Whooping cough eight weeks, or sometimes longer. A gradual transition then occurs to the convalescent stage, which usually lasts one to four weeks. This stage is marked by a decrease in paroxysms of coughing, although paroxysms may occur with subsequent respiratory infection for many months after the onset of pertussis. The time between exposure and the development of symptoms is on average 7–14 days (range 6–20 days), rarely as long as 42 days. Pertussis is caused by the bacterium "Bordetella pertussis". It is an airborne disease (through droplets) that spreads easily through the coughs and sneezes of an infected person. Uncertainties have
Blount's disease Blount's disease Blount's disease is a growth disorder of the tibia (shin bone) that causes the lower leg to angle inward, resembling a bowleg. It is also known as "tibia vara". It is named after Walter Putnam Blount (1900–1992), an American pediatric orthopedic surgeon. It has also been known as Mau-Nilsonne Syndrome, after C. Mau and H. Nilsonne, who published early case reports of the condition. Bowing of one or both legs that may: Failure to treat Blount's disease may lead to progressive deformity.Blount's disease may come back after surgery, especially in younger children. Because of the bowing, a leg-length