Daily Exam Question April 20, 2014 - OB
Which of the following is least likely associated with pruritic urticarial papules and plaques of pregnancy?
Pg.1094 Gabbe 6th Ed. Normal and Problem pregnancy
Rash is polymorphous eruption starts in the abdominal striae and shows periumblical sparing
PUPPP also is the most common specific dermatoses of pregnancy. Occurs 1 in 300 pregnancies. It occurs classically in primagravidas in the mid to late third trimester, and has been associated with a slight predominance of male babies. Lesions typically being in the abdominal straiae and spare the periumilical region.It can be difficult to characterize as the eruption is polymorphous and can include urticarial and occasionally vesicular purpuric polycylci or targetoid lesions reminiscent of erythema multiformed or herpes gestationis. Although lesions can spread over the trunk and extremities they usually spare the palms and soles, and involvement of the face is very unusual. Tx of mild puppp can be treated with antipruritic topical medications topical steriods and oral antihistamines.
Intrahepatic Cholestasis of Pregnancy Generalized pruritus occurs secondary to intrahepatic cholestasis of pregnancy (ICP), the most common pregnancy-induced liver disorder. The condition manifests itself with jaundice (intrahepatic jaundice of pregnancy or obstetric cholestasis) or without (pruritus gravidarum). ICP is common in Chile, Bolivia, and Scandinavia and less prevalent in Europe (0.1 to 1.5 percent) and United States (<0.1 percent). It can recur in subsequent pregnancies or with oral contraceptives. There is a family history in half of the cases and associations with multiple gestation pregnancy and hepatitis C. ICP may be preceded by a urinary tract infection.
Itching may precede the laboratory abnormalities of the condition, affecting the palms and soles and extending to the legs and abdomen. Excorations due to scratching are invariably seen but no primary skin lesions. Mild nausea and discomfort in the upper right quadrant may accompany the pruritus. Mild jaundice (20 percent) can develop 2 to 4 weeks of the onset of pruritus and may be associated with subclinical steatorrhea and increased risk of hemorrhage. Up to 50 percent of patients develop darker urine and light-colored stools. Elevation of serum bile acids is the most sensitive marker of ICP,   and correlates with the severity of pruritus. Mild abnormalities of the liver function tests are found, such as elevation of transaminases, alkaline phosphatase, cholesterol and triglycerides; the conjugated bilirubin is elevated (2 to 5 mg/dl) in jaundiced patients. Malabsorption of fat may cause vitamin K deficiency and a prolonged prothrombin time. The symptoms and laboratory abnormalities of ICP typically resolve within 2 to 4 weeks postpartum.
Hormonal, immunologic, genetic, environmental, and alimentary factors have been implicated in the etiology of ICP. Estrogens interfere with bile acid secretion. Progestins inhibit hepatic glucuronyltransferase, and the increased sulfated progesterone metabolites, especially the 3a, 5a -isomers, may saturate the maximal transport capacity of the hepatocyte. An immunologic study showed a Th1 cytokine response and decreased maternal-fetal lymphocyte reaction in ICP. Genetic factors have been suggested by the existence of familial cases, geographic variation and a higher prevalence of ICP in mothers of patients with progressive familial intrahepatic cholestasis or benign recurrent intrahepatic cholestasis. Several studies showed a heterozygous MDR3 missense mutation associated with ICP.
Fetal risks in ICP include stillbirth and preterm delivery. Antepartum testing may be unreliable and a negative antepartum test is not reassuring. Malabsorption of vitamin K increases the risk of intracranial hemorrhage. These complications are related to decreased fetal elimination of toxic bile acids that can cause vasoconstriction of human placental chorionic veins. The risk of serious fetal complications makes intensive fetal surveillance mandatory. Most authors recommend fetal surveillance and cardiotocographic monitoring from the 34th week of gestation. If gestational age is less than 36 weeks, one should monitor liver function tests and bile acids, and consider treatment with ursodeoxycholic acid as well as delivery at 36 to 37 weeks with fetal maturity or continue surveillance if liver function tests improve. If gestational age is more than 36 weeks, amniocentesis and delivery should be considered if the cervix is favorable and fetal lung maturity is satisfactory.