1. pruritic urticarial papules and plaques of pregnancy (PUPPP for short) is a common pruritic skin condition during pregnancy, with an incidence of about 1:200. once it occurs, it lasts throughout pregnancy and is typically characterized by red, pruritic masses distributed along the tension line in the abdomen and then spreading to other parts of the body such as the thighs, hands and feet. It usually occurs in mid to late pregnancy. It resolves spontaneously within a few weeks after delivery and does not affect maternal or infant health. It occurs most often in the first child, and is less likely to occur after the second child. It is also more likely to occur in expectant mothers with multiple births or rapid weight gain during pregnancy. The exact cause is unknown and is associated with hormonal changes, mechanical tension line stretching and changes in the immune system. If left untreated, mothers-to-be often experience severe sleep disturbances due to itching. Apart from affecting the life of the mother-to-be, this type of skin disorder has no impact on the health of the fetus or the mother herself, as it is mostly benign. Usually the greatest pain for the mother is the itching, which severely disrupts sleep and rest. Treatment may be oral antihistamine or topical steroid creams applied to relieve the symptoms, which mostly belong to grade B on the grading scale. 2, pregnancy itch rash Its may be related to hormonal changes during pregnancy, mosquito bites or dry skin and foreign irritants and other factors, there is no significant impact on the fetus and the mother. It usually occurs in the middle and late stages of pregnancy (between about 4 and 9 months of pregnancy). It occurs on the proximal extremities of the limbs, including the thighs or arms. They appear as red or pale pink papules, which are itchy and gradually heal after delivery and may leave temporary pigmentation marks. To avoid being bitten by mosquitoes, pregnant women try not to use mosquito coils and other chemicals to repel mosquitoes, the best way is to use mosquito nets. Treatment is mainly based on external steroid creams. 3, pregnancy pruritic folliculitis pregnant women due to high metabolism, hot weather, sweating more, if not pay attention to cleanliness and hygiene, is likely to trigger pregnancy pruritic folliculitis. This disease occurs mostly in the second and third trimesters of pregnancy, with a generalized red papule along the hair follicles in the abdomen, which may resolve on its own during or after delivery. This disease is mainly treated symptomatically. For treatment, pruritic folliculitis can be treated with topical glycolic lotion (commonly known as prickly heat water), in addition to some antibacterial ointments such as chrysin and erythromycin. During the disease, avoid eating too greasy and sugary food, especially should pay attention to the cleanliness of the skin hygiene. 4, pregnancy pruritus, also known as bile depression pruritus occurs mostly in late pregnancy. The incidence is about 0.02% to 2.4%. In severe cases, it may lead to stillbirth and premature delivery, and the mother-to-be must be especially careful. The onset of the disease is due to the increase in estrogen during pregnancy, causing bile accumulation in the liver, and the accumulation of bile acid salts to stimulate the skin nerve endings, and not caused by eating any inappropriate food or external stimulation. It is often manifested only as severe generalized pruritus and jaundice, which can be followed by epidermal peeling, and some patients develop jaundice within a few days to a few weeks after the onset of pruritus, with a jaundice incidence of about 20%. The palms of the hands and feet are common sites of pruritus, which may persist until delivery and recur with subsequent pregnancies. The majority of cases disappear 2 days after delivery, with a few cases disappearing in about 1 week, and it is rare for it to persist for more than 2 weeks. It is rare in the first pregnancy, but the incidence is as high as 47% in the second pregnancy. Topical lubricants and antipruritic agents are effective in mild ICP; deferoxamine may be effective in 50% of mild ICP; antihistamines are rarely effective; 450 to 1,200 mg of andrographolide daily is very effective in controlling pruritus and serologic abnormalities in ICP; when used in combination with S-adenosylmethionine, the efficacy is significantly increased. 5. Gestational aspergillosis This is an autoimmune disease. In about half of the cases, the first manifestation is a sudden onset of severe itching and abdominal urticaria-like rash, which may have target-like damage and rapidly progresses to a generalized maculopapular rash, often without involvement of the face, scalp, or oral mucosa; it usually resolves in the second trimester and worsens during delivery, with the rash resolving in the weeks or months after delivery in most cases. Prematurity often occurs in infants, and in less than 5% of cases the infant may present with urticarial lesions and macules, which are often limited and may spontaneously resolve without treatment. The main goal of treatment is to reduce itching and stop the formation of blisters. Before the formation of blisters, local glucocorticoids and oral antihistamines can be used, and in severe cases, glucocorticoids need to be used systematically. 6, herpes-like pustulosis is characterized by occurring mainly in pregnant women in the last three months of pregnancy, occasionally in men. The pustules are clustered or arranged in a circular pattern and form yellow crusts after drying, with flushed, infiltrated but non-ulcerated skin under the crusts. Patients often have hypoparathyroidism and hypokalemia in combination. Recently, there has been a tendency to classify the disease as pustular psoriasis complicated by pregnancy.