Comment
Generalized pustular psoriasis of pregnancy is a rare condition that typically occurs in the third trimester but also can start in the first and second trimesters. It may result in maternal and fetal morbidity by causing fluid and electrolyte imbalance and/or placental insufficiency, resulting in an increased risk for fetal abnormalities, stillbirth, and neonatal death.3 In subsequent pregnancies, GPPP has been observed to recur at an earlier gestational age with a more severe presentation.1,3
Generalized pustular psoriasis of pregnancy usually involves an eruption that begins symmetrically in the intertriginous areas and spreads to the rest of the body. The lesions present as erythematous annular plaques with pustules on the periphery and desquamation in the center due to older pustules.1,3 The mucous membranes also may be involved with erosive and exfoliative plaques, and there may be nail involvement. Patients often present with systemic symptoms such as fever, malaise, diarrhea, and vomiting.1 Laboratory investigations may reveal neutrophilic leukocytosis, high erythrocyte sedimentation rate, hypocalcemia, and hypoalbuminemia.4 Cultures from blood and pustules show no bacterial growth. A skin biopsy is helpful in diagnosis, with features similar to generalized pustular psoriasis, demonstrating spongiform pustules containing neutrophils, lymphocytic and neutrophilic infiltrates in the papillary dermis, and negative direct immunofluorescence.3
The differential diagnosis of GPPP includes subcorneal pustular dermatosis, dermatitis herpetiformis, herpes gestationis, impetigo, and acute generalized exanthematous pustulosis.1,3 Due to concerns of fetal implications, treatment options in GPPP are somewhat limited; however, the condition requires treatment because it may result in unfavorable pregnancy outcomes. Topical corticosteroids may be an option for limited disease.5,6 Systemic corticosteroids (eg, prednisone 60–80 mg/d) were previously considered as first-line agents, although they have shown limited efficacy in our case as well as in other case reports.7 Their ineffectiveness and risk for flare-up after dose tapering should be kept in mind when starting GPPP patients on systemic corticosteroids. Systemic cyclosporine (2–3 mg/kg/d) may be added to increase the efficacy of systemic steroids, which was done in several cases in literature.1,6,8 Although cyclosporine has been classified as a pregnancy category C drug, an analysis of pregnancy outcomes of 629 renal transplant patients revealed no association with adverse pregnancy outcomes compared to the general population and no increase in fetal malformations.9 Therefore, cyclosporine is a safe treatment option and was classified as a first-line drug for GPPP in a 2012 review by the National Psoriasis Foundation Medical Board.2 Narrowband UVB also has been reported to be used for the treatment of GPPP.10 Methotrexate and retinoids have been used in cases with lesions that persisted postpartum.1
Anti–tumor necrosis factor (TNF) α agents are another effective option for treatment of GPPP. Anti-TNF agents are classified as pregnancy category B due to results showing that anti-mouse TNF-α monoclonal antibodies did not cause embryotoxicity or teratogenicity in pregnant mice.11 Although Carter et al12 published a review of US Food and Drug Administration data on pregnant women receiving anti-TNF treatment and concluded that these agents were associated with the VACTERL group of malformations (vertebral defects, anal atresia, cardiac defect, tracheoesophageal fistula with esophageal atresia, cardiac defects, renal and limb anomalies), no such association was found in further studies. A 2014 study showed no difference in the rate of major malformations in infants born to women who were treated with anti-TNF drugs compared to the disease-matched group not treated with these agents and pregnant women counselled for nonteratogenic exposure.13 The same study detected an increase in preterm and low-birth-weight deliveries and suggested this might be caused by the increased severity of disease in patients requiring anti-TNF medication. The British Society of Rheumatology Biologics Register published data on pregnancy outcomes in 130 rheumatoid arthritis patients who had been exposed to anti-TNF agents.14 The results suggested an increased rate of spontaneous abortions in women exposed to anti-TNF treatment around the time of conception, especially in those taking these medications together with methotrexate or leflunomide; however, results also indicated that disease activity may have had an impact on the rate of spontaneous abortions in these patients. In a 2013 review of 462 women with inflammatory bowel disease who had been exposed to anti-TNF agents during pregnancy, the investigators concluded that pregnancy outcomes and the rate of congenital anomalies did not significantly differ from other inflammatory bowel disease patients not receiving anti-TNF drugs or the general population.15
In 2012, the National Board of the National Psoriasis Foundation put infliximab amongst the first-line treatment modalities for GPPP.2 In one case of GPPP in which the eruption persisted after delivery, the patient was treated with infliximab 7 weeks postpartum due to failure to control the disease with prednisolone 60 mg daily and cyclosporine 7.5 mg/kg daily. Unlike our patient, this patient was only started on an infliximab regimen after delivery.16 In another case reported in 2010, the patient was started on infliximab during the postpartum period of her first pregnancy following a pustular flare of previously diagnosed plaque psoriasis (not a generalized pustular psoriasis, as in our case).17 As a good response was obtained, infliximab treatment was continued in the patient throughout her second pregnancy.
Our case is unique in that infliximab was started during pregnancy because of intractable disease leading to systemic symptoms. Our patient showed an excellent response to infliximab after a 10-week disease course with repeated flare-ups and impairment to her overall condition. Delivery occurred at 36 weeks’ gestation due to suspected intrauterine growth retardation; however, the neonate was born with a 5-minute APGAR score of 10 and required no special medical care, which suggests that the low birth weight was constitutional due to the patient’s small frame (her height was 4 ft 11 in). The breast milk of patients with inflammatory bowel disease has been detected to contain very small amounts of infliximab (101 ng/mL, about 1/200 of the therapeutic blood level).18 Considering the large molecular weight of this agent and possible proteolysis in the stomach and intestines, infliximab is unlikely to affect the neonate.15 Thus, we encouraged our patient to breastfeed her baby. A case of fatal disseminated Bacille-Calmette-Guérin infection in an infant whose mother received infliximab treatment during pregnancy has been reported.19 It has been suggested that live vaccines should be avoided in neonates exposed to anti-TNF agents at least for the first 6 months of life or until the agent is no longer detectable in their blood.15 We therefore informed our patient’s family practitioner about this data.
Conclusion
We report a case of infliximab treatment for GPPP that was continued during the postpartum period. Infliximab was an effective treatment option in our patient with no detected serious adverse events and may be considered in other cases of GPPP that are not responsive to systemic steroids. However, further studies are warranted to evaluate the safety and efficacy of infliximab treatment for GPPP and psoriasis in pregnancy.