Cyclosporine—Topical and oral calcineurin inhibitors such as cyclosporine have low risk for transmission into breast milk; however, potential effects of exposure through breast milk are unknown. For that reason, manufacturers state that cyclosporine use is contraindicated during lactation.8 If cyclosporine is to be used by a breastfeeding woman, monitoring cyclosporine concentrations in the infant is suggested to ensure that the exposure is less than 5% to 10% of the therapeutic dose.13 The use of cyclosporine has been extensively studied in pregnant transplant patients and is considered relatively safe for use in pregnancy.14 Cyclosporine is lipid soluble and thus is quickly metabolized and spread throughout the body; it can easily cross the placenta.9,13 Blood concentration in the fetus is 30% to 64% that of the maternal circulation. However, cyclosporine is only toxic to the fetus at maternally toxic doses, which can result in low birth weight and increased prenatal and postnatal mortality.13
Isotretinoin, Oral Contraceptive Pills, and Spironolactone
Isotretinoin and hormonal treatments such as oral contraceptive pills and spironolactone (an androgen receptor blocker) commonly are used to treat HS, but all are contraindicated in pregnancy and lactation. Isotretinoin is a well-established teratogen, but adverse effects on nursing babies have not been described. However, the manufacturer of isotretinoin advises against its use in lactation. Oral contraceptive pill use in early pregnancy is associated with increased risk for Down syndrome. Oral contraceptive pill use also is contraindicated in lactation for 2 reasons: decreased milk production and risk for fetal feminization. Antiandrogenic agents such as spironolactone have been shown to be associated with hypospadias and feminization of the male fetus.7
COMMENT
Women with HS usually require ongoing medical treatment during pregnancy and immediately postpartum; thus, it is important that treatments are proven to be safe for use in this specific population. Current management guidelines are not entirely suitable for pregnant and breastfeeding women given that many HS drugs have teratogenic effects and/or can be excreted into breast milk.1 Several treatments have uncertain safety profiles in pregnancy and breastfeeding, which calls for dermatologists to change or create new regimens for their patients. Close management also is necessary to prevent excess inflammation of breast tissue and milk fistula formation, which would hinder normal breastfeeding.
The eTable lists medications used to treat HS. The FDA category is listed next to each drug. However, it should be noted that these FDA letter categories were replaced with the Pregnancy and Lactation Labeling Rule in 2015. The letter ratings were deemed overly simplistic and replaced with narrative-based labeling that provides more detailed adverse effects and clinical considerations.9
Risk Factors of HS—Predisposing risk factors for HS flares that are controllable include obesity and smoking.2 Pregnancy weight gain may cause increased skin maceration at intertriginous sites, which can contribute to worsening HS symptoms.1,5 Adipocytes play a role in HS exacerbation by promoting secretion of TNF-α, leading to increased inflammation.5 Dermatologists can help prevent postpartum HS flares by monitoring weight gain during pregnancy, encouraging smoking cessation, and promoting weight and nutrition goals as set by an obstetrician.1 In addition to medications, management of HS should include emotional support and education on wearing loose-fitting clothing to avoid irritation of the affected areas.3 An emphasis on dermatologist counseling for all patients with HS, even for those with milder disease, can reduce exacerbations during pregnancy.5
CONCLUSION
The selection of dermatologic drugs for the treatment of HS in the setting of pregnancy involves complex decision-making. Dermatologists need more guidelines and proven safety data in human trials, especially regarding use of biologics and immunosuppressants to better treat HS in pregnancy. With more data, they can create more evidence-based treatment regimens to help prevent postpartum exacerbations of HS. Thus, patients can breastfeed their infants comfortably and without any risks of impaired child development. In the meantime, dermatologists can continue to work together with obstetricians and psychiatrists to decrease disease flares through counseling patients on nutrition and weight gain and providing emotional support.