Journal of the American Academy of Dermatology
Volume 56, Issue 4 , Pages 708-709, April 2007

Pruritic dermatoses of pregnancy: To lump or to split?

  • Lisa M. Cohen, MD

      Affiliations

    • Departments of Dermatology at Tufts University School of Medicine, Boston
    • Cohen Dermatopathology, Newton, Mass
    • ,
  • George Kroumpouzos, MD, PhD

      Affiliations

    • Rhode Island Hospital, Brown Medical School, Providence, RI
    • Corresponding Author InformationCorrespondence to: George Kroumpouzos, MD, PhD, 9 Hawthorne Place, Ste 6D, Boston, MA 02114.

Article Outline

 

To the Editor: We read with interest the study by Ambros-Rudolph et al1 in the March 2006 issue of the Journal that proposes a reclassification of specific dermatoses of pregnancy. We have some concerns that it represents a classification of pruritic rather than specific dermatoses. For example, eczema and intrahepatic cholestasis of pregnancy (ICP) were not included in the specific dermatoses of pregnancy in previous studies by the authors.2

First, the article does not provide any significant new etiopathogenetic data but only evidence of clinical overlap. Also, this retrospective analysis from medical records may contain methodological biases, because numerous physicians could have been involved in the diagnoses over a 10-year period, and confirming diagnostic accuracy retrospectively seems impossible. Furthermore, the clinical overlap that the authors claim is based to some extent on the personal or family history of atopy, the report of which is often vague in medical records and/or may be based only on patients' reports.

Second, it is difficult to estimate the prevalence of certain dermatoses retrospectively. Pruritic folliculitis of pregnancy (PFP), for example, requires a familiarity with the entity and high index of suspicion to prompt a skin biopsy.3 The authors found only 1 case of PFP in the present study but 14 in their previous study.2 Perhaps some PFP cases were missed because a biopsy was not taken and/or the patients were misdiagnosed as having eczema. The authors report “a few more” PFP cases after the original description, while our literature search shows 26 cases. Additionally, it seems arbitrary that the authors combine the one case of PFP in this study with the broad category of “atopic eruption of pregnancy” (AEP) solely on the basis of a history of childhood eczema and family history of atopy. Of note, none of the 32 PFP cases that have been reported have been associated with atopy.2, 4

Third, the authors have previously speculated that prurigo of pregnancy (PP) could be the result of pruritus gravidarum in persons with an atopic diathesis, based mainly on serum IgE elevation in 4 out of 12 PP patients2 (with no control group). Nevertheless, elevated serum IgE is a nonspecific feature of atopic dermatitis, and low IgE titres have a low diagnostic value; the median IgE value in this study (156 kU/L) was close to normal range (<100 kU/L). Of note, IgE was elevated in only 13 out of 72 eczema patients in the previous study of the authors.2

Furthermore, a significant number of PP patients never had eczema or a well-documented atopic predisposition.2, 3 As the authors indicate, 4 out of 49 PP patients in this study showed only minor criteria of atopy, but they still grouped these cases under “AEP.” It would be useful to know how many out of the 49 PP patients had IgE elevation, even though elevated serum IgE is not proof of an atopic diathesis. Maternal serum IgE during pregnancy can be affected by ethnic, genetic, and psychosocial factors.5 In order to provide more conclusive data about the role of IgE, it would be useful to measure serum IgE in the PEP and ICP groups as well as in a control group of pregnant women without any skin disease.

Finally, the unexpectedly high prevalence of new eczema in pregnancy (79%) in this study, as opposed to exacerbation of preexisting eczema (21%), is higher than that of the previous study2 (52/72; 72%). In our opinion, this high prevalence is caused by the authors' use of minor criteria of atopy in the diagnosis of new eczema, the accuracy of which is often difficult to confirm retrospectively. It is also caused by the fact that the authors combine a number of pruritic dermatoses (PP, PFP, and eczema) under the label “AEP.” It is possible that pruritus can cause secondary eczematous-looking lesions in PP and PFP patients, but the sequence of events could not have been revealed retrospectively.

In sum, the authors make an attempt to lump several entities together and provide a useful algorithm for the differential diagnosis of pruritic skin diseases in pregnancy. It may be more appropriate to say that they provide a simplified classification of pruritic dermatoses of pregnancy, with emphasis on atopy, rather than a reclassification of specific dermatoses of pregnancy based on new etiopathogenetic data.

Back to Article Outline

References 

  1. Ambros-Rudolph CM, Mülleger RR, Vaughan-Jones SA, Kerl H, Black MM. 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
  2. Vaughan Jones SA, Hern S, Nelson-Piercy C, Seed PT, Black MM. A prospective study of 200 women with dermatoses of pregnancy correlating the clinical findings with hormonal and immunopathological profiles. Br J Dermatol. 1999;141:71–81
  3. Kroumpouzos G, Cohen LM. Specific dermatoses of pregnancy: an evidence-based systematic review. Am J Obstet Gynecol. 2003;188:1083–1092
  4. Kroumpouzos G, Cohen LM. Pruritic folliculitis of pregnancy. J Am Acad Dermatol. 2000;43:132–134
  5. Lin YC, Wen HJ, Lee YL, Guo YL. Are maternal psychosocial factors associated with cord immunoglobulin E in addition to family atopic history and mother immunoglobulin E?. Clin Exp Allergy. 2004;34:548–554

PII: S0190-9622(06)04085-0

doi:10.1016/j.jaad.2006.08.075

Journal of the American Academy of Dermatology
Volume 56, Issue 4 , Pages 708-709, April 2007

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