A lawsuit has been filed against the Pegasus School in Huntington Beach by an HIV-positive teacher who claims he was harassed and then forced to quit under threat.

Science teacher and Irvine resident Matthew Edmondson is accusing the head of the school and its middle school director of discriminating against him, creating a hostile work environment and verbally abusing him, among other work-related violations. He is demanding a jury trial.

Edmondson's allegations were denied by Head of School John Zurn, who said Pegasus will defend itself. Zurn said he could not comment on the details of the case because the school is being sued.

"Not only was I forced out of an almost 10-year career, my students really suffered," Edmondson said in a prepared statement. "We were halfway through the year, in the midst of an exam and other work. "We both lost a lot — I lost my job and health-care benefits, they lost their teacher during a busy time in the school year."

Edmondson was first hired by the private pre-kindergarten-through-eighth-grade school in 2002 to teach sixth- and seventh-grade science. He left in 2006 to teach at a private Catholic school in Texas and was recruited to return to Pegasus by the school's then-middle school director to teach eighth-grade science.

In October of last year, Edmondson's doctor switched his HIV medication.

The medication had side effects that caused him muscle pain, numb or cold feelings in his arms and legs, headache, stomach pain and nausea, among other symptoms, the lawsuit said. Edmondson was forced to call in sick, but never exceeded the 10 days he was allowed by his contract.

The lawsuit acknowledged that Edmondson sometimes got to his classroom a few minutes late because of extended visits to the restroom, but stressed that he remained committed to his students and the school.

Most of the school staff and administration knew of his HIV status, but it never became an issue until Zurn and middle school director Joseph Williamson, who are fairly new to the school, began discriminating against him for having the disease and for his sexual orientation and then forced him to quit, according to the lawsuit.

Zurn and Williamson began questioning Edmondson about his absence in February. Several meetings were scheduled between February and March where the two allegedly verbally abused him despite Edmondson's repeated attempts to explain the side effects, which were subsiding over time, and apologies for being sick, the lawsuit said. The two administrators dismissed his explanations as excuses.

They also questioned his teaching method despite having favorable reviews and feedback during his entire time at Pegasus, the lawsuit said.

When the administrators scheduled another random meeting with him, Edmondson, in an attempt to protect himself, tried to record the conversation with his iPhone, without Zurn and Williamson's knowledge. The recording was not audible, the lawsuit said.

When Zurn and Williamson found out, they scheduled another meeting, handed him a confidential release letter and told him he had two days to sign it or the school would have to report his attempt to record the conversation to the Orange County district attorney's office, the lawsuit said.

Edmondson asked for more time to consult with an attorney, but the request was denied.

Afraid he would be arrested or charged, Edmondson said he felt he had to sign the letter, according to the lawsuit.

mona.shadia@latimes.com

Twitter: @MonaShadia