slurred speech, and personality changes. initial episodes of arf, as well as recurrences, can be prevented by treatment with appropriate antibiotics. it is important to distinguish arf from rheumatic heart disease. arf is an acute inflammatory reaction with pathognomonic aschoff bodies histologically and rhd is a non-inflammatory sequela of arf. post-streptococcal glomerulonephritis post-streptococcal glomerulonephritis (psgn) is an uncommon complication of either a strep throat or a streptococcal skin infection. it is classified as a type iii hypersensitivity reaction. symptoms of psgn develop within 10 days following a strep throat or 3 weeks following a gas skin infection. psgn involves inflammation of the kidney. symptoms include pale skin, lethargy, loss of appetite, headache, and dull back pain. clinical findings may include dark-colored urine, swelling of different parts of the body (edema), and high blood pressure. treatment of psgn consists of supportive care. pandas obsessive–compulsive disorder and tic disorders are hypothesized to arise in a subset of children as a result of a post-streptococcal autoimmune process. its potential effect was described in 1998 by the controversial hypothesis called pandas (pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections), a condition thought to be triggered by gabhs infections. the pandas hypothesis is unconfirmed and unsupported by data, and two new categories have been proposed: pans (pediatric acute-onset neuropsychiatric syndrome) and cans (childhood acute neuropsychiatric syndrome). the cans/pans hypotheses include different possible mechanisms underlying acute-onset neuropsychiatric conditions, but do not exclude gabhs infections as a cause in a subset of individuals. pandas, pans and cans are the focus of clinical and laboratory research but remain unproven.