Differential Diagnosis for Itching in the Third Trimester of Pregnancy
Single Most Likely Diagnosis
- Intrahepatic Cholestasis of Pregnancy (ICP): This condition is characterized by itching and elevated liver enzymes, typically presenting in the third trimester. It is the most common cause of itching during pregnancy, especially in the absence of a rash.
Other Likely Diagnoses
- Pemphigoid Gestationis: An autoimmune skin disorder that causes itching and blistering, typically starting around the navel and spreading to other areas of the body.
- Pruritic Urticarial Papules and Plaques of Pregnancy (PUPPP): A common skin condition in pregnancy, characterized by itchy, raised patches on the skin, often starting in the abdominal area.
- Dry Skin (Xerosis): Hormonal changes during pregnancy can lead to dry skin, which may cause itching.
- Allergic Reactions: Allergies to foods, medications, or environmental factors can cause itching during pregnancy.
Do Not Miss Diagnoses
- Cholestasis due to Other Liver Diseases: Conditions like primary biliary cirrhosis or viral hepatitis can cause cholestasis and itching, and are crucial to diagnose due to their potential impact on both mother and fetus.
- Obstetric Cholestasis with Underlying Liver Disease: Pre-existing liver conditions can worsen during pregnancy, leading to severe itching and potential complications.
- Acute Fatty Liver of Pregnancy: A rare but serious condition that can cause itching, among other symptoms, and requires immediate medical attention.
Rare Diagnoses
- Polycythemia Vera: A rare blood disorder that can cause itching due to increased histamine release, though it is uncommon in pregnancy.
- Thyroid Disorders: Both hyperthyroidism and hypothyroidism can cause itching, though they are less common causes in the context of pregnancy.
- Mastocytosis: A condition characterized by an accumulation of mast cells in the skin, which can cause itching, though it is rare and not typically associated with pregnancy.