Highlights from

AAD 2021

American Academy of Dermatology Virtual Meeting Experience 2021

Virtual 23-25 April 2021

Clearing the confusion around dermatoses in pregnancy

Summary: The current classification system for dermatoses in pregnancy is based on a study from 2006. Confusion may occur due to overlap between different categories. Here, a simplified classification system is proposed that recommends determining the presence of primary skin lesions and the stage of pregnancy.

Dr Marcia Driscoll (University of Maryland, US) explained that there is confusion about dermatoses of pregnancy (DPS).1 The current classification of DPS is based on the largest study of DPS to date that retrospectively studied 505 pregnant patients.2 Dr Driscoll and colleagues proposed classifying the dermatoses of pregnancy as polymorphic eruption of pregnancy (PEP), pemphigoid gestationis (PG), atopic eruption of pregnancy (AEP), and intrahepatic cholestasis of pregnancy (ICP).

PEP demonstrates with pruritic oedematous and erythematous papules and plaques typically starting within striae distensae and/or on the abdomen with umbilical sparing. The diagnosis can be made clinically. When in doubt, a biopsy for pathology can be performed, combined with direct immunofluorescence (DIF); lab values are typically normal. Treatment is done with topical steroids and antihistamines; diphenhydramine and chlorpheniramine are considered safe in pregnancy. There is no danger to mother or infant.

PG is rare in pregnancy and has a genetic component. In pregnant women, it is characterised by abnormal expression of MHC class II antigens within the placenta. A local immune response is produced with antibody production in the placenta. In most cases, a later onset in pregnancy is observed, and even up to 25% of cases occur immediately postpartum. The clinical presentation starts on the abdomen and involves the umbilicus. The diagnosis is done by histology and DIF and patients can be treated with systematic steroids. Recognising PG is important because of the increased risk for prematurity and small-for-gestational-age infants, especially in more severe disease.

AEP includes the previous categories EP, PP, and PEP, due to overlapping. It occurs early, before the third trimester. The diagnosis is clinical and based on a history of atopy. If present, pustules should be cultured. Treatment consists of topical corticosteroids and antihistamines.

ICP has a strong genetic and environmental component, as well as some hormonal influences as a result of increased steroid levels. ICP normally presents in the third trimester with an onset of pruritus on hands and feet, becoming more generalised in a later stage. The easiest method of diagnosis is increased fasting serum bile acids. Because of the increased risk for prematurity (19-60%), usually, early induction of labour is considered. Recurrence in subsequent pregnancies may exist.

Taken together, Dr Driscoll recommended a classification for pruritus in pregnancy in which categorisation should take place firstly based on primary skin lesions and secondly on pregnancy trimester for the characterisation of dermatoses.

  1. Driscoll M. Specific dermatoses of pregnancy. Session F004: The Pregnant Pause: How to evaluate and treat your pregnant patients. AAD VMX 2021, 23-25 April 2021.
  2. Ambros-Rudolph C, Müllegger R R et al. The specific dermatoses of pregnancy revisited and reclassified: results of a retrospective two-center study on 505 pregnant patients. J Am Acad Dermatol. 2006;54,395-404 [full text]

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Article image: doble-d

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