Perianal hard knot pain and itching later become bigger and softer may be due to the emergence of perianal abscess, from the initial redness and swelling of the hard knot developed into pus and soft, at this time the need for surgical incision and drainage. 1. Most of the perianal abscesses are due to the obstruction of the anal crypts leading to bacterial aggregation and infection, manifested as persistent pain and swelling around the anus, accompanied by generalized fever, chills, and fatigue in severe cases. 2. The early stage of perianal abscess is a hard knot with obvious tenderness, not yet formed abscess pus, you can take oral or external antibiotics such as erythromycin, levofloxacin, etc.. 3. As the disease progresses abscess maturity, manifested as a soft lump formation of pus, touching the obvious fluctuation, this time should be under local anesthesia as soon as possible incision and drainage, so that the pus drainage smooth, so as to avoid the spread of infection in the perianal area. When there are hard nodules in the perianal area, you should go to the hospital for treatment in time to avoid delaying your condition.