During pregnancy, many pregnant women will have coexisting or new or old dermatologic disorders. If the initial obstetrician is familiar with common dermatologic treatment options, they can effectively treat most pregnant women with skin conditions. Treatment by a specialized dermatologist is important, but an obstetrician’s knowledge of common skin conditions is also essential. In order to provide obstetricians with a better understanding of the common treatments for the various skin disorders of pregnancy, Dr. TYLER of the Department of Dermatology at The Ohio State University summarized the treatment of skin disorders of pregnancy and published the results of his research in the journal Clinical Obstetrics and Gynecology. Classification of Drugs in Pregnancy All obstetricians should be familiar with the Food and Drug Administration (FDA) classification of pregnancy and lactation. The classification was developed after birth defects associated with the use of caprylestrol and thalidomide occurred in the 20th century. Each drug is categorized into categories 1-5 and listed in Table 1. Although this is the most commonly used classification system, many of the credit ratings are based on limited animal experimental data and case reports, and updates to the ratings are often slow. Therefore, cross-referencing with other drug safety resources may be the best way to confirm up-to-date information on drug safety in pregnancy. MEDICATIONS FOR SKIN DISEASES IN PREGNANCY For skin disorders in pregnancy, topical medications are generally the first choice because they have the advantage of having the lowest absorption limits and the least impact on the fetus.Dr. TYLER recommends appropriate treatments for pregnant women with skin disorders based on the current FDA drug classifications. Although sebaceous gland activity increases in late pregnancy, not all patients experience predictable worsening of acne, which is generally considered unaffected during pregnancy. Although safe medications are limited, many topical medications remain the best option for pregnant women with acne. Many topical antibiotics can be safely used during pregnancy. Benzoyl peroxide is currently classified as Category C, but it is a safe and worthwhile medication to consider for acne during pregnancy. Azelaic acid cream (azeleic) belongs to category B and is also a good choice at <4% of the dose absorbed systemically. Although salicylic acid is an anti-inflammatory agent, it belongs to category C with systemic absorption of about 9-25%. Because of the potential for early closure of the ductus arteriosus and amniotic fluid hypotension following anti-inflammatory drug therapy in late pregnancy, pregnant women should be careful not to apply the drug extensively for long periods of time or in a closed dressing, which can increase systemic absorption. Most topical antimicrobials can be safely used in obstetric patients. Topical metronidazole, erythromycin, and clindamycin for the treatment of acne and rosacea all fall into category B and can be safely used during pregnancy. Two other antimicrobial agents used for skin disorders, topical aminoglutethimide and topical sulfasalazine sodium, both belong to category C and can also be used in pregnant patients. Aminosulfone is an oral agent for the treatment of herpetic dermatitis and leprosy during pregnancy, and no adverse effects of this drug on the fetus have been reported in the literature. There is a theoretical risk of neonatal hyperbilirubinemia with use near delivery, so clinicians should be cautious about discontinuing the drug during the last month of pregnancy. Topical retinoids, including retinoids and adapalene, are classified as Category C. Topical retinoids and topical adapalene are the least absorbed, but some studies have shown teratogenic effects of these drugs in early pregnancy. No such risk has been seen in studies in mid- to late pregnancy, so these medications may be considered for use in mid- to late pregnancy, after physician consultation. Safe drugs include oral cephalosporins, penicillins, and azithromycin, all of which are class B. Erythromycin is also class B, but Swedish studies have reported a risk of cardiovascular malformations in early pregnancy, and prolonged use of the ethylsuccinate formulation has rarely caused hepatotoxicity in pregnant women, so the other B antibiotics are a better choice for the treatment of acne of pregnancy. Tetracyclines belong to class D and are stored in developing teeth and bone in early pregnancy, causing yellowing of the teeth and enamel hypoplasia, and these drugs have also been associated with acute fatty liver of pregnancy, so this class of drugs is generally not used in pregnancy. In addition, oral retinoids such as isotretinoin and Avitamin A, which are well-known class X teratogens, should not be used in pregnancy. Psoriasis Psoriasis is a chronic inflammatory skin disease that affects 2-3% of the population but is not uncommon in obstetric patients. 50% of pregnant patients with psoriasis will improve during pregnancy, but 20% will worsen. For most skin conditions, topical medications are the first line of treatment, but patients with moderate to severe psoriasis may require systemic medications. Tauscher et al. published a detailed review outlining stepwise treatment options for pregnant women with psoriasis. Topical glucocorticoids are the recommended first-line treatment, followed by topical calcipotriol, topical anthralin, and topical tacrolimus. All 4 drugs fall under FDA pregnancy category C. Application of glucocorticoids by obstetricians is readily available for a variety of medical conditions during pregnancy, and most glucocorticoid use during pregnancy is appropriate. Absorption of topical steroids depends on 4 major factors: site of application, amount applied, medium of treatment, and occlusion. To avoid excessive absorption, certain studies have demonstrated that pregnant women should not use large amounts of occlusive dressings or large areas to avoid the risk of low birth weight in the newborn. Avoiding overabsorption of topical glucocorticoids should follow the principles of topical calcipotriol use during pregnancy. Some animal studies have shown fetal skeletal abnormalities, but one does not get similar results in human studies. If topical corticosteroids and topical calcipotriol fail, anthracene and tacrolimus are alternative topical treatments, but both are limited to small areas. For moderate to severe psoriasis, topical treatments are insufficient and the patient would do well to consult a specialized dermatologist. Oral retinoids, such as isotretinoin and methotrexate, are classified as Category X and are contraindicated in pregnant women and women who may become pregnant. Broad-spectrum medium-wave ultraviolet therapy is the safest systemic treatment, but overheating should be avoided due to the risk of neural tube defects with heat therapy in early pregnancy. Because the risk of neural tube defects may increase during treatment, patients may consider monitoring folate levels during phototherapy. Biologics, such as infliximab, etanercept, and adalimumab, are pregnancy category B drugs, but there are limited data related to these drugs. Finally, cyclosporine, which is a class C drug, is one of the options for the treatment of moderate to severe plaque psoriasis in pregnancy. Atopic Dermatitis As with psoriasis, topical corticosteroids are the first-line therapeutic agents for atopic dermatitis in pregnancy. Pimecrolimus, another commonly used medication for the treatment of atopic dermatitis, is a class C medication and no problems have been reported with small-scale applications. If topical glucocorticoids do not control symptoms, pimecrolimus would be the next logical step in treatment. The drug can be used in pregnant women with severe or persistent atopic dermatitis, while a dermatologist should assist in the consultation. Short-term oral doses of steroids appear to be safe for use during pregnancy, as does cyclosporine. Mycophenolate mofetil belongs to class D and is an immunosuppressant used in the treatment of moderate-to-severe atopic dermatitis, but should not be used during pregnancy because of reported cases of teratogenicity due to congenital anomalies including cleft lip and palate, renal, cardiac, esophageal, and distal limb abnormalities. The use of oral antihistamines for the treatment of pruritus during pregnancy is safe as most of the drugs belong to class B. The use of oral antihistamines during pregnancy is safe as most of the drugs belong to class B. Antihistamines should be avoided in breastfeeding women because of the sedative effect of this class of drugs on the newborn. Connective Tissue Diseases Hydroxychloroquine used in patients with SLE or discoid lupus erythematosus complicated by pregnancy belongs to class C. It is not recommended to stop using this medication because it can cause a relapse of the disease. Discontinuing this drug can bring the disease back, and it is not associated with a specific congenital abnormality, so most experts recommend that patients already taking the drug continue treatment. Consultation with a high-risk obstetrician and / dermatologist will help in these cases. For cutaneous lupus, topical steroids and short-term oral steroids during pregnancy are sufficient treatment. Bacterial, Fungal, and Parasitic Infections Most obstetricians are familiar with which antibiotics are safe to use in obstetric patients with bacterial skin infections; as discussed earlier cephalosporins, penicillins, and azithromycin all fall into category B and can be safely used during pregnancy. Most topical antimicrobials used for dermatologic conditions and infections, including erythromycin, clindamycin, metronidazole, mupirocin, neomycin, and polymyxin B, belong to category B. For fungal infections, topical drug therapy is considered a safer alternative to oral medications. Oxiconazole and clotrimazole are the topical medications of choice, and all belong to class B in pregnancy. Other safe options include class B topical antifungals, naftifine, butenafine, terbinafine, ciprofloxacin, and mycobacteria, none of which have been reported to have adverse effects in pregnancy. Oral antifungals have a greater risk compared to topical medications. Terbinafine is the only class B oral antifungal agent that is a systemic treatment modality for pregnant women with dermatophytosis; however, it is not recommended for the treatment of onychomycosis in pregnant women. Imidazoles and ashwagandha belong to pregnancy category C. Ketoconazole inhibits androgen synthesis and reduces progesterone production; it is not recommended during pregnancy. The newer imidazole antifungals (including fluconazole and itraconazole) belong to category C. Large cohort studies have shown that they are not teratogenic. Some studies have shown a risk of congenital malformations with long-term high doses of fluconazole, but several studies have confirmed the safety of a single oral dose, and this typical dose is commonly used by obstetricians and gynecologists for vaginal candidiasis. Finally, animal studies have shown an increased risk of central nervous system and skeletal abnormalities with ashwagandha, and other studies have shown an increased risk in conjoined infants, so it is not recommended during pregnancy. For parasitic infections (e.g., scabies and lice infections during pregnancy), topical permethrin belongs to category B. It is the first-line drug for the treatment of these conditions, and is widely used in pregnancy because of its low systemic absorption, with few reports of adverse effects. Dermatologic Surgery in Pregnancy To avoid the risk of preterm labor in late pregnancy and miscarriage in early pregnancy, non-emergency surgery is mostly recommended in mid-pregnancy and postpartum. Surgery during pregnancy should avoid the supine position. Alcohol and chlorhexidine preparations are more effective than povidone-iodine and hexachlorophenol due to reports of fetal hypothyroidism and fetal central nervous system toxicity after absorption through maternal mucosa. Most local anesthetics are used for most dermatologic procedures. Lidocaine and proparacaine both belong to category B and are preferred for use during pregnancy. Many studies have shown no adverse effects of these drugs on the fetus. Acetaminophen or small doses of class C opioids provide analgesia for most dermatologic procedures. Destruction of localized lesions using laser ablation, cryotherapy, or trichloroacetic acid can usually be performed safely during pregnancy. Interferon, Pudafylline, and 5-fluorouracil creams are not recommended for use during pregnancy due to concerns about fetal and maternal safety.