Psoriasis is a well-known skin disease caused by an overactive immune system that causes increased inflammation in one’s own skin. Depending on the type of psoriasis, this can result in thick red plaques all over the body that are sometimes covered with a silvery/white layer of flaky scale. This condition can be physically painful and troublesome, as it can be associated with bleeding, itching, and burning symptoms. Recently, researchers have also studied a link between psoriasis and heart disease, diabetes, certain types of cancer, depression, and other systemic diseases. However, many patients would agree that the psychosocial burdens of the disease are the greatest. It can be a very visible skin condition and is often, but wrongfully, associated with a contagious disease in social settings.
Interestingly, several studies report that psoriasis greatly improves in around half of all affected women during their pregnancy. There is some evidence that this is related to the higher concentration of estrogen in the body during this time. Despite this observed trend, certain individuals actually experience a worsening of their condition during pregnancy and desire to pursue safe and effective therapy to control their disease. Fortunately, mild to moderate forms of the disease do not seem to have any adverse outcomes on the pregnancy or the fetus. However, the severe form of the disease is associated with a 1.5 increased risk of low birth weight. We review common therapies and medications used in the treatment of psoriasis and their safety in pregnant patients that seek treatment.
Most topical medications discussed below for the treatment of psoriasis during pregnancy are, for the most part, safe. Lactation safety will be discussed individually for each class of medication. Lactation safety categories are designated L1-L5 according to Dr. Hale’s classification system. L1 = Safest, L2= Safer, L3= Moderately Safe, L4 = Possibly Hazardous, L5 = Contraindicated.
Current guidelines set forth by the National Psoriasis Foundation suggest using mild-to-moderately potent steroids preferentially during pregnancy. Reports of low birth weight have been cited in the literature with the use of very strong steroids when used in large quantities (over 300 grams throughout the pregnancy). No other negative impacts on the pregnancy were reported in any of the studies reviewed. These should be the first-line medications for mild cases of psoriasis during pregnancy.[2, 7] Corticosteroids have been designated L1-L3 and can be applied in appropriate quantities, even to the nipple, except for class I (strongest class) steroids during lactation.
This class of drugs includes medications such as tacrolimus and pimecrolimus. When taken in the oral form, these are known to be related to low birth weight and prematurity. In the topical form of these medications, compared to topical steroids, we do not have as many studies to support safe use in pregnancy. However, several individual reports of using these topical medications during pregnancy reported no adverse fetal outcomes. Recommendations indicate that these should be used as second-line agents if topical corticosteroids cannot be used. They can also be considered when treating areas of thinner skin such as the face or genitals.[2, 8] For breastfeeding mothers, they are categorized as L2 and should not be used on the nipple under any circumstance because oral absorption in the infant could be high.
There is limited human evidence for this treatment modality during pregnancy. Current guidelines suggest that this should be avoided in both pregnancy and lactation as there have been reports of birth defects in animal studies.
This is a vitamin-D based topical medication commonly used in psoriasis. It is considered safe to use as a second-line agent in small areas of the body and in small doses (<100 g/wk of 0.05% solution) during pregnancy. In animal studies at very high doses of topical application, the skeleton of the fetus was affected, but the same has not been demonstrated in humans and the doses used for psoriasis are usually smaller. This is considered L3 in lactation safety and is safe to use if the body surface area is limited to <20%.[2, 8]
Side note: The above information pertains to calcipotriene only. However, calcitriol is in the same class of medication and the same level of caution should be exercised when using topical calcitriol in the treatment of psoriasis during pregnancy.
Ultraviolet type B (UVB) light therapy (both narrow and broad band) is perhaps the best option for the treatment of psoriasis in pregnant women. There are a few side effects particular to pregnant women that need to be considered when treating with phototherapy. There is the risk of worsening any skin darkening occurring on the face since this is common during pregnancy (known as melasma/chloasma). Also, UV light may degrade folic acid levels, and folic acid is important for proper spinal cord development of the baby in the first trimester. This highlights the importance of shielding the face during UV therapy, and to supplement the mother with folic acid in her prenatal vitamin.[2,10]
PUVA (psoralen + Ultraviolet type A) light therapy should be avoided during pregnancy. If given to a lactating mother, it is necessary to pump and discard the milk for one day after therapy to prevent photosensitizing the nursing baby.
Most systemic medications should be used judiciously, weighing the risks and benefits during pregnancy, due to well-known adverse impacts on the fetus or uncertainty surrounding their effects.
A few examples of biologic drugs include etanercept, adalimumab, infliximab, and ustekinumab. Although there are quite a few theoretical risks with use during pregnancy, successful and safe treatment in the pregnant population has been reported. Therefore, some experts recommend that for women already on these agents with severe psoriasis who become pregnant and experience no adverse events, the continuation of treatment is an option. These are all considered L3 for lactation safety, except for infliximab which is considered L2. These are seemingly safe medications during breastfeeding.
Since there are some risks to fetal growth and high blood pressure in the mother, this should be avoided. However, if the pregnant woman is experiencing severe psoriasis and is on medication with no adverse events reported, therapy may be continued. For lactation, this is considered L3 but should be avoided or blood levels of the drug should be monitored in the baby.[2.8]
Methotrexate is Pregnancy Category X. This medication should not be used and is completely contraindicated in pregnancy and lactation (L5).
The use of apremilast in pregnant women with psoriasis has not been published in the current literature. Although this is generally a relatively safe drug in the non-pregnant population, there is a concern for exacerbation of gastrointestinal symptoms (nausea and vomiting) in pregnancy. A few animal studies have reported negative side effects including an increase in abortions with increasing doses of the drug, but this has not been demonstrated in humans. No definitive recommendations can be made at this time regarding the use of this drug during pregnancy.