Week 3: Upper Respiratory Infections

Hello everyone, this week we discussed upper respiratory infections.  One of the primary infections we discussed was pharyngitis, an infection characterized by pain, swelling, erythrema, gray-white exudate on the throat, fever and cervical lymphadenopathy.  The primary cause of bacterial pharyngitis is Streptococcus pyogenes.  I have decided to discuss Streptococcus pyogenes and its various clinical manifestations since the possible resulting conditions of an infection with Streptococcus pyogenes vary so greatly as far as clinical manifestations and severity of the conditions.  As previously mentioned, S. pyogenes can cause pharyngitis as a primary infection with such suppurative sequelae as sinusitis and otitis media.  Non-suppurative sequelae of S. pyogenes include Acute Rheumatic Fever and Acute Glomerular Nephritis.  Both of these conditions are immunological in nature.  ARF is believed to be autoimmune in nature and AGN is an immune complex issue.  Infections with Streptococcus pyogenes can also cause such cutaneous and soft tissue infections such as impetigo, erysipelas, and cellulitis.  Streptococcus pyogenes can also cause severe invasive syndromes such as severe scarlet fever, septicemia, severe pneumonia, streptococcal toxin shock-like syndrome and necrotizing fasciitis.  Necrotizing fasciitis is a deep seated infection of subcutaneous tissue involving progressive destruction of tissue, fascia, and fat.  This condition is associated with such streptococcal pyrogenic exotoxins as SPE A, B, and C.  Underlying conditions such as cancer, renal failure, diabetes, immunosuppression, peripheral vascular disease, skin trauma, burns, and skin infections can increase the risk of developing necrotizing fasciitis as a result of infection with Streptococcus pyogenes.  Treatment of necrotizing fasciitis includes antibiotic treatment, surgery, and amputation. 

            I have attached a video concerning necrotizing fasciitis that I found interesting.  Enjoy!