Differential Diagnosis for Rash in Pregnancy
- Single most likely diagnosis
- Polymorphic eruption of pregnancy (PEP): This is the most common skin condition in pregnancy, occurring in about 1 in 160 pregnancies. It is characterized by an itchy rash that typically starts in the abdominal striae and spreads to other areas.
- Other Likely diagnoses
- Pemphigoid gestationis: An autoimmune skin disorder that occurs during pregnancy, causing blistering lesions. It is less common than PEP but still a significant consideration.
- Pruritic urticarial papules and plaques of pregnancy (PUPPP): Similar to PEP, this condition is also itchy and starts in the abdominal striae, but it tends to occur earlier in pregnancy.
- Atopic eruption of pregnancy: This encompasses a range of skin conditions, including eczema, that can flare up or first appear during pregnancy due to hormonal changes.
- Do Not Miss
- Pemphigus: A rare but serious autoimmune disease that causes blistering of the skin and mucous membranes. It can be life-threatening if not treated promptly.
- Stevens-Johnson syndrome: A severe skin and mucous membrane disorder, usually a reaction to medication or infection. It is rare but can be fatal if not recognized and treated early.
- Intrahepatic cholestasis of pregnancy (ICP): While not primarily a skin condition, ICP can cause severe itching without a rash, and it has significant implications for fetal health.
- Rare diagnoses
- Impetigo herpetiformis: A rare skin condition that resembles pustular psoriasis and can occur during pregnancy. It is associated with significant maternal and fetal morbidity if not treated.
- Acute fatty liver of pregnancy: Although primarily a liver condition, it can present with skin manifestations such as jaundice and has a high risk of maternal and fetal complications if not promptly diagnosed and managed.