Differential Diagnosis for a 16-Week Pregnant Patient Experiencing a Miscarriage

The patient's symptoms and allegations of poisoning require a thorough investigation into potential substances that could cause a miscarriage, are tasteless, odorless, and can be dissolved in tea. The following differential diagnoses are categorized based on their likelihood and potential impact:

• Single Most Likely Diagnosis

  • Misoprostol: This medication is known for its use in medical abortions. It is tasteless and odorless, can be dissolved in liquids like tea, and if ingested, could induce a miscarriage. Given the context of the patient's allegations and symptoms, misoprostol is a plausible cause.

• Other Likely Diagnoses

  • Methotrexate: Although not typically described as tasteless and odorless, methotrexate is used in medical abortions and can cause a miscarriage. Its use in this context, especially if the patient has been given it without her knowledge, could fit the scenario.
  • Quinine: Historically used for abortion, quinine can be lethal in high doses and could potentially be used to induce a miscarriage. However, its bitter taste might make it less likely to be undetected in tea.

• Do Not Miss Diagnoses

  • Ricin: A highly toxic substance that can be odorless and tasteless. While extremely rare and unlikely, the ingestion of ricin could lead to severe illness and death, making it crucial not to miss this diagnosis.
  • Cyanide: Another highly toxic substance that can be odorless and tasteless in certain forms. Cyanide poisoning is rapidly fatal, and any suspicion of its ingestion warrants immediate medical attention.

• Rare Diagnoses

  • Abrin: Similar to ricin, abrin is a highly toxic substance derived from plants. It is extremely potent and could cause severe illness or death if ingested, even in small amounts.
  • Other Plant Toxins: Various plants contain toxins that could potentially induce a miscarriage if ingested. Examples include pennyroyal and blue cohosh, though these are less likely to be completely tasteless and odorless when dissolved in tea.

Each of these substances has the potential to cause severe harm or induce a miscarriage, and their tasteless and odorless nature could facilitate their administration without the patient's knowledge. The investigation should prioritize substances that are both accessible and have a known history of use in attempts to induce abortion or cause harm.