PUPPP (pruritic urticarial papules and plaques of pregnancy), also known as polymorphic eruption of pregnancy (PEP), is a rash. It develops in the stretch marks on a belly in late pregnancy or immediately postpartum. Doctors aren’t certain of the cause but have offered a few ideas for why it might happen.
Several factors may play a role. These include hormonal changes during pregnancy, expansion of the abdomen, the presence of a new placenta, and exposure to fetal DNA.
Although the rash causes itching and discomfort, it does not pose a danger to a pregnant person or their baby like other infections during pregnancy can.
The rash usually appears on the stomach, but it can also spread to the thighs, buttocks, and breasts. In rare cases, some people notice a rash on their hands but no PUPPP on the face.
PUPPP usually shows on a person’s belly around 36 weeks into their pregnancy and rarely in early postpartum. There’s not much evidence of it happening in the second or the first trimester. This condition often affects those who are pregnant for the first time and does not recur with subsequent pregnancies. This is because their skin is experiencing this kind of stretching for the first time.
The rash typically starts along the abdomen — sparing the belly button — as pink pimples on top of stretch marks. These bumps aggregate and form plaques that itch. The plaques can spread over the torso to the thighs, buttocks, and breasts. Some people develop PUPPP on the hands, but the face, palms, and soles remain unaffected.
Despite the considerable discomfort of PUPPP, it stays on the top layers of your skin.