Early in my career, I learned that asking a new patient about their past history can avoid unnecessary tests or referrals.
I recall a patient who I saw early on in my internship, who had gotten a small foreign body in his eye. When I examined him I noted that his pupil was abnormal in appearance and his vision was poor in that eye. I quickly got an ophthalmologist on the phone to make a rapid referral.
The ophthalmologist agreed to stay late and the patient made the journey across town to see him. Later that day, I got a call from the ophthalmologist. He told me that if I had gotten a better history from the patient I could have avoided referring the patient. It turns out the patient had injured that eye previously, many years ago, and had a pupil deformity with blurred vision ever since.
So lesson learned. Always determine if the problem is new versus chronic.
On another occasion sometime after this, I saw a young woman with abdominal pain and numbness in her legs. This was not going to be easy to figure out. It didn’t make sense. There didn’t seem to be any cause for it and it didn’t fit any typical pattern of disease that causes abdominal pain.
Before I went down the rabbit hole of ordering labs, CT scans, etc., I asked her if she had ever had these symptoms before. She replied yes. I asked what she was told it was the last time. She replied, “Acute Intermittent Porphyria.”
Wow, that is rare! The simple question, “Have you ever had this before?” saved a lot of time and unnecessary testing.
Acute Intermittent Porphyria (AIP) is a rare genetic disorder affecting the heme (a form of iron our body needs) biosynthesis pathway with a prevalence of 1 in 100,000. It is inherited in an autosomal dominant pattern, meaning a single copy of the mutated gene can cause the disorder. Despite this mode of inheritance, AIP exhibits low penetrance; many individuals carrying the mutation remain asymptomatic throughout their lives. That explains why I have only ever seen one case.
This condition results from an enzyme deficiency that disrupts the heme production pathway. As a result, neurotoxic precursors accumulate and can cause a range of symptoms, primarily affecting the nervous system. Patients who carry the gene for this disease may develop symptoms if triggered by medications, hormonal changes, fasting or stress.
Typical symptoms include severe abdominal pain that is often diffuse and without a clear cause. Neurological symptoms range from peripheral neuropathy, characterized by muscle weakness and sensory disturbances, to central nervous system effects like seizures, confusion, or hallucinations.
Symptoms may include tachycardia, and hypertension as well as nausea, vomiting, and constipation. During acute attacks, urine may appear reddish or brown due to the excretion of porphyrin precursors.
Treatment typically consists of avoiding triggers, pain management, and monitoring for complications. One of the in-hospital treatments used is high-dose IV glucose, as this helps suppress the production of porphyrin precursors. Heme therapy can also be helpful.
My preceptor at the time asked me how I made such a rare diagnosis so fast. I was briefly tempted to feign brilliance, but I confessed that I just asked the patient if she ever had it before. He replied, “That’s good, no point in reinventing the wheel.”
