Parents Who Make Their Children Ill : Health: Their condition is called Munchausen syndrome by proxy and the motive apparently is animosity to doctors. Ten percent of their child-victims die.

By the time he was 2 1/2, Michael Herzog Jr. had been hospitalized more than 20 times, and his mother kept detailed records and worked hard with doctors trying to find the cause of his ailments.

Now, authorities say, the mysterious illnesses can be traced to his mother, Peggy Herzog. She is accused of infecting her son by injections and other means, and doctors believe the case is an extreme example of a psychological disorder called Munchausen syndrome by proxy.

The disorder is a variant of Munchausen syndrome, in which a person fakes disease to get medical care. In Munchausen by proxy, first described in 1977, a parent produces disease or the appearance of disease in a child, then acts admirably dedicated and worried.

“It’s an extremely rare condition and it requires that a physician suspect it. If the deception is done well enough, it may take us forever to suspect it,” said Dr. Randell Alexander, associate professor of pediatrics at the University of Iowa.

Doctors last fall began to suspect that Herzog was causing her son’s illnesses, the court records say, but authorities were not notified until the boy complained in February to a family friend that his thigh was sore. “Mommy gave me shots,” he said.

The boy was removed from the family’s home in Hugo and has recovered his health, authorities said.

Herzog, who has refused to comment, pleaded guilty on June 6 to felony assault in the third degree, in exchange for dismissal of a misdemeanor fifth-degree assault charge.

Sentencing is scheduled for Aug. 5. She faces up to five years on probation and no more than 30 days in jail, First Assistant Washington County Atty. Richard Hodsdon said.

Washington County District Court records say she told police she had injected “just water” into her son’s leg. She told police that her husband, Michael Sr., was unaware of what she had done.

According to court records, police said that Herzog was unable to explain why his wife might have injected their son, saying, “She spoils him. Why would she do this?”

Munchausen by proxy leaves experts with lots of questions.

Alexander, a nationally recognized authority on Munchausen by proxy, said at least 200 cases have been described in medical literature. He suspects that many cases go undiagnosed.

In 1988, a South St. Paul woman pleaded guilty to assaulting her 1-year-old son by pressing his face to her body in a hospital sleep laboratory. In January, a Princeton man pleaded guilty to assaulting his 9-month-old daughter by pushing her face into a hospital bed mattress until she stopped breathing.

Other suspected cases include that of a Wayland, Mich., woman who police say confessed late last year to killing three of her babies and a woman found guilty in Des Moines of child endangerment after evidence showed she cut off air to her 3-year-old son at least nine times and then contended that the boy had seizures.

About 10% of the children who are victims of people with Munchausen by proxy die, Alexander estimated. An additional 60% to 70% become ill, he said.

“In all cases, it’s a combination of physical abuse and neglect as the parent gets the doctor to poke the child with needles, do all the things they would do if the child really had the symptoms,” Alexander said. “It’s neglect because they are not attending to the child’s health and emotional needs.

“The description is that they’d be the last one you’d ever think of (who) would do such a thing. The mother who’s very friendly, is always there for her child,” Alexander said. “You can’t tell if they have it by any psychological test, and you can’t tell if they’ve gotten any better because you didn’t have a marker in the first place.”

Those with Munchausen by proxy appear to have an unconscious resentment toward doctors and do what they think will give them more power than the doctors, said Theodore Nadelson, chief of psychiatry at the Veterans Administration Medical Center in Boston.

“Such people are angry, resentful, and alternately magnify others’ importance and will tear them down,” Nadelson said. “They have a need for power, a need for revenge.”

Nadelson is pessimistic about treatment.

“My view is that patients who are doing it are so entrenched and have such a characteristic of lying that you really can’t treat them. They lie to doctors, and there’s nothing to stop them from lying” about their treatment, he said.

Nadelson and Alexander agreed that the first step typically must be getting a court order to keep the adult away from the child.

“You try to neutralize them,” Nadelson said. “You expose them, then you also warn other hospitals about them.”