Cellulitis is not contagious. A boil is not cellulitis.
Cellulitis in an infection of the deeper lays of the dermis by the staph bacteria, and it can also happen from infection from the Group A Streptococcus.
The same bacteria can cause an infection on the top layer of skin called impetigo and this is very contagious.
Cellulitis is usually got from a bacteria entering a puncture to the skin. This can be from surgical cuts, from being bitten by cats or dogs, being stung and from open eczema. Sometimes the infection is nowhere near the puncture to the skin.
Cellulitis is extremely painful and painful to touch, there may be fever and chills and the area will be very red and inflamed. It is treated by antibiotics if not too advanced.
If your uncle's boil oozed any pus and you touched that then you will have picked up bacteria. But not necessarily got infected.
Your uncle needs to see his doctor with regard to his boils. Bacteria from boils can spread internally. The doctor may need to lance and drain the boil and may also prescribe an antibiotic, a drawing ointment, or an antibacterial cream.
I start out with a abscess that was opened with a needle (doctor thought it was a boil but it wasn't) it spread through my bloodstream and turned into MRSA. It's contagious if he had a opened wound and you came in contact with his blood or other bodily fluids. If you are concerned you can have a lab test ran to have your doctor run a swab test of your nose, groin and armpits. I got mine just from going to the hospital for surgery.
no ..not contagious at all ....