skin infections

Acne: microbe
Propionibacterium acnes
Acne: epidemiology
normal bacterial microbiota, up to 85% of adolescents suffer at some point
Acne: pathogenesis
hair follicle infection that spreads into surrounding tissue, generating an abscess
Acne: complications
skin disfigurement (scars)
Acne: treatment
tetracycline, blue light therapy, oral contraceptives, vitamin A derivitives, Accutane?
Acne: preventioon
decrease sebum accumulation by thorough personal hygiene and depress bacterial growth with topical peroxide-containing medications
Impetigo: microbe
Staphylococcus aureus and/or Streptococcus pyogenes
Impetigo: epidemiology
bacterial disease highly contagious in children
Impetigo: pathogenesis
superficial infection leads to formation of thin walled abscesses that look like blisters or "weeping" lesions with scabs
Impetigo: complications
blood poisoning (toxemia or septicemia)
Impetigo: treatment
bacitracin salve or other antimicrobial agents resistant to bacterial enzymes that destroy penicillins
Impetigo: prevention
personal hygiene, avoid contact with lesions on others
Furuncle (boil): microbe
Staphylcoccus aureus
Furuncle (boil):epidemioogy
normal microbiota in up to 30% normal humans
Furuncle (boil): pathogenesis
infected skin follicle leads to formation of an abscess
Furuncle (boil): complications
multiple abscesses (carbuncles), blood poisoning (toxemia) due to systemic distribution of toxin or bacteria, osteomyelitis
Furuncle (boil): treatment
"lance" abscess, treat with bacitracin, vancomycin, or other antimicrobial angents that are resistant to bacterial enzymes that destroy penicillins
Furuncle (boil): prevention
personal hygiene, avoid contact with boils on others
Necrotizing Fasciitis: microbe
Streptococcus pyogenes
Necrotizing Fasciitis: epidemiology
bacterium, there were 500-1500 cases in US in 1996, 20% fatal
Necrotizing Fasciitis: pathogenesis
rapidly spreading infection that leads to destruction of tissues at sites of infection
"flesh-eating disease"
Necrotizing Fasciitis: complications
formation of abscesses throughout the body and blood poisoning (toxemia or septicemia)
Necrotizing Fasciitis: treatment
penicillin, erythromycin, tetracycline, surgery
Necrotizing Fasciitis: prevention
personal hygiene
Candidiasis: microbe
Candida albicans
Candidiasis: epidemiology
dimorphic fungus is in normal microbiota, likelihood of developing disease is enhanced by chronic skin moisture, especially in immunosuppressed individuals
Candidiasis: pathogenesis
as candida grows on skin, induces a bright red inflammation, blister-like superficial lesions or more severe lesions all of which are related to hypersensitivity, sometimes around mouth
Candidiasis: complications
systemic infection, fulminating disease, death
Candidiasis treatment
Clotrimazole, miconazole, or nystatin for skin infection, oral ketoconazole for systemic infections
Candidiasis: prevention
avoid excess skin moisture, immunosuppression
Tineas (ringworm): microbe
Epidermophyton, microsporium, Trichophyton
Tineas (ringworm): epidemiology
dermatophytic fungi, prevalent in athletes
Tineas (ringworm): pathogenesis
superficial skin infection causes granulomas on head/scalp, groin, body, or foot
Tineas (ringworm): treatment
lamisil (terbinafine-HCl cream), shampoo with selenium, ketoconazole or itraconazole, griseofulvin for chronic infections
Tineas (ringworm): prevention
avoid lesions on others
Sporotrichosis: microbe
Sporothrix schenckii
Sporotrichosis: epidemiology
spores of this fungus in soil are transmitted by splinters, sphagnum moss, thorns, hay
Sporotrichosis: pathogenesis
skin lesions (painless pink bumps), develop at site of infection after 3-12 weeks, develop into ulcers that don't heal, enter lymphatics and move uparm
Sporotrichosis: complications
dissemination to lungs, joints, CNS, and can cause serious illness
KI, itraconazole, amphotericin B
Sporotrichosis: prevention
avoid contact with contaminated soil, splinters, thorns, etc
Warts (verruca vulgaris): microbe
Human Papilloma viruses (HPV)
Warts (verruca vulgaris): pathogenesis
skin disinfureation fom chronic benign tumors
Warts (verruca vulgaris): treatment
remove wart by surgery or by chemicals such as salicylic acid
warts (verruca vulgaris): prevention
avoid contact with warts on others
Herpes: microbe
Herpes Simplex Virus 1 (HSV-1)
Herpes: epidemiology
transmitted by direct contact
Herpes: pathogenesis
reurrent chronic lesions (blisters) on face, fingers, hands, become latent in local nerves and exhibits recurrence during periods of stress... "to creep"
Herpes: treatment
acyclovir shortens episode, slows reurrence, valtrex works better
Herpes: prevention
avoid contact with skin sores on others
Leprosy (Hansen's disease): microbe
Mycobacterium leprae
Leprosy (Hansen's diease): epidemiology
transmission unknown, about 600 cases known in US mostly by immigrants and travelers
Leprosy (Hansen's disease): pathogenesis
slowly developing lumpy or discolored lesions lead to sensory nerve damage and tissue destruction
Leprosy (Hansen's disease): complications
no awareness of cuts, burns, etc, leads to gangrene causing loss of digits or limbs, skin disfiguration, liver kidney and spleen damage causes death
Leprosy (Hansen's disease): treatment
long term multi drug therapy (MDT) using combo of dapsone clofazimine and rifamipin
Leprosy (Hansen's disease): prevention
avoid contact with skin lesions of lepers
Ebola Fever: microbe
Ebola virus
Ebola fever: epidemiology
transmitted by direct contact with infected blood, organs, secretions, semen, or contaminated needles, most prevalent in Africa
Ebola fever: pathogenesis
sudden malaise, fever, muscle pain, headache, sore throat followed by vomiting, diarrhea, rash, heavy bleeding for 2-21 days
ebola fever: complications
massive damage to kidney liver spleen, moderate damage to pancreas CNS heart, massive hemorrhage from all body orfices, leading to 50-90% death of cases
Ebola fever: treatment
TLC, systemic relief
Ebola Fever: Prevention
avoid contact with infected blood or body secretions
Gangrene (myonecrosis): microbe
Clostridium perfringens
Gangrene (myonecrosis): epidemiology
wound infected with endospores of bacterium from soil, clothing, etc
Gangrene (myonecrosis): pathogenesis
superficial infection leads to cellulitis then myonecrosis due to toxins
gangrene (myonecrosis): complications
death due to CNS damage by toxins
Gangrene (myonecrosis): treatment
debridement, penicillin, hyperbaric chamber (exposure to very high concentrations of oxygen)
gangrene (myonecrosis): prevention
early treatment
Tetanus: microbe
Clostridium tetani
Tetanus: epidemiology
endospores of this bacterium enter through animal bites, scratches, puncture wounds, fewer than 10 cases a year
Tetanus: pathogenesis
toxin (tetanospasmin) causes CNS damage (4-21 days)
tetanus: complications
respiratory failure causes death (70%)
tetanus: treatment
antitoxin, penicillin, valium, barbituates (minimize damage)
tetanus: prevention
antitoxin, vaccine (DPT vaccine and boosters)
Antrax: microbe
Bacillus antracis
Anthrax: epidemiology
an endopore-forming soil bacterium, this zoonotic disease primarily affects grazing animals such as cattle, sheep, and goats, but can be transmitted to humans by contact with the endospores by skin wounds or inhalation, disease considered good candidate for biological warfare
Anthrax: pathogenesis
as endospores germinate the vegetative bacterial cells begin to produce a necrotizing toxin that causes development of pustular lesions called eschars characterized by necrotic centers that will eventually be filled with black fluid
Anthrax: complications
fulminating septicemia that frequently leads to death, especially from the pulmonary form of the disease
Anthrax: treatment
penicillin... cipro
Antrax: prevention
vacine, avoid contact with endospore contaminated articles
Rabies: microbe
Rabies Virus
Rabies: epidemiology
transmitted via bites of infected animals, vampire legend?
Rabies: pathogenesis
CNS damage leads to death in 2-8 weeks
Rabies: treatment
vaccine (can prevent onset of disease after infection)
Plague: microbe
Yersinia Pestis
Plague: epidemiology
bacterium transmitte by rat fleas, endemic, 10-20 huan cases a year in US
Plague: pathogenesis
infects and kills macrophages, whole body damaged, causing fever and massive blood clotting, which leads to shock, which may cause death
Plague: treatment
streptomycin or tetracycline
Plague: prevention
vaccine, control rats and fleas, avoid contact
Lyme Disease: microbe
Borrelia burgdorferi
Lyme Disease: epidemioogy
spread by nymph stage of deer ticks, takes 36 hours to infect with enough bacteria, reservoirs are white tailed deer and white footed mice, 15,000 cases reported each year, most frequently tick borne disease
Lyme Disease: pathogenesis
expanding ring shaped rash (erythema migrans) at site of tick bite... acompanied by flu like symptoms and skin lesions, facial paralysis, forgetfulness, chronic systemic infection leads to arthritis, heart inflammation, neurological abnormals, nerve demyelination may lead to multiple sclerosis like symptoms
Lyme Disease: treatment
ceftin, penicillin, or tetracycline, long term therapy for chronic cases
Lyme Disease: prevention
vaccine, but removed, avoid tick bite and protect pets
Rocky Mountain Spotted Fever: microbe
Rickettsia rickettsii
Rocky Mountain Spotted Fever: epidemiology
bacterium transmitted by dog ticks, 600-80 new cases each year
Rocky Mountain Spotted Fever:pathogenesis
damage to blood vessels causes fever, accompanied by skin rash, headache, muscle pains
Rocky Mountain Spotted Fever: complications
damage to blood vessels throughout body leads to impaired function of kidneys, liver, lungs, CNS, and gastrointestinal tract, these can lead to death
Rocky Mountain Spotted Fever: treatment
tetracycline, or chlramphenicol plus symptomatic relief and supportive care for complications
Rocky Mountain Spotted Fever: prevention
vaccine for high risk people, avoid contact with ticks
Encephailtis: microbe
Encephalitis virus
Encephalitis: epidemiology
transmitted by mosquitos, reservoirs are other animals, most prevalent in Summer and fall, West Nile Fever is emerging
Encephalitis: pathogenesis
mosquito injects virus into bloodstream, virus replicates in CNS causing fever and headache, vomiting, stiff back and neck, drowsiness, tremors, loss of coordination, convulsions, seizures
Encephalitis: complications
coma and death
Encephalitis: treatment
TLC, management of symptoms and complications, treatment for West Nile Fever
Encephalitis: prevention
vaccines, mosquito repellent use, mosquito control
Dengue Fever: microbe
Dengue Fever Virus
Dengue Fever: epidemiology
transmitted by mosquitos, endemic in Africa, Carribean, Central and South America, Southeast Asia, and Australia, 100 cases per year
Dengue Fever: pathogenesis
mosquito injects virus into blodstream, this rarely fatal disease is characterized by sudden onset of high fever and rash together with severe headache and severe muscle, joint, and eye pain
Dengue Fever: complications
hemorrhagic fever with bleeding from gastrointestinal and other mucosal membrane orifices of body which can lead to shock and death
Dengue Fever: treatment
TLC, fluid replacement in hemorrhagic fever cases
Dengue Fever: prevention
Vaccines, mosquito repellent use, mosquito control
Yellow Fever: microbe
Yellow Fever Virus
Yellow Fever: epidemiology
transmitted by mosquitoes, occurs mostly in tropical and subtropical countries in Africa and South America where monkeys are reservoir
Yellow Fever: pathogenesis
mosquito injects virus into bloodstream where virus replicates in liver, intestines, and gingival tissues
Yellow Fever: complications
include death in up to 50% of cases
Yellow Fever: treatment
Yellow Fever: Prevention
Vaccine mosquito repellent use, mosquito control
Malaria: microbe
Malaria: epidemiology
protozoan is injected into bloodstream by female mosquitoes
350-500 million people infected, 1 million people die each year
Malaria: pathogenesis
infection of liver and erythrocytes, causes damage leading to chronic recurent chills followed by high fever, sweating, headache, nausea, splenomegaly
Malaria: complications
red blood cell loss causes anemia, black urine, accumulation of cell fragments in small blood vessels causes cerebral hemorrhage, kidney failure, heart attack, liver damage, death
Malaria: treatment
quinine derivatives
Malaria: prevention
vaccine, avoid contact with female mosquito
Afican Sleeping Sickness: microbe
Trypanosoma brucei rhodesiense or Trypanosoma brucei gambiense
African Sleeping Sickeness: epidemioogy
protozoan injected by tsetse fly in Africa, disease limits spread of people in equatorial Africa
African Sleeping Sickness: pathogenesis
tsetse fly bite painful and swollen, lesion like syphilitic chancere develops at site, systemic infection via bloodstream develops causing fever, severe headaches, paralysis, wasting, and coma (death)
African Sleeping Sickness: treatment
pentamidine and suramine used at 1st state, melarsoprol or eflornithine is 2nd stage
African Sleeping Sickness; prevention
avoid contact with tsetse fly
Schistosomiasis: microbe
Schistosoma spp.
Schistosomiasis: epidemiology
Fluke is transmitted by direct conact with its ccercarieae which are generate in certain species of snails aafter infection by miracidia, released from intestines, endemic
Schistosomiasis: pathogenesi
cercariae burrow through skin, infect blood stream, infect liver and mature into flukes and from eggs, respond by granulma formation and causes damage to lungs, bladder, liver, and intestines
Schistosomiasis: complications
chronic infection which causes ongoing liver damage
Schistosomiasis: treatment
praziquantel or oxiaminiquine
Schistosomiasis: prevention
avoid contact with water containing human sewage, snails especially in Asia, middle east, or Carribean islands