remove lead. His symptoms resolved within days, and treatment continued for about a year.
Can lead poisoning have lasting effects?
Yes. Lead can remain stored in bone for many years, and the authors said possible long-term effects on growth, intelligence, or fertility cannot yet be estimated.
What should parents do if they are worried about lead?
The CDC recommends contacting a child's health care provider about a blood lead test. Parents can also check for household items that may contain lead, such as curtain weights and fishing sinkers.
