Pruritic urticarial papules and plaques of pregnancy (PUPPP), known in United Kingdom as polymorphic eruption of pregnancy (PEP), is a chronic hives-like rash that strikes some women during pregnancy. Some skin changes are known to occur in people who are pregnant while other skin conditions, or dermatoses, that people have prior to getting pregnant will become altered or symptoms will increase. Pruritic urticarial papules and plaques of pregnancy (PUPPP) is one of many skin conditions that is specific to pregnancy and occurs in about 1 in every 160 (0.625%) of pregnancies.It presents no long-term risk for either the woman or fetus as there is no statistical increase of risk of premature labor or fetal loss, despite frequently severe pruritus.PUPPP usually first appears on the abdomen and often spreads to the legs, feet, arms, chest, and neck. The face is usually not affected. Skin distension (stretching) is thought to be a possible trigger for PUPPP as it most commonly affects primigravida (women in their first pregnancy), those with large fundal measurements (distance from the pubic bone to the top of the uterus) and/or those who are carrying large babies or multiples. The papules and plaques often first appear within stretch marks before changing appearance and spreading to other areas of the body. It is important that those who are pregnant heavily consider the recommendations of their full healthcare team.
With this increase in progesterone, it causes there to be an increased level of progesterone receptors present eliciting an immune reaction seen by skin lesions in PUPPP. With multiple gestations, there is an increase in sex hormones that has been seen those with the condition such as an increase in progesterone as previously discussed but also higher levels of estradiol. Currently evidence is weak in the role that sex hormones play when contributing to PUPPP where further research is needed. Immunological Causes
Inflammatory Mediated
From those with PUPPP, it has been seen from an immunohistology profile which is used to determine the of tissue components present within an individual via the use of antibodies, that there are certain immune cells that are in greater amount compared to that of those without PUPPP. Immunohistology profile have shown cells consistent with a delayed hypersensitivity with T helper cell infiltrates, dendritic cells and epidermal Langerhans cells.It has been hypothesized that PUPPP appears in response to fetal antigens that circulate throughout the body. For example, a study showed that fetal male DNA was found within the lesions of the mothers skin which was thought to be caused by the fetal cells seen in the mothers blood throughout pregnancy. Autoimmune
Although this condition has not been determined as an autoimmune condition, from a single study it has been seen that Immunoglobulin M (IgM) deposition at the dermal-epidermal membrane has been associated with a variety of dermatosis including PUPPP.