Differential Diagnosis for Itchy Red Nodules in 30 Weeks Gestation
Single Most Likely Diagnosis
- Polymorphic Eruption of Pregnancy (PEP): This condition is the most common dermatosis in pregnancy, occurring in approximately 1 in 160 pregnancies. It typically presents in the third trimester with itchy, red, papular lesions, often starting in the abdominal striae and spreading to other areas. The timing and description of the symptoms align closely with PEP.
Other Likely Diagnoses
- Atopic Eruption of Pregnancy: This includes atopic dermatitis (eczema), which can flare during pregnancy due to hormonal changes. It presents with itchy, red, and scaly lesions.
- Pemphigoid Gestationis: An autoimmune blistering disease that occurs during pregnancy, characterized by itchy, urticarial plaques that can evolve into blisters. It typically starts around the navel and spreads.
- Prurigo of Pregnancy: A condition presenting with extremely itchy nodules or papules, often on the arms, legs, and abdomen.
Do Not Miss Diagnoses
- Intrahepatic Cholestasis of Pregnancy (ICP): Although ICP primarily presents with severe itching without a primary rash, it can sometimes be associated with excoriations or secondary skin changes due to scratching. It's crucial to consider ICP due to its potential to cause fetal distress and other complications.
- Pustular Psoriasis: A rare but serious condition that can present with itchy, red, and pus-filled bumps. It requires prompt treatment to prevent complications.
Rare Diagnoses
- Pruritic Urticarial Papules and Plaques of Pregnancy (PUPPP): Although not as rare as some other conditions, PUPPP is less common than PEP and presents with itchy, red, and urticarial lesions, often starting in the abdominal striae.
- Dermatosis due to other systemic diseases: Such as thyroid disorders or autoimmune diseases, which can present with skin manifestations during pregnancy, including itchy red nodules.