A 7-month-old girl at an unlicensed home day care on Aliamanu Military Reservation died in February of an overdose of an antihistamine.

A Honolulu medical examiner determined the cause of death as “diphenhydramine toxicity,” finding a fatal level of the active ingredient in Benadryl in the child’s blood.

Toxicology tests showed “positive for diphenhydramine (Benadryl) at 2400 ng/mL (nanograms per milliliter) of diphenhydramine in the blood. The average blood diphenhydramine concentrations reported in fatal overdoses were 1400 ng/mL in infants,” according to court documents released Monday.

Dixie D. Villa, also known as Denise Villa, made her initial court appearance before Judge Frances Wong at Family Court in Honolulu District Court on Monday after she was charged Saturday with manslaughter in the death of Abigal Lobisch.

Villa was Lobisch’s babysitter for about four to five months. A police arrest log listed Villa’s age as 40, but she told the judge in her initial appearance that she is 41.

Villa clasped her hands in front of her as she stood in court next to her attorney, David Hayakawa.

Wong set Villa’s preliminary hearing for Aug. 2. Her bail is set at $1 million.

The unattended death was reclassified as manslaughter July 16 after Honolulu police received an autopsy report from the Honolulu Medical Examiner’s Office indicating high levels of diphenhydramine in Lobisch’s blood.

The antihistamine is used to relieve symptoms of allergy, hay fever and the common cold but not recommended for young children.

The medical examiner noted in the autopsy report that children younger than age 6 should not be given diphenhydramine without consulting a physician.“Per the over the counter label, when used for self-medication, diphenhydramine should not be used in children (younger than) 6 years, to make a child sleep, or with any other diphenhydramine-containing products (including topical products).”

At about 10:45 a.m. Feb. 23, Lobisch’s mother, Anna Lobisch, left her baby and her 2-year-old son with Villa at a hotel room at the Aulani, a Disney Resort &Spa in Ko Olina, where she was to care for them until Feb. 24.

Villa’s two children plus Lobisch and her brother spent the day at the pool, where Lobisch’s mother received text updates throughout the day from Villa including photos of her daughter at Aulani.

Police said Villa left the hotel with the children at about 5:30 p.m. and returned to her home at 4675 Ke St. at the Aliamanu Military Reservation.

According to documents, she applied a Bath &Body Works lotion on the children for a sunburn and fed them before the children went to bed at 10 p.m.

Villa told police Lobisch did not wake up throughout the night. Though the baby usually woke up during the night, Villa said she did not think it was unusual that she did not wake up that night because she thought Lobisch was tired from being in the sun all day.

Sometime after 8 a.m. the next morning, Villa noticed Lobisch lying facedown and that her skin appeared “splotchy” and “cold to the touch.” Police said she called 911 and performed cardiopulmonary resuscitation on the baby until emergency responders arrived.

Lobisch’s mother said she texted Villa at 8:08 a.m. to confirm the time she was going to pick up her children. “Villa responded for Lobisch to ‘come now.’”

Lobisch was taken to Tripler Army Medical Center and pronounced dead at 8:55 a.m.

Lobisch’s mother told police her baby was healthy before she dropped off her children with Villa at Aulani.

The Army oversees Aliamanu Military Reser­vation. U.S. Army Hawaii spokesman Dennis Drake declined to comment on the manslaughter charge against Villa, saying they do not comment on ongoing investigations.

Manslaughter is a Class A felony that is punishable by up to 20 years in prison.