Differential Diagnosis for Rash on Lower Back and Torso in a 32-Week Pregnant Woman
- Single most likely diagnosis
- Pregnancy-related eczema (atopic eruption of pregnancy): This condition is common in pregnancy, especially during the second and third trimesters. The symptoms of itchy rash on the torso, including the lower back, align with the presentation of pregnancy-related eczema. The absence of any underlying medical conditions or medication use also supports this diagnosis.
- Other Likely diagnoses
- PUPPP (Pruritic Urticarial Papules and Plaques of Pregnancy): This is a common skin condition in pregnancy, characterized by an itchy rash that typically starts on the abdomen and can spread to other areas, including the lower back and torso.
- Contact dermatitis: Although less common in pregnancy, contact dermatitis could be a consideration if the patient has been exposed to new soaps, laundry detergents, or other potential allergens.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Pemphigoid gestationis: A rare autoimmune skin disorder that occurs during pregnancy, characterized by a blistering rash. Although it is less common, missing this diagnosis could lead to severe consequences for both the mother and the fetus.
- Intrahepatic cholestasis of pregnancy (ICP): This condition is characterized by intense itching, often without a rash, but a rash can sometimes be present. ICP can lead to serious complications for the fetus if left untreated.
- Rare diagnoses
- Impetigo herpetiformis: A rare skin condition that occurs during pregnancy, characterized by pustular lesions. It is associated with an increased risk of complications for both the mother and the fetus.
- Psoriasis: Although not typically associated with pregnancy, psoriasis could be a consideration if the patient has a history of the condition or if the rash does not respond to typical treatments for pregnancy-related eczema or other conditions.