Due to hormonal changes during pregnancy, the skin undergoes several physiological changes. Inflammatory and autoimmune conditions can also rarely develop during pregnancy.
Skin around the nipple and genital becomes dark and a dark line develops in the middle of the abdomen (called Linea Nigra).
There may be purplish to pink streaks along the abdomen as the baby grows in the womb because of the stretching of the skin. These are called Striae.
Some women also develop pigmentation on the face (melisma)
Pruritic and urticarial papules and plaques of pregnancy (PUPPP)
Also known as Polymorphic eruption of pregnancy. It is a relatively common skin disorder that occurs in women of childbearing age. It usually presents in women during their first pregnancy. It is characterised by an itchy rash that commonly begins on the abdomen, particularly within stretch marks (striae). It most usually develops during late pregnancy (third trimester) but can also start immediately after the baby is born. It commonly spreads on the trunk, lower abdomen, under the breasts and limbs. The face, scalp and mucous membranes (mouth and genital area) are hardly ever affected. Small blisters are sometimes present. The baby is unaffected in this condition.
Pemphigoid Gestationis
Pemphigoid gestationis is a rare skin blistering disorder that occurs in women. It usually presents in the 2nd trimester with an itchy rash that develops into blisters. It may recur in subsequent pregnancies. Pemphigoid gestationis is an auto-immune blistering disease. This means that the mother’s immune system starts reacting against her own skin causing the skin to split and form blisters. Itching is common and the rash often starts around the umbilicus. It starts with urticarial wheals (like hives from nettles) and large raised red patches (plaques) commonly occurring on the trunk, back, buttocks and limbs. Large tense blisters then occur on the red patches within 1-2 weeks, and may also occur on palms and soles. The blisters contain clear fluid though occasionally this can be blood-stained. The blisters usually heal without scarring.
Occasionally the baby will develop a blistering rash following delivery due to transfer of the mother’s antibodies across the placenta. The rash can last up to 6 weeks until the mother’s antibodies are cleared from the baby’s system. The baby is at increased risk of premature delivery and may be relatively small as compared to a normal full term baby.