Scabies Infection While Expressing Human Milk for Critically Ill Infants: Is It Safe?

Introduction

Scabies is an ectoparasitic skin infection caused by Sarcoptes scabiei var. hominis that affects 200–300 million people annually worldwide. ¹ Scabies is transmitted primarily by skin-to-skin contact and can also be transmitted via fomites. ² Clinical manifestations include multiple erythematous skin lesions, burrows, and intense pruritus that is usually worse at nighttime. ¹ There is little published literature regarding active scabies infection around the areola and its impact on breast milk feeding. Additionally, there is few data on the impact of human milk expression with active scabies infection for a hospitalized infant in the neonatal intensive care unit (NICU). One case report presents an infant with facial rash after breastfeeding from infected nipples, but no other reports have been documented to our knowledge. ³ Published studies regarding treatment options for lactating women are limited, and we were unable to find any published literature to guide care for expression of human milk in mothers with active scabies infection who have hospitalized children in the critical care setting. ⁴

In this case report, we present a female infant born at term to a mother with an active scabies infection of the breast and desire to express human milk to feed to the newborn.

Case

A female infant was born at 37-week 2-day gestation to a now G5P5 mother via repeat C-section. The prenatal course was uncomplicated with normal maternal labs during pregnancy other than an elevated 1-hour glucose tolerance test followed by a normal 3-hour glucose tolerance test. Second trimester anatomy ultrasound was normal. Labor and delivery course was also uncomplicated, although polyhydramnios was noted at the time of C-section by the obstetrician.

At delivery, the patient had respiratory distress and abdominal distension. She was placed on continuous positive airway pressure (CPAP) and transferred to the NICU. Initial abdominal X-ray showed a normal gas pattern on the left and absent gas on the right. The patient was to take nothing by mouth (NPO) and was started on maintenance IV fluids and empiric antibiotics with gentamicin and ampicillin. Because of the abdominal distension, the patient was transferred to a level-4 NICU. Abdominal X-ray showed gas filled bowel loops only in the left upper quadrant, and abdominal ultrasound showed a prominent cystic structure with trace free fluid. Upper gastrointestinal (GI) series indicated that the duodenal jejunal junction did not rise to the level of the duodenal bulb, which was concerning for malrotation.

On day of life 2, pediatric surgery was consulted, and an exploratory laparotomy was performed, which revealed a meconium pseudocyst and twisting of the small bowel. Twenty-five centimeters of bowel of was resected, and the bowel was left in discontinuity due to coagulopathy. A second exploratory laparotomy was performed on day of life 3, where an additional 4 cm of bowel was resected, and an ileostomy and mucous fistula were created. Reanastomosis with gastric tube (GT) placement was performed 6 weeks later. The hospital course was further complicated by septic shock secondary to bacteremia 8 days postoperatively from reanastomosis and malnutrition with poor growth concerning for cystic fibrosis. Cystic fibrosis transmembrane conductance regulator (CFTR) complete gene sequencing confirmed a heterozygous mutation.

In contrast, the maternal postpartum course was uncomplicated. At 35 weeks gestation, the patient's mother was diagnosed with scabies infection of the breast, back, neck, and interdigit areas. She was treated with permethrin topical cream for a total of 10 days, but the infection persisted. At the time of delivery, the patient's mother had an active scabies infection around the nipple area and her hands. During the patient's NICU admission, her father also had diffuse pruritus from active scabies lesions and one of the patient's siblings had active lesions. The patient's mother, father, and sibling with scabies were treated with oral ivermectin 12 days after the patient's birth and completed the course of treatment. The patient's mother and sibling reported that they no longer had a rash 8 days after treatment, but the patient's father continued to have a rash on his hands.

The family lives in a crowded environment and describes their home as a 2-bedroom apartment that houses the patient's mother, father, and 4 siblings (6-year-old, 4-year-old, and a set of 2-year-old twins). The family has been managing recurrent outbreaks of scabies in their household for the past 2 years. They report prior treatment with both permethrin and ivermectin but were unsure of the previous duration of treatment. Interventions the family has tried include vacuuming their carpet, mattress, and vehicle, placing items in the sun, and washing with hot water. Their apartment manager is not amenable to assisting the family with pest control.

Lactation specialists were consulted throughout the patient's hospital course. The patient's mother expressed desire to breastfeed and was pumping consistently during the day when contacted by lactation services 2 days after the patient's birth. Her mother has breastfed before, but this was her first time pumping human milk. Given the importance of breast milk for infants and the importance of enteral feeding after bowel resection, ⁵ continued expression of breast milk by pump was encouraged. A breastfeeding medicine physician was consulted regarding the safety of using expressed human milk given active scabies infection of the breast, and recommended use of maternal human milk.

At 3 months of age, the patient was downgraded from the NICU and transferred to the Pediatric Gastroenterology service. She was NPO until 10 days after birth when enteral feeds with expressed breast milk were started with supplementation via parenteral nutrition. Infant formula was added to the feeds as needed when the supply of expressed breast milk was low. After GT placement, continuous GT feeds were advanced slowly as parenteral nutrition was weaned. Feed advancement was slow because of complications secondary to gastrointestinal dumping. Of note, the patient was also on pancreatic enzymes for 3 weeks following confirmation of heterozygous CFTR gene mutation, but fecal testing following replacement showed normal pancreatic elastase and fecal fat levels, so the pancreatic enzymes were discontinued.

The patient's diet at the time of transfer was continuous tube feeds with a combination of expressed breast milk and infant formula and a trial of up to 1 hour of by mouth (PO) feeding every 6 hours. Vitamins A, D, E, and K supplementation were started following transfer to the Pediatric GI service. There was not any transfer of scabies infection to the newborn and no concern for toxicity, given maternal treatment with ivermectin while expressing milk. The patient was discharged home at 3 months and 10 days with a GT and instructions for continuous formula and expressed breast milk feeds with pauses every 8 hours for a trial of up to 1 hour of PO feeding. The family reports that the patient is doing well and is being followed by Pediatric Gastroenterology, Pulmonology, and Surgery in their outpatient clinics.

Discussion

There are limited studies available on the treatment of scabies skin infections during pregnancy and lactation. There is also limited information about the risk of scabies transmission from infected nipples to breastfeeding infants. One case report from Germany presented an infant with facial papules and generalized dermatitis via transmission from infected nipples during breastfeeding. ³ Information is also limited about the transmission of scabies mites directly into breast milk. However, based on the mechanism of infection, there is theoretically no risk of transmission via human milk. Female mites burrow into the stratum corneum layer of the skin and cause a hypersensitivity reaction. ² Lactocytes, which synthesize and secrete milk, line the breast alveoli, which are located deep to the epidermis. ⁶ Since the mites do not burrow deep enough to reach the lactocytes, the risk of transmission of mites or their eggs while expressing milk is unlikely and has not been described.

Given the risk for possible transmission and the psychosocial factors related to scabies infection such as pruritus leading to worsened sleep, treating scabies during pregnancy and breastfeeding is important. ⁴ Treatment with scabicides has not been well studied during lactation, and there is limited available supporting evidence for its safety and efficacy during this time specifically. ⁷ Treatment with topical permethrin is first line during pregnancy, and lactation as it has low systemic absorption and is rapidly metabolized to inactive compounds. ⁸ In a follow-up telephone study, 5 breastfeeding mothers reported no adverse effects with the use of topical permethrin for their breast-fed infants, but there have been no further studies to support this. ⁹ For refractory cases, oral ivermectin is an option as it is considered compatible during breastfeeding. ⁴ Ivermectin is poorly excreted into breast milk, and any amount ingested by the infant is small with no adverse effects. ¹⁰ One study's authors did not observe any serious adverse effects during a 3-year period of ivermectin use in lactating mothers in parasitic endemic areas. ¹¹

Additionally, the treatment of refractory scabies affecting the nipple region in this case has demonstrated the importance of continuing to research this topic for further education and clinical application. Especially in the intensive care setting where evidence has suggested that as many as 50% of critically ill children are vulnerable to malnutrition, being able to provide human milk for these infants is of great importance. ¹²

Conclusion

This case report adds to the limited information that is known about risk of transmission of scabies infection in the hospitalized breastfed infant. As human milk is the ideal food for all infants, especially those who are critically ill and in need of nutritional support, further research on the impact of scabies infection of the nipple region and scabies treatment for the breastfeeding infant is needed.