Differential Diagnosis for Pregnancy Rash
- Single most likely diagnosis
- Polymorphic eruption of pregnancy (PEP): This is the most common skin condition associated with pregnancy, occurring in about 1 in 160 pregnancies. It typically presents in the third trimester with intense itching and a rash that starts in the abdominal striae and can spread to other areas.
- Other Likely diagnoses
- Pruritic urticarial papules and plaques of pregnancy (PUPPP): Similar to PEP, PUPPP is a common skin condition in pregnancy, characterized by itchy, raised patches on the skin, often starting in the abdominal area.
- Atopic eruption of pregnancy: This encompasses a range of skin conditions including eczema (atopic dermatitis), which can flare during pregnancy due to hormonal changes.
- Pemphigoid gestationis: An autoimmune skin disorder that occurs during pregnancy, characterized by blistering of the skin, usually starting around the navel and spreading to other parts of the body.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Pemphigus: A group of autoimmune diseases that cause blistering of the skin and mucous membranes. Although rare, it can be life-threatening if not treated promptly.
- Stevens-Johnson syndrome/toxic epidermal necrolysis: Severe skin and mucous membrane disorders usually caused by an adverse reaction to medications. These conditions are rare but can be fatal.
- Rare diagnoses
- Intrahepatic cholestasis of pregnancy (ICP): A condition characterized by severe itching without a rash, caused by a reduction in the flow of bile. It's a rare condition but can have significant implications for the fetus if not managed properly.
- Prurigo of pregnancy: A rare condition presenting with extremely itchy nodules on the skin, often on the arms, legs, and buttocks. The exact cause is unknown, but it is thought to be related to hormonal changes during pregnancy.