The specific dermatoses of pregnancy: a re-appraisal

A review of pruritus in pregnancy

Pruritus is a common dermatologic complaint during pregnancy. Pruritus is reported by 23-38% of women during pregnancy, and 2% report severe pruritus. In addition to interfering with sleep and reducing overall quality of life during pregnancy, pruritus may be the first, or only, symptom of an underlying disorder that may impact maternal and fetal outcomes. It is therefore critical for all providers caring for pregnant women to be familiar with pregnancy-specific and non-specific conditions associated with pruritus to most effectively manage this unique population. In this review, we discuss clinical classification of pruritus, a practical approach to the differential diagnosis of pruritus in pregnancy, and focus on updates in the clinical features, diagnosis, management, and prognosis of pregnancy-specific causes of pruritus.

Dermatoses of pregnancy: Nomenclature, misnomers, and myths

The most recent reclassification of dermatoses of pregnancy includes polymorphic eruption of pregnancy, atopic eruption of pregnancy, and pemphigoid gestationis; intrahepatic cholestasis of pregnancy, strictly not a dermatosis, was included in specific dermatoses of pregnancy for working purposes. Another dermatosis, pustular psoriasis of pregnancy, could be included for similar reasons. The nomenclature of these pregnancy-specific eruptions has been revised several times, generating potential confusion among practitioners. Clouding the picture further are misnomers that have been used to describe dermatoses of pregnancy. In addition, several cutaneous conditions that are associated with, but not specific to, pregnancy, have been misunderstood, which has resulted in certain myths among patients and physicians. In this contribution, we describe how the nomenclature of each dermatosis of pregnancy has evolved to fit the current classification scheme. We then identify several misnomers that have generated confusion within the scheme. Finally, we debunk several myths that have developed around cutaneous conditions outside of this scheme, in both mother and newborn.

Gestational pemphigoid

Gestational pemphigoid (pemphigoid gestationis, PG) is a rare autoimmune skin disorder occurring characteristically during pregnancy. Autoantibodies against placental BP180 (also known as BPAG2 or collagen XVII) cause damage to the skin basement membrane, resulting in severe itching and blistering rash over the body and the extremities. The diagnosis of PG is confirmed by immunofluorescence analysis of a skin biopsy, while serum levels of pemphigoid antigen BP180 antibody can be used to assess disease activity. PG with mild symptoms can be treated with topical corticosteroids, while oral corticosteroids are the mainstay in treatment of severe PG. PG usually flares up at the time of delivery, and resolves spontaneously shortly after. However, relapses in subsequent pregnancies are common. As PG has been linked to the risk of prematurity and fetal growth restriction, prenatal monitoring jointly by a dermatologist and an obstetrician is recommended. Mothers should also be informed of the potential risk of re-activation of the disease in subsequent pregnancies and during hormonal contraception.

Pregnancy and skin

INTRODUCTION

Skin changes occur in about 90 % pregnant women in one form or the other. The various skin changes maybe either physiological (hormonal), changes in pre-existing skin diseases or development of new pregnancy-specific dermatoses. All of these dermatoses can be attributed to the profound hormonal, vascular, metabolic, and immunological changes occurring during pregnancy.

CLASSIFICATION

Pregnancy-specific dermatoses have now been classified into dermatoses which are definitively associated and dermatoses with uncertain association with pregnancy. Though most of these skin dermatoses are benign and resolve in postpartum period, a few can risk fetal life and require antenatal surveillance. Most of the dermatoses of pregnancy can be treated conservatively but a few require intervention in the form of termination of pregnancy.

CONCLUSION

Careful history taking and examination will help us to identify each condition clinically and appropriate management can be instituted for the well-being of the mother and the fetus.

Pregnancy dermatoses: diagnosis, management, and controversies

Some aspects regarding the etiology and the nosologic classification of various pregnancy dermatoses are highly controversial. While some authors highlight the existence of premises allowing several skin disorders to be re-grouped within broader disease concepts, others underline the absence of clear, undisputed etiopathogenetic data that could support such classifications. This review exhaustively analyzes the various pregnancy dermatoses (pemphigoid gestationis, intrahepatic cholestasis of pregnancy, impetigo herpetiformis, polymorphic eruption of pregnancy, and the papular dermatoses of pregnancy [prurigo of pregnancy, pruritic folliculitis of pregnancy, and the new classification, atopic eruption of pregnancy]) in an attempt to shed light over this confusing and disputed domain, while subsequently offering an algorithmic approach to their diagnosis and management. While for pemphigus gestationis, intrahepatic cholestasis of pregnancy, and impetigo herpetiformis, specific diagnostic tests such as histopathology, immunofluorescence, or laboratory investigations will confirm the diagnosis, the identification of the other types of pregnancy dermatoses is based only on clinical criteria. In this context, the review argues for the inclusion of the whole group represented by the papular dermatoses of pregnancy within the broad spectrum of polymorphic eruption of pregnancy, separating each of these entities by focusing on their onset: early-onset polymorphic eruption of pregnancy (comprising prurigo of pregnancy, pruritic folliculitis of pregnancy, and atopic eruption of pregnancy) and late-onset polymorphic eruption of pregnancy. In light of the same practical approach guiding it, the review provides updated treatment strategies for each of these conditions.

Intrahepatic cholestasis occurring with prurigo of pregnancy

A 23-year-old woman presented to our polyclinic complaining of itching, generalized dermatitis, and jaundice. She was in her 31st gestational week and had developed pruritus and the dermatitis since the first month of pregnancy; her jaundice started about a month before presentation. Her history included similar complaints in a previous pregnancy, which resulted in premature birth of a baby with a permanent brain defect. One of her sisters had had jaundice and itching in her 27th gestational week and delivered a healthy baby; a second sister had experienced itching and dermatitis in her second trimester and delivered a healthy baby. Physical examination of the patient showed that her eyes were jaundiced (Figure 1); skin examination revealed generalized erythematous excoriated papules, symmetrically distributed all over her body (Figure 2 Figure 3). Laboratory analyses revealed the following results: leukocyte count, 14.30/mm(3) (3.8-10.3/mm(3)); erythrocyte sedimentation rate, 25 mm/h (<20 mm/h); aspartate aminotransferase, 44 U/L (5-40 U/L); alanine aminotransferase, 63 U/L (5-40 U/L); lactate dehydrogenase, 1158 U/L (220-450 U/L); total bilirubin, 6.88 mg/dL (<1.10 mg/dL); and direct bilirubin, 3.27 mg/dL (<0.35 mg/dL). Urinalysis results were positive for bilirubin and urobilinogen. Positive serologic findings included rubella immunoglobulin G, 93 AU/mL (<15) and cytomegalovirus, 188 AU/mL (<10); negative findings included herpes simplex virus type 2 and hepatitis. Histopathologic examination of material collected from the left breast via punch biopsy showed parakeratosis, acanthosis, and perivascular lymphocyte infiltration in dermal vessels. Treatment with 2 g/d cholestyramine and a topical corticosteroid was effective in the patient, who was diagnosed with intrahepatic cholestasis of pregnancy and prurigo of pregnancy based on the clinical, histopathologic, and laboratory findings. To the authors' knowledge, this is the first such reported case in the literature.

Less well-defined dermatoses of pregnancy

Over the past several decades, many specific and nonspecific dermatoses of pregnancy have been described. The lack of a well-defined clinical and histological features as well as reproducibility in some of these entities has led to confusing reports in the literature. In this review article, an account of these nonspecific dermatoses of pregnancy will be presented in an attempt to shed light on their nosology and to better categorize them in view of the recent literature findings.

My approach to superficial inflammatory dermatoses

Superficial inflammatory dermatoses are very common and comprise a wide, complex variety of clinical conditions. Accurate histological diagnosis, although it can sometimes be difficult to establish, is essential for clinical management. Knowledge of the microanatomy of the skin is important to recognise the variable histological patterns of inflammatory skin diseases. This article reviews the non-vesiculobullous/pustular inflammatory superficial dermatoses based on the compartmental microanatomy of the skin.

[Pruritus in pregnancy. A frequent diagnostic and therapeutic challenge]

Pruritus is the leading dermatological symptom during pregnancy. Besides preexisting or acquired dermatoses, there are a number of pregnancy-specific dermatological diseases such as PEP (polymorphic eruption of pregnancy, previously named PUPPP), pemphigoid (herpes) gestationis, and pruritus gravidarum that are accompanied by severe itching and scratching. Because of potential effects on the fetus, the treatment of pruritus in pregnancy requires prudent consideration. The use of topical and systemic treatments depends on the underlying aetiology of pruritus and the stage and status of the skin. In general, emollients, topical anti-pruritics and topical corticosteroids appear to be the safest options for localised forms of pruritus in pregnancy whereas systemic treatments and/or UV phototherapy are adequate for generalized pruritus. Systemic corticosteroids and a restricted number of antihistamines may be administered in severe cases. This paper highlights the major aetiologies of pruritus during pregnancy and points out the cornerstones of antipruritic therapy in recognition of our own clinical experiences and the current literature.

Prurigo: diagnosis and management

Prurigo is a condition of nodular cutaneous lesions that itch (pruire) intensely. Although the acute form can be caused by insect stings, most of the subacute and chronic forms appear to be idiopathic. Toxic agents deposited in the skin by exogenous factors such as parasites, bacteria, or topically or orally administered drugs can induce itch. In susceptible individuals, physical mechanisms such as UV light can induce changes in epidermal innervation that result both in itch generally and in prurigo lesions. Prurigo is sometimes associated with atopy, pregnancy, internal diseases, malabsorption, or malignancy. Some forms of prurigo may be secondary to scratching. Emotional factors can also influence the perception of itch and induce prurigo by provoking scratching. These are the various specialized forms of prurigo, and there are certain others, such as prurigo pigmentosa, that have some ethnic preference. Topical treatments by corticosteroids, coal tar, bath photochemotherapy, UVB, cryotherapy, or capsaicin, as well as systemic regimens involving use of psoralen + UVA (PUVA), erythromycin, arotinoid acid, cyclosporine, chloroquine, dapsone, minocycline, naltrexone, azathioprine or thalidomide are used for the treatment of this condition. Psychotherapeutic agents to treat problems of mood that deteriorate prurigo are also prescribed. Combined sequential treatments for generalized, therapy-resistant cases need to be tailored to the exacerbations that occur and to provide maintenance treatment in order to enable the patient to withstand the intolerable itch.