NAME OF DISEASE:     Furunculosis - focal suppurative inflammation of the skin and
                                        subcutaneous tissue

                                        Folliculitis - hair follicle infection

                                        Hidradenitis - sweat gland infection

                                        Carbunculosis - a deep infection producing multiple, adjacent draining
                                        sinuses

                                        Scalded skin syndrome

ETIOLOGICAL AGENT:     Staphylococcus aureus

    Although there are a number of antigens on the surface of the staphylococcal cells, it is difficult to serologically type the cells. Instead phage typing is used. These are the hardiest of the non-sporeforming bacteria.

PATHOLOGY:

    Most adults are continuously exposed to S. aureus but overt infection occurs in 1 of 20 people each year. Predisposing factors include:

    1.     Hypogammaglobulinemia - congenital or acquired

    2.     Diabetes mellitus - high concentration of ketone bodies inhibits the intraleukocytic killing of
            engulfed S. aureus.

    3.     Chronic Granulomatous Disease - Neutrophils cannot make sufficient H₂O₂ to set off the
            oxidative pathway

    Pathology is the result of:

            1.     Toxin production

                    4 hemolysins

                    5 enterotoxins

                    1 leukocidin

                    Exfoliative toxin (plasmid-borne and in 5% of S. aureus)

                    Toxic shock toxin

            2.     Hemolysin production

                 a- dermonecrotic, causes aggregation of platelets and spasms of smooth muscle

                    ß - sphingomyelinase

                 d- detergent-like activity

                 g- weaker and not well characterized

            3.     Enzyme production

                    Coagulase

                    Staphylokinase

                    Hyaluronidase

                    Lipase

                    Proteinase

            4.     Envelope component production

                    Capsule

                    Murein - activates complement

                    Teichoic acid - activates complement, functions in adherence

                    Protein A - binds Fc terminus of IgG

DIAGNOSIS:

    The clinical manifestations of the skin may vary from a small pimple to a large furuncle or carbuncle (a deeply situated infection producing multiple adjacent draining skin sinuses) with rapid destruction of skin. Definitive diagnosis is by isolation of the organism from the site of infection or by demonstration of antibodies against staphylococcal teichoic acid antigens via simple agar gel diffusion or counterimmunoelectrophoresis (CIE). The hallmark of the disease is pus formation.

TREATMENT:

    Treat with penicillinase - resistant penicillins such as:

        Methicillin

        Oxacillin

        Nafcillin

        Cloxacillin

        Dicloxacillin

    If the organism is methicillin-resistant treat with:

        Vancomycin

        Clindamycin

        Gentamicin

        Cycloserine

        Fusidic acid

        Rifampin

Drain the wound via surgical incision.