Page 146 - The Netter Collection of Medical Illustrations - Integumentary System_ Volume 4 ( PDFDrive )

Plate 4-61 Integumentary System

PRURITIC URTICARIAL PAPULES
AND PLAQUES OF PREGNANCY

Pruritic urticarial papules and plaques of pregnancy
(PUPPP), also known as polymorphous eruption of
pregnancy (PEP), is the most common dermatosis asso-
ciated with pregnancy. The name describes the variable
appearance that the rash can take. Idiopathic in nature,
it is seen most commonly during an expectant mother’s
first pregnancy. It has been shown to have no bearing
on pregnancy outcome or on the fetus or newborn. It
is diagnosed on clinical grounds and rarely biopsied.
There are no associated laboratory abnormalities. The
classic history and variable morphology of the rash are
characteristic.
Clinical Findings: PUPPP occurs during the late
third trimester of pregnancy or has its onset soon after
delivery. The rash almost always begins within the
striae distensae of the abdomen. Small urticarial papules
and plaques begin to form within the striae. They are
extremely pruritic and cause significant discomfort. As
the name implies, the rash can have a polymorphous PUPPP on
nature. Papules, plaques, macules, and even small vesi- abdomen
cles have been described. The rash may spread from the within striae
abdomen to other regions of the body. PUPPP has been
described to occur more commonly during the first
pregnancy with a male fetus. The reasons for this are
unknown. The rash spontaneously remits after delivery,
in most cases within 2 to 4 weeks. Those patients with
onset after delivery typically have a shorter course, with
1 week of severe itching followed by remission soon Herpes gestationis. Also known as bullous
afterward. PUPPP typically does not recur in subse- pemphigoid of pregnancy. Pruritic bullae
quent pregnancies. PUPPP also does not flare when develop on a background of erythematous or
birth control medications are started, as does herpes urticarial-appearing skin.
gestationis.
The main differential diagnosis is between PUPPP
and prurigo gestationis. Prurigo gestationis has no
primary lesions and manifests as diffuse itching with
excoriations. Liver function enzymes may be elevated
in this condition. Prurigo gestationis is associated with
an increased risk for prematurity. Scabies infection can
also be highly pruritic and can be considered in the
differential diagnosis. Scabies is easily diagnosed with
a scraping and microscopic evaluation of a burrow.
Scabies can have its onset at any time during a preg-
nancy, and urticarial papules and plaques within striae
are not typically seen. If they are seen, they are not as
numerous or uniform in appearance as the lesions of
PUPPP. Herpes gestationis, also known as pemphigoid
gestationis or bullous pemphigoid of pregnancy, is the
most severe of all the pregnancy-associated rashes. It
can begin as urticarial red plaques on the abdomen and
then spread to other regions. Compared with PUPPP,
it tends to occur earlier in the pregnancy. The biggest Herpes gestationis (pemphigoid gestationis) Immunofluorescence. Immunofluorescence studies
differentiating point is that the rash of herpes gestatio- (H&E stain). Prominent subepidermal bulla show linear staining of C3 along the basement
nis will begin to blister: Small vesicles form and quickly formation is seen along the specimen. Separation membrane zone in herpes gestationis.
coalesce into larger bullae. Bullae are never seen in is caused by antibodies against the BP180 protein,
PUPPP. Herpes gestationis is caused by maternal anti- which leads to bulla formation.
body formation against hemidesmosomal antigens.
Titer levels can be measured, and the most commonly
found antibody is against the 180-kd bullous pemphi-
goid antigen (BP180). There is a risk of prematurity
and low birth weight with this rash. Oral corticosteroids is more common in multiple-birth pregnancies. The Treatment: The main treatment for PUPPP is
are often needed to keep herpes gestationis under exact roles played by skin distention, hormonal changes, to give supportive care and to try to suppress the
control. The rash remits after delivery but tends to and interactions with the immune system in the patho- itching symptoms. There are no ill effects on the
recur during subsequent pregnancies, and it can flare genesis of PUPPP are being studied. fetus, and expectant mothers can be given topical
when an affected patient starts taking birth control Histology: Histological findings of PUPPP biopsy medium- or high-potency corticosteroids to help
medications. specimens are nonspecific; there is a superficial and decrease the itching. Occasionally, antihistamines such
Pathogenesis: The etiology is unknown. PUPPP is deep perivascular lymphocytic infiltrate. Occasional as diphenhydramine are also needed to control the
most commonly seen in first pregnancies and possibly eosinophils are seen, with some dermal edema. itching.

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