Introduction

Lead poisoning is a toxic condition caused by lead accumulation in the body. Although environmental exposure has fallen following restrictions on the use of lead-containing materials, it remains an important, preventable cause of morbidity, particularly in children. Young children are especially vulnerable as they absorb up to four to five times more lead than adults from the same ingested dose [1]. Frequent age-appropriate hand-to-mouth and object-to-mouth behaviours, which start at around six months of age and roughly start to decline from ages three and upwards [2], further increase the risk of exposure to lead-containing materials. Additional risk factors include pica - the compulsive, habitual consumption of non-food items - and nutritional deficiencies, particularly iron deficiency, which increases gastrointestinal lead absorption.

It can be difficult to detect lead poisoning in children because it is frequently asymptomatic or presents with non-specific symptoms. As lead accumulates in multiple organs, particularly the brain and bones, the clinical manifestation of lead poisoning is varied; it ranges from gastrointestinal symptoms such as abdominal pain, vomiting and constipation, to neurological manifestations including behavioural change, distal neuropathies, and, in severe cases, encephalopathy [3].

There is no recognised safe blood lead concentration in children. Confirmation of cases requires venepuncture for whole blood levels. Evaluation should also increase screening for other nutritional deficiencies, particularly iron deficiency, and investigation of potential environmental sources of exposure. Plain radiographs may demonstrate metaphyseal ‘lead lines’ in children with significant exposure, suggestive of arrested bone growth [3].

Treatment involves identification and removal of the source of exposure and, in cases of significant toxicity, chelation therapy. Ongoing neurodevelopmental follow-up may be required as neurological injury may be irreversible despite treatment.

We report the case of a two-year-old child with asymptomatic lead poisoning identified through targeted blood lead screening prompted by pica and iron deficiency anaemia.