An outbreak of scabies has been reported in the Radnor Township School District.

Seventeen cases of the itchy and contagious skin condition were identified last week, according to district officials. Almost all were at the middle school, but one case has been confirmed at Radnor Elementary School.

“We wanted to make our entire district community aware of this situation to ensure you are alert to the signs and symptoms, and to recommend you consult your family health-care provider should you or your child(ren) present symptoms,” wrote Todd Stitzel, director of human resources for the school district, in an email that went out to parents Friday.

District spokesperson Michael Petitti said school custodians sanitize the schools’ restrooms, wipe down desk and door handles, and mop nightly, and clean cafeteria tables after each lunch.

“As an extra precautionary measure, our custodians are taking special care to treat common surfaces in classrooms of the affected schools,” Petitti added.

Scabies is caused by mites that burrow under the skin and lay eggs. The condition is characterized by intense itching, often worse at night, and a pimple- or blister-like rash that can affect many parts of the body, according to the federal Centers for Disease Control and Prevention. Those areas include between fingers, wrists, armpits, elbows, the waist, buttocks, shoulders, and genitals. In babies and very young children, the affected areas tend to be the head, face, neck, palms, and soles of feet.

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Scabies is highly contagious and is usually spread by skin-to-skin contact with people who have the condition. However, it can also be spread indirectly by sharing clothing, towels, or bedding.

It usually takes two to six weeks for symptoms to appear after a person is first infested with the scabies mites, according to the CDC. For repeat cases, the symptoms reappear in one to four days.

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Scabies should be treated with prescription topical ointments that can kill the mites. Bedding, clothes, and towels used by infected individuals should be washed in hot water and dried in a hot dryer or dry cleaned.

In the district-wide email, parents were advised that students with scabies symptoms will be excluded from school unless they have a note from a health-care provider that they are under treatment. The email also said affected skin areas must be covered in order for the students to be allowed to return to school.