Cryptogenic Abdominal Pain: Recognizing False Leads

BACKGROUND Lead toxicity is a rare yet serious condition which can be difficult to diagnose due to vague presenting symptoms. Other pathologies can also mimic the symptoms of chronic lead toxicity, making an already difficult diagnosis more challenging. There are multiple environmental and occupational contributors to lead toxicity. A thorough history and an open differential is the key to diagnosing and treating this rare disease. With increasing diversity of our patient population, we should keep an open differential, as the epidemiological features of presenting concerns have diversified as well. CASE REPORT A 47-year-old woman presented with persistent nonspecific abdominal pain despite extensive prior work, surgeries and a prior diagnosis of porphyria. This patient was eventually diagnosed as having lead toxicity when her most recent work-up for abdominal pain revealed no urine porphobilinogen and a high lead level. The cause of lead toxicity was attributed to be an eye cosmetic called "Surma", which can have variable lead levels. Chelation therapy was advised for the patient. CONCLUSIONS It is important to recognize the difficulty in this challenging diagnosis for nonspecific abdominal pain and to eliminate the mimickers. This case is interesting because the patient was initially diagnosed with porphyria, highlighting how heavy metals, lead in this case, can lead to a false-positive diagnosis of porphyria. Accurate diagnosis requires awareness of the role of urine porphobilinogen, checking lead levels, and an open differential. This case also emphasizes the importance of avoiding anchor bias to make a timely diagnosis of lead toxicity.