Introduction
PUPPP rashes are the most common pregnancy skin condition. They appear in approximately one in every 160 pregnancies. The PUPPP stands for pruritic urticarial papules and plaques of pregnancy rash. It is also known as polymorphic pregnancy eruption or toxemic pregnancy rash. It is an itchy, bumpy rash that appears in the stretch marks of the abdomen during the last three months of pregnancy. It can spread to other body parts, including the back, breasts, arms, and buttocks. The rash usually starts with the formation of papules or tiny raised bumps on the skin that can grow to one cm in diameter. The small papules eventually fuse into larger plaques on the skin, some of which can be more than one cm in diameter. The rash usually appears between 35 and 36 weeks of pregnancy. Less frequently, the rash may appear shortly after the baby is delivered (during the postpartum period). PUPPP is uncomfortable, but it is safe for both the mother and the baby. It usually subsides after the baby is born.
Other names of PUPPP rashes include;
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Nurse's late-onset prurigo.
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Bourne's toxemic rash of pregnancy.
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Toxic erythema of pregnancy.
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Polymorphic eruption of pregnancy.
What Causes PUPPP Rashes?
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The precise causes of PUPPP are still unknown; however, several theories have been proposed. The most popular theories contend that the rash appears in areas where the skin is stretched, such as the abdomen, which expands dramatically during pregnancy. The PUPPP rash could be caused by increased vascularity and damaged collagen in the skin, which could trigger an inflammatory immune response. Notably, in approximately 90% of cases, the rash appears near areas of damaged connective tissue (i.e., stretch marks). The following observations lend support to the stretch mark theory:
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Most cases begin within the last three months, particularly the last five weeks when the stretching is greatest.
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The rash usually begins with stretch marks around the umbilicus, where the abdomen is most stretched.
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It occurs 14 times more likely in triplet pregnancies than twin pregnancies (2.9%).
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Hormonal changes during pregnancy may also play a role in developing the PUPPP rash. Progesterone levels, for example, are elevated in many PUPPP rash patients.
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Fetal DNA can act as a trigger for the development of PUPPP. There are theories that PUPPP is caused by peripheral deposition of fetal DNA (especially of male fetuses) on the mother's skin, primarily during the third trimester. The mechanism by which lesions spread throughout the body is also unknown. The rash rarely appears in later pregnancies, possibly due to a stronger immune response.
What Are the Characteristics of a PUPPP Rash?
The rash usually appears in the last few weeks of pregnancy, during the third trimester. However, approximately 15 % of women with PUPPP report that it began immediately after delivery. PUPPP rashes resemble hives in appearance and feel. The following are some symptoms of PUPPP:
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Scattered, itchy bumps appear upon and near the stretch marks, sometimes forming raised patches of skin or a rash.
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The rash progresses to the thighs, buttocks, breasts, and arms.
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The rash is not visible in the area around the belly button.
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The bumps or patches may appear pink or red on skin with less melanin.
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The bumps or patches on skin with more melanin may be the same color as the skin or a darker skin tone.
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The itching from the rash makes it difficult to focus on daily activities and disrupts sleep.
How Is PUPPP Diagnosed?
PUPPP is diagnosed primarily through a thorough physical examination of the entire body to assess skin irritation and review the individual's medical history. Notably, PUPPP target-like lesions may mimic medication reactions. Therefore, a thorough history review can reveal whether or not new medications were recently started. Routine blood tests are usually within normal limits. To rule out other skin conditions, additional, more particular tests, such as serum analysis or skin biopsies, can be performed (e.g., pemphigoid gestationis, the infection from herpes during pregnancy). In addition, the doctor may order additional blood tests to rule out other infections, such as:
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Complete blood count.
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Liver function test.
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Serum cortisol.
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Serum human choriogonadotropin (HCG).
The final diagnosis is frequently based on exclusion. However, if it is unclear whether the rash is PUPPP or PG, the doctor may order a biopsy to test a skin sample. This is known as a direct immunofluorescence test.
How Is PUPPP Treated?
There is no curative treatment for PUPPP. It lasts four to six weeks. It disappears on its own within a few days to a few weeks after the baby is born. Medications and home remedies can help relieve symptoms while rashes subside. PUPPP treatment varies depending on the individual's symptoms and the severity of the rash.
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Most affected individuals find that topical steroid creams (e.g., Mometasone furoate 0.1%) and oral antihistamines provide adequate relief (e.g., Diphenhydramine).
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Antihistamines of the first and second generations (e.g., Diphenhydramine, Chlorpheniramine) are generally safe during pregnancy and can be used as an adjunct therapy to relieve pruritus.
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Regularly applying moisturizing creams, cool baths, and light cotton clothing provides additional symptomatic relief.
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Recently, intramuscular injection of autologous blood therapy (injection of one's own blood) has been proposed as a possible alternative treatment, particularly in postpartum PUPPP.
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In some cases, a doctor may prescribe an oral steroid to relieve the condition's pain and itching. However, these are typically prescribed for women experiencing severe symptoms of the condition, such as intense itching and discomfort.
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A short course of oral steroids (e.g., Prednisone) can be helpful for more severe irritations that can disrupt the individual's sleep.
Conclusion
PUPPP rash (pruritic urticarial papules and plaques of pregnancy) is an itchy rash that appears during pregnancy. It begins with the formation of small, red, swollen papules, which may eventually merge into larger plaques. PUPPP typically appears near stretch marks, particularly near the belly button, and can spread to the trunk and extremities within a few days. Though the underlying causes are unknown, PUPPP has been proven to be neither contagious nor harmful to the fetus. While PUPPP is annoying, there is a light at the end of the tunnel. PUPPP rashes disappear after pregnancy and do not usually leave scars. A doctor can assist in making a diagnosis and suggesting ways to manage the itching.
