- A family of uncommon genetic disorders associated w/abnormalities in heme biosynthesis in the liver
- Dysfunctional or lower than normal levels of enzyme → accumulation of precursor proteins
- Different symptoms/presentations based on which enzymes deficient → build up of different precursor proteins
- AIP is most common of the acute porphyrias
- Interestingly, most patients w/the genetic defect don't manifest the disease - indicating that other factors contribute
- Attacks triggered by meds (multiple), starvation/decreased caloric intake (low carbs), smoking, etoh
- + family history
- Episodic bouts of otherwise unexplained symptoms related to neuro-toxicity of built up precursor protein
- Anxiety and insomnia often precursor sx prior to attack
- During attack, symptoms include: severe abd pain, agitation/confusion, nausea, vomiting, fatigue, limb pain, motor and sensory neuropathy
- Often history of prior unexplained episodes, leading to concern about malingering or drug seeking
- Duration of symptoms (typically < 1-2w) and time between attacks vary
- Neurological deficits (e.g. foot or wrist drop) resolve w/time (up to 1y)
- Episodic htn, tachycardia
- Generalized muscle weakness
- Abdominal pain w/normal exam
- Sensory loss and/or motor weakness that follows peripheral nerve pattern
- Often hyponatremia that isn't otherwise explained
- Elevated urine porphobilinogen, in particular during an attack