By request, I am posting about a disease called puppy strangles, otherwise known as juvenile cellulitis. While we don't see cases of it every day, it is nonetheless not rare.
Affected puppies are usually between one and four months of age. with symptoms that are often quite shocking in appearance. They include a swollen face, ears, muzzle, and spectacularly enlarged lymph nodes. The symptoms are consistent with other diseases and must be differentiated from a severe bacterial or fungal infection and mange (Demodex or Sarcoptes mites under the skin). Puppy strangles can be quite painful, unlike the other diseases just mentioned.
While it may appear that these dogs have some sort of infection, true puppy strangles is an auto-immune disease, meaning that the puppy's own immune system has, for some reason, gone a "little haywire". Therefore, treatment involves the use of prednisone, as an immunosuppressant, for cure. Within one to two weeks of treatment, affected puppies respond very favorably. The disease is curable and does not recur.
Puppy with juvenile cellulitis, or strangles (photo from the Pet Health Library).