Pregnancy induces multiple maternal changes, including in the skin, hair, and nails, due to fluctuations in estrogen and progesterone. Most of these changes are benign and reversible.
Spider angiomas are benign, erythematous lesions that blanch with pressure. They occur frequently in pregnancy due to increased estrogen levels that cause increased blood vessel vascularity; they typically resolve postpartum.
Increasing upper lip hair in pregnancy is due to increased circulating androgens (placental and ovarian), causing thickened terminal hair growth. In addition, scalp hair spends more time in the anagen growth phase, causing decreased hair loss. Hair loss occurs postpartum due to a large proportion of hair in the resting telogen phase (ie, telogen effluvium); however, terminal hairs may be permanent.
Polymorphic eruption of pregnancy
Pathologic changes in pregnancy can also occur; therefore, all changing skin lesions should be assessed for possible malignancy.
This patient with prolonged sun exposure has the ugly duckling sign, a variegated (ie, different colors) nevus (eg, black-tan) with irregular borders distinctly different from the other melanocytic nevi (freckles). The ugly duckling sign is concerning for possible melanoma. Increased pigmentation is normal in pregnancy, but color variation is abnormal and requires additional evaluation with biopsy regardless of pregnancy status. Additional indications for biopsy include a change in shape (asymmetry), size, or border regularity.
18121→Variegated nevi, particularly those that change (eg, color, shape), require evaluation and biopsy in pregnant and nonpregnant women due to the possibility of melanoma.