Williams Manual of Pregnancy Complications, 23 ed.

CHAPTER 82. Dermatological Disorders

Most skin diseases are encountered with similar frequency in pregnant and nonpregnant women. There are, however, a number of physiological skin changes induced by the hormonal influences of pregnancy. In addition, there are a number of pregnancy-specific dermatoses that are commonly symptomatic and in some cases have been associated with adverse pregnancy outcome.

PHYSIOLOGICAL SKIN CHANGES IN PREGNANCY

Hormonal changes in pregnancy may have remarkable influence on the skin. Fetoplacental hormone production, stimulation, and clearance can increase plasma availability of estrogens, progesterone, and androgens. Likewise, there are profound changes in the availability or concentrations of adrenal steroids, including cortisol, aldosterone, and deoxycorticosterone. Presumably due to enlargement of the intermediate lobe of the pituitary gland during pregnancy, plasma levels of melanocyte-stimulating hormone become elevated by 8 weeks’ gestation.

Hyperpigmentation

Some degree of skin darkening is observed in 90 percent of all pregnant women. This hyperpigmentation is evident early in pregnancy and is more pronounced around naturally pigmented areas such as the areolae, perineum, and umbilicus. Areas prone to friction, including the axillae and inner thighs may also become darkened. When the linea alba becomes darkened, it is renamed the linea nigra. Pigmentation of the face is called chloasma or melasmaand occurs in 50 percent of pregnant women. Melasma is aggravated by sunlight or other ultraviolet light exposure and can be decreased with limited exposure to sunlight and use of sunscreen. Treatment with 2- to 5-percent hydroxycortisone or 0.1-percent topical tretinoin may improve the condition.

Nevi

All persons have some form of benign or melanocytic nevi. Traditionally, it has been taught that nevi enlarge and darken during pregnancy, although this may occur less than 10 percent of the time. Importantly, pregnancy does not appear to increase the risk of transformation into malignant melanoma. Pregnancy may, however, delay identification of a malignant melanoma once formed. Interestingly, engrafted endothelial-type fetal cells, have been found in both, nevi and malignant melanomas in pregnant women.

Changes in Hair Growth

During pregnancy, there is an increase in the proportion of anagen (growing hair) phase to telogen (resting hair) phase. Estrogens prolong the anagen phase, and androgens enlarge hair follicles in androgen-dependent areas such as the beard. As these effects are lost postpartum, shedding of the hair becomes prominent (telogen effluvium).

Mild hirsutism is common in pregnancy, especially in women who are genetically predisposed. More severe degrees of hirsutism are uncommon and, if masculinization is present, should prompt evaluation for another androgen source. This condition is occasionally caused by an adrenal tumor or pregnancy-related luteoma.

Vascular Changes

Augmented cutaneous blood flow and estrogen-induced changes in the small vessels can result in vascular changes that regress postpartum. These include spider angiomas and palmar erythema. Capillary hemangiomas, especially of the head and neck, are seen in approximately 30 percent of women during pregnancy. Pregnancy gingivitis or epulis of pregnancy is caused by growth of the gum capillaries. It may become more severe as the pregnancy progresses but can be controlled by proper dental hygiene and avoidance of trauma. Granuloma gravidarum describes typical pyogenic granulomas, which are found in the oral cavity arising from the gingival papillae.

DERMATOSES OF PREGNANCY

A number of dermatological conditions have been identified as being associated with pregnancy. Three are considered unique to pregnancy: cholestasis, pruritic urticarial papules and plaques of pregnancy (PUPPP), and herpes gestationis (Table 82-1). Approximately 1.6 percent of women have significant pruritus during pregnancy.

TABLE 82-1. Dermatoses Unique to Pregnancy

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PREEXISTING SKIN DISEASE

A number of dermatological disorders may complicate pregnancy. As with other chronic disorders, many of these diseases have no predictable course during pregnancy.

Acne

For the pregnant woman with severe acne, topically applied benzoyl peroxide appears to be safe. Retinoic acid derivatives such as isotretinoin (Accutane), oral tretinoin, and etretinate are all contraindicated during pregnancy because of associated teratogenic effects, including craniofacial, cardiac, and central nervous system malformations. Topical tretinoin is absorbed poorly and thought to pose no significant teratogenic risk (Briggs GG, Freeman RK, Yaffe SJ (eds): Drugs in Pregnancy and Lactation. Philadelphia, PA, Lippincott Williams & Wilkins, 2005, p 1613; Leachman SA, Reed BR: The use of dermatologic drugs in pregnancy and lactation. Dermatol Clin 24:167, 2006).

Hidradenitis Suppurativa

This is a chronic, progressive inflammatory and suppurative disorder of skin and supporting structures characterized by apocrine gland plugging, and leading to anhidrosis and bacterial infection. It typically involves the axillae, groin, perineum, perirectal area, and the area under the breasts. Treatment of acute infections is usually with systemic antimicrobial agents or clindamycin ointment. Definitive treatment is wide surgical excision, but this should be postponed until after pregnancy.

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FIGURE 82-1 Pruritic urticarial papules and plaques of pregnancy (PUPPP). (Reproduced, with permission, from Cunningham FG, Leveno KJ, Bloom SL, et al (eds). Williams Obstetrics. 23rd ed. New York, NY: McGraw-Hill; 2010.)

OTHER CONDITIONS

The majority of women report improvement of psoriasis with pregnancy. Almost 90 percent, however, report a postpartum flare. If pemphigus appears during pregnancy for the first time, it may be confused with herpes gestationis. Even with corticosteroid therapy, mortality related to pemphigus is 10 percent due to sepsis caused by infection of denuded skin. Lesions of neurofibromatosis may increase in size and number as a result of pregnancy. Leprosylikely worsens during pregnancy.

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FIGURE 82-2 Herpes gestationis. (Courtesy of Dr. Amit Pandya.) (Reproduced, with permission, from Cunningham FG, Leveno KJ, Bloom SL, et al (eds). Williams Obstetrics. 23rd ed. New York, NY: McGraw-Hill; 2010.)


For further reading in Williams Obstetrics, 23rd ed.,

see Chapter 56, “Dermatological Disorders.”