Dermatoses of pregnancy are a group of specific skin diseases that occur during gestation and spontaneously resolve after childbirth. Manifested by itching, urticular, papular, vesicular, bullous, pustular rashes, skin discoloration. They are diagnosed on the basis of immunogram data, RIF, ELISA, the results of histological examination of the biopsy, biochemical blood analysis, seeding of the discharge or scraping. Antihistamines, membrane stabilizers, topical and systemic glucocorticosteroids, and emollients are used for treatment.
L20-L30 Dermatitis and eczema
The category of dermatoses of pregnancy includes four diseases with skin symptoms associated with the gestational period and only rarely manifested after childbirth — atopic dermatitis, pemphigoid, polymorphic dermatosis, obstetric cholestasis. Only 20% of patients with atopic dermatitis had characteristic disorders detected before pregnancy. Pathologies are diagnosed in 1.5-3% of pregnant women, as a rule, who have a hereditary predisposition to allergic reactions and autoimmune diseases. The common distinguishing features that make it possible to combine gestational dermatoses into one group are the benign course, the connection with the period of pregnancy, the presence of itching in the clinical picture.
The etiology of specific skin lesions detected during pregnancy has not been sufficiently studied. Most specialists in the field of obstetrics associate them with physiological hormonal and immune restructuring during gestation. A certain provoking role is played by changes occurring in the skin — stretching of connective tissue fibers, activation of eccrine sweat glands. The immediate causes of dermatoses are considered to be:
- Increased Th2 activity. Changes in immunity in pregnant women are aimed at preventing rejection of the fetus. During gestation, the production of humoral antibodies decreases, the activity of type 1 T-helper cells (Th1) is inhibited. The relative increase in the activity of type 2 T helper cells stimulates the formation of allergen-specific Ig antibodies and the proliferation of eosinophils, which becomes a prerequisite for the formation or exacerbation of atopic dermatitis.
- Damage to connective tissue. The increase in the volume of the abdomen caused by the growth of the pregnant uterus is accompanied by stretching of the skin and damage to connective tissue fibers. Fragments of collagen and elastin can be perceived by cells of the immune system as allergens, which leads to the development of a local autoimmune reaction with the appearance of a skin rash. Such disorders are more often observed in multiple pregnancies, significant weight gain.
- Hereditary predisposition. The basis of most specific dermatoses diagnosed in pregnant women are autoimmune processes. Often, atopic skin diseases are familial in nature and arise as a result of a genetically determined allergic reaction to human leukocyte antigen A31 (HLA-A31), haptogen HLA-B8, placental antigen, which resembles collagen of the basement membrane of the skin (BPAG2, BP180).
Presumably, the mechanism of development of dermatoses in pregnant women is due to a violation of immune reactivity with the development of Th2-type hypersensitivity reactions, activation of mast cells and basophils that secrete inflammatory mediators. In 70-80% of patients, in response to stimulation with placental antigen, fragments of connective tissue fibers, and other autoantigens, the proliferation of type 2 T lymphocytes increases. Th2 cells actively synthesize interleukins 4 and 13, which stimulate the formation of IgE. Under the action of immunoglobulins E, mast cells and basophils are degranulated, macrophages are activated, and the effect of multiple sensitization occurs. Additionally, under the influence of interleukins 5 and 9, eosinophils differentiate and proliferate, which aggravates the atopic response.
In 15-20% of cases, the reaction is caused not by hyperproduction of IgE, but by the influence of pro-inflammatory cytokines, histamine, serotonin, and other factors. Under the action of mediators entering the intercellular space, skin vessels expand, erythema develops, tissues swell, infiltrate with T-helper-2. Depending on the severity of inflammatory changes, itching, papular, vesicular, pustular rash are observed. Of particular importance in the pathogenesis of gestational dermatoses, especially atopic dermatitis, is an imbalance of the autonomic nervous system, manifested by high activity of cholinergic and α-adrenergic receptors against the background of inhibition of β-adrenergic receptors. In patients suffering from obstetric cholestasis, skin irritation is caused by increased excretion and accumulation of bile acids.
The systematization of the forms of the disorder takes into account etiological factors, features of pathophysiological changes, and the clinical picture of the disease. There are the following types of dermatoses of pregnancy, which differ in prevalence, skin symptoms, and the likelihood of a complicated course:
- Atopic dermatitis. Accounts for more than half of cases of skin lesions during gestation. Caused by an enhanced Th2 response. In 80% of cases, it is first diagnosed during pregnancy and subsequently does not manifest itself in any way. It can be represented by eczema, prurigo (pruritus) or itchy folliculitis of pregnant women. Usually these forms of dermatitis are accompanied by discomfort, but do not pose a threat to the course of pregnancy.
- Polymorphic dermatosis of pregnant women. The second most common skin pathology of the gestational period (the incidence is 0.41-0.83%). It is more often detected in the 3rd trimester in patients with multiple pregnancies and in women with a large weight gain. It is associated with an autoimmune response to damage to collagen fibers. It is characterized by itching, polymorphic rash. It does not affect the likelihood of complications during gestation.
- Intrahepatic cholestasis (itching) of pregnant women. Hereditary disease occurring in 0.1-0.8% of patients with genetic defects of the HLA-B8 and HLA-A31 alleles. Itching of pregnant women usually develops in the last trimester of pregnancy. Most likely, dermatological symptoms are the result of the irritating effects of bile acids circulating in the skin. Of all gestational dermatoses, it is the most dangerous in terms of complications.
- Pemphigoid (herpes) of pregnant women. Rare autoimmune pathology, the prevalence of which is 0.002-0.025%. The allergen is a placental antigen that causes a cross-reaction to the collagen of the basal skin membrane. It is manifested by itching, urticaria, vesicular rash. There may be a complicated course of pregnancy, the presence of rashes in a newborn, a relapse of the disease during repeated gestations.
Common signs of dermatoses of pregnancy are itching of varying intensity, rash, discoloration of the skin. Clinical symptoms are determined by the type of dermatosis. Atopic dermatitis is more often detected in primiparous pregnant women in 1-2 trimesters, it can be repeated during subsequent gestations. Itchy eczematous and papular rashes are usually localized on the face, neck, flexor surfaces of the upper and lower extremities, palms and soles, less often spread to the abdomen. With itchy folliculitis, a rare variant of atopic dermatitis, acne occurs on the upper back, chest, arms, shoulders, and abdomen, represented by multiple papules and pustules 2-4 mm in size, located at the base of the hair follicles.
Signs of polymorphic dermatosis appear in primiparous patients in the third trimester, less often after childbirth. Itchy red papules, plaques, pustules initially form on the skin of the abdomen, including over stretch marks, after which they can spread to the chest, shoulders, buttocks, thighs, but almost never affect the mucous membranes, the skin near the navel, on the face, soles, palms. The diameter of individual elements is 1-3 mm, the formation of polycyclic discharge foci is possible.
Urticaria, vesicular, bullous rash in pregnant women with pemphigoid occurs at 4-7 months, initially localized in the umbilical region, then found on the chest, back, limbs. When bubbles and blisters are damaged, erosions and crusts appear. Often the elements of rashes are grouped. With each subsequent gestation, pemphigoid dermatosis begins earlier, accompanied by more pronounced symptoms.
Distinctive features of intrahepatic cholestasis are the primary nature of intense itching and yellowing of the skin, detected in 10% of pregnant women. Itchy sensations usually occur acutely on the palms, soles, gradually spreading to the stomach, back, and other parts of the body. The rash is usually secondary, represented by combs (excoriation), papules. Most often, the clinical signs of the disease are determined in the 3rd trimester.
The probability of a complicated course depends on the type of disease. In most cases, dermatoses of pregnancy recur during the following gestations. The most favorable is atopic dermatitis, which does not provoke the development of obstetric complications and does not affect the fetus. However, in the long-term period, children whose mothers suffered from this dermatosis are more prone to atopic skin diseases. With polymorphic dermatosis, premature birth of a child with a small mass is possible. Due to the transplacental transfer of antibodies, transient papular and bullous rash is detected in 5-10% of children carried out by women with pregnant pemphigoid.
At the same time, dermatoses of pregnancy also increases the risk of fetoplacental insufficiency, fetal hypotrophy, premature birth, postpartum thyroiditis and diffuse toxic goiter in the patient, relapse of the disease when taking oral contraceptives and during menstruation. Itching of pregnant women can be complicated by premature birth, ingestion of meconium into the amniotic fluid, intrauterine distress, stillbirth due to the toxic effect of high concentrations of bile acids. Due to impaired absorption of vitamin K in intrahepatic cholestasis, coagulation processes are more often affected, postpartum bleeding occurs.
Despite the pronounced clinical symptoms, the correct diagnosis of dermatosis of pregnant women is often difficult due to the nonspecific nature of rashes that can be observed in many skin diseases. In favor of the gestational origin of the pathology, its occurrence during pregnancy, the absence of signs of microbial damage, the phasing of the development of rash elements, their spread over the skin. In diagnostic terms , the most informative:
- Determination of the content of antibodies. Atopic dermatitis is characterized by an increase in the content of IgE — a specific marker of allergic reactions. With herpes of pregnant women, the content of IgG4 antibodies in the blood of patients increases, in all patients, during direct immunofluorescence, the deposition of complement 3 along the basement membrane is determined, which is sometimes combined with the deposition of IgG. With the help of ELISA, anti-collagen antibodies characteristic of pemphigoid are detected.
- Examination of a skin biopsy. The results of histological studies are more indicative of pemphigoid and polymorphic dermatoses. In both cases, there is edema of the dermis, perivascular inflammation with infiltration of tissues by lymphocytes, eosinophils, histiocytes. For herpes of pregnant women, subepidermal blisters are pathognomonic, for polymorphic dermatosis — epidermal spongiosis. Pathohistological changes in atopic dermatitis and itching of pregnant women are less specific.
- Biochemical blood analysis. The standard method of diagnosis of obstetric cholestasis is the study of pigment metabolism. Due to the impaired outflow of bile in the blood, a high level of bile acids is determined. In 10-20% of pregnant women with severe dermatosis, the content of bilirubin increases. In 70% of cases, the activity of liver enzymes increases, especially ALT and AST. With other gestational dermatoses, the biochemical parameters of the blood are usually not disturbed.
To exclude bacterial and fungal lesions, it is recommended to sow scraping or discharge rashes on the microflora, luminescent diagnostics. Differential diagnosis is carried out between different types of gestational dermatoses, scabies, drug toxidermia, diffuse neurodermatitis, During’s herpetiform dermatitis, seborrhea, acne, microbial folliculitis, eczema, hepatitis and other liver diseases are excluded. A dermatologist is involved in the examination of the patient, according to indications — an infectious disease specialist, neurologist, gastroenterologist, hepatologist, toxicologist.
The occurrence of gestational skin lesions usually does not become an obstacle to the continuation of pregnancy. Although such dermatoses are difficult to treat due to the constant presence of provoking factors, the correct selection of drugs can significantly reduce clinical symptoms. The treatment regimen is selected taking into account the duration of pregnancy, the intensity of itching, the type and prevalence of rash. For drug therapy , it is usually used:
- Antihistamines and membrane stabilizers. By blocking histamine receptors, they suppress the inflammatory process, reduce itching and rashes. They are prescribed with caution due to possible effects on the fetus, especially in the 1st trimester. Antihistamines of 2-3 generations are preferred.
- Corticosteroids. Due to the pronounced anti-inflammatory effect, all gestational dermatoses are effective, except for itching of pregnant women. They are usually used in the form of topical forms. In severe cases of pemphigoid, polymorphic dermatosis, atopic dermatitis, short courses of systemic glucocorticoids are acceptable.
- Emollients. They are used as auxiliary means to restore the damaged epidermis. Moisturize and soften the skin, restore intercellular lipid structures, accelerate regeneration. Most emollients have no contraindications for use in pregnant women with dermatoses.
- Ursodeoxycholic acid. It is prescribed for the treatment of intrahepatic cholestasis. It affects the calcium-dependent α-protein kinase of hepatocytes, reducing the concentration of toxic fractions of bile acids. Due to competitive interaction, their absorption in the intestine slows down. Increases the outflow of bile.
Pregnancy with gestational dermatoses usually ends on time with natural childbirth. Early delivery is recommended only for severe obstetric cholestasis with a threat to the fetus. Childbirth is stimulated at terms with high survival rates of newborns. Caesarean section is performed only if there are obstetric indications.
Prognosis and prevention
The prognosis for the mother and fetus with dermatoses of pregnancy is usually favorable. Choosing the right tactics for gestation management and monitoring the condition of the child allows you to avoid complications even in complex cases of cholestasis. There are no special measures for the prevention of dermatoses. Patients who have suffered gestational skin lesions during a previous pregnancy need to register at a women’s clinic before 12 weeks, be regularly monitored by an obstetrician-gynecologist and dermatologist, exclude contact with food, industrial, household allergens, and monitor weight gain. Replacement of synthetic underwear with natural ones, careful hygienic care and moisturizing of the skin are recommended.