A 3-year-old Anne Arundel County boy with herpes finally started school today -- alone. The boy's five classmates all stayed home, apparently in protest by their parents, who expressed fear that the children could be infected with the viral disease. The boy's teacher also stayed out, and a substitute teacher was called in.

"I do not want to expose my children to active lesions and we have no way of knowing when this child's lesion pattern is active or not active," said one parent, who asked not to be identified. Teacher Jane Timberg said, "I feel if I were in contact with him I would be at risk. It's a very hands-on program."

The boy, who has an unrelated speech disability, has been at the center of a two-month controversy over whether he should be allowed to attend a special education class at Pasadena Elementary School. The conflict escalated today, when county School Superintendent Robert C. Rice insisted the class will remain open to the boy, and the president of the county teachers' union said he will seek a court injunction to keep the boy from attending classes.

Herpes includes a range of contagious skin disorders that cause lesions or blisters on the skin. Type I, the more common form, causes cold sores and shingles. Type II is known as genital herpes.

The boy is believed to have contracted the disease on his hands and back shortly after birth, but he has not been tested to determine which type he has. County health officials say that is because it would not matter; both types can be equally harmful and can cause nerve damage or blindness, if the eyes are infected.

Neither of his parents nor his two siblings have the disease, health officials said.

The boy's teacher said she took sick leave today because she has been diagnosed by two doctors as having eczema, a skin irritation that causes breaks in the skin that would make her susceptible to catching the herpes virus if the boy had an open lesion.

She added that if the boy attends school Tuesday she will again call in sick. Meanwhile, she has requested a transfer to another school.

A county health nurse checked the boy this morning and found no lesions, school officials said.

Parents of the five children who are enrolled in the boy's 2-hour, 15-minute morning class and eight children who attend an afternoon session all kept their children home today, according to C. Berry Carter, deputy superintendent of Anne Arundel County Schools. A total of 78 out of 331 students who attend special classes and grades K-5 at the school were absent today, or 32 percent of the student population, arter said. The normal is 10-15 percent for this time of year.

Parents whose children are enrolled in the morning class are to meet Tuesday night to discuss future action. They previously asked the school system to provide a nurse to screen the boy daily for lesions. If there are lesions, they want him returned home until he is no longer contagious, the parent said.

School policy would allow the boy to attend classes with active lesions if they are covered. The county has declined to make a nurse available every day for screening him.

Phoned-in threats that "there would be trouble" never materialized, said Carter, who monitored the special education class, but a police car sat in front of the school and a police officer stood inside the entrance as a precaution.

The boy, described by Carter as "a charming little youngster," spent his morning putting rocks in a fishbowl, filling it with water and playing with a goldfish, said Carter.

State Superintendent David G. Hornbeck today declined a request from the union that he intervene and block the child's entry. Under a 1975 federal law, the county must provide special education to any child 3 years old or older with a learning disability. It is not mandatory, however, that the children attend.