A fever with no source
Weeks of fevers, night sweats, or fatigue after a negative workup elsewhere. The job is to widen the differential and order the right test rather than another round of the same ones.
Mark N. Sayegh, MD — Infectious Disease
Answers for infections that haven’t resolved.
A consultative practice in Scarsdale for adults with persistent, recurrent, or hard-to-identify infections — and for the primary care physicians and hospitalists who refer them. Seen by appointment on Thursdays.
Three reasons people are sent here
An infection that keeps coming back
Recurrent skin, urinary, sinus, or bone and joint infections. Recurrence usually means something structural, something resistant, or the wrong drug for the right bug.
Discharged on IV antibiotics
Hospital follow-up for patients finishing a long antibiotic course at home, with the lab monitoring and line oversight that course requires.
Westchester has a tick problem
Lyme disease, babesiosis, and anaplasmosis are all endemic here, and they overlap: one tick bite can transmit more than one organism, and the second infection is what gets missed when symptoms persist after treatment.
The practice evaluates suspected tick-borne illness, interprets equivocal serology, and sorts genuine persistent infection from post-treatment symptoms — two situations that look alike and are managed very differently.
For referring physicians
Consultation notes go back to the referring office, and urgent questions get a same-day call back. Records can be sent ahead of the visit by fax to 914-222-8761.
Dr. Sayegh is affiliated with St. John’s Riverside Hospital in Yonkers. Full credentials are on the about page.
Where to find us
- Address
- 340 Ardsley Road, Suite 2A
Scarsdale, NY 10583 - Telephone
- 914-222-1486
- Fax
- 914-222-8761
- Office hours
- Thursday, 9:00 am – 5:00 pm