Lead Poisoning Can Be Easily Misdiagnosed as Acute Porphyria and Nonspecific Abdominal Pain

Figure 1

The heme synthetic pathway showing the enzymes mediating formation of delta-ALA, PBG, and the initial porphyrins (uroporphyrinogen), respectively. Lead poisoning and acute porphyria both affect the heme synthetic pathway. In LP, the metal directly inhibits the ALA dehydratase. The result is overproduction of delta-ALA only; PBG normal, reflecting the impaired conversion of delta-ALA to PBG. ALA = aminolevulinic acid; PBG = porphobilinogen; CoA = coenzyme A; Pb⁺⁺ = lead.