Signs and symptoms: a deeper look1,2

Severe abdominal pain
Usually unremitting (for hours or longer) and poorly localized but can be cramping. Neurologic in origin and rarely accompanied by peritoneal signs, fever, or leukocytosis. Nausea and vomiting often accompany abdominal pain.
Urine discoloration
Urine darkening (port wine to strawberry sap) on standing and/or typically enhanced by sun exposure (as result of polymerization of urinary PBG in excess to porphyrins and other pigments).
Paresis
May occur early or late during a severe attack. Muscle weakness usually begins proximally rather than distally and more often in the upper than lower extremities.
Convulsions
A central neurologic manifestation of porphyria or due to hyponatremia, which often results from syndrome of inappropriate antidiuretic hormone secretion or sodium depletion.
Neurologic pain
Pain may begin in the chest or back and move to the abdomen. Extremity pain indicates involvement of sensory nerves, with objective sensory loss reported in 10‑40% of cases.
Mental symptoms
May range from minor behavioral changes to agitation, confusion, hallucinations, and depression.
Severe abdominal pain Usually unremitting (for hours or longer) and poorly localized but can be cramping. Neurologic in origin and rarely accompanied by peritoneal signs, fever, or leukocytosis. Nausea and vomiting often accompany abdominal pain.
Urine discoloration Urine darkening (port wine to strawberry sap) on standing and/or typically enhanced by sun exposure (as result of polymerization of urinary PBG in excess to porphyrins and other pigments).
Paresis May occur early or late during a severe attack. Muscle weakness usually begins proximally rather than distally and more often in the upper than lower extremities.
Convulsions A central neurologic manifestation of porphyria or due to hyponatremia, which often results from syndrome of inappropriate antidiuretic hormone secretion or sodium depletion.
Neurologic pain Pain may begin in the chest or back and move to the abdomen. Extremity pain indicates involvement of sensory nerves, with objective sensory loss reported in 10‑40% of cases.
Mental symptoms May range from minor behavioral changes to agitation, confusion, hallucinations, and depression.

References:

  1. Anderson KE, Bloomer JR, Bonkovsky HL, et al. Recommendations for the Diagnosis and Treatment of the Acute Porphyrias. Ann Intern Med 2005;142:439‑450.
  2. Ventura P, et al, A challenging diagnosis for potential fatal diseases: Recommendations for diagnosing acute porphyrias. Eur J Intern Med 2014, https://dx.doi.org/10.1016/j.ejim.2014.03.011