Microbial Disease of the Skin and Eyes PDF

MICROBIAL DISEASE OF THE SKIN AND EYES PHMPLEC MICROBIAL DISEASE OF THE SKIN Often acidic STRUCTURE AND FUNCTION OF THE SKIN Membranes of the eyes are mechanically washed by The skin is a physical barrier against microor...

MICROBIAL DISEASE OF THE SKIN AND EYES PHMPLEC MICROBIAL DISEASE OF THE SKIN Often acidic STRUCTURE AND FUNCTION OF THE SKIN Membranes of the eyes are mechanically washed by The skin is a physical barrier against microorganisms. tears, and the lysozymes in tears destroys the cell Moist areas of the skin support larger populations of walls of certain bacteria bacteria than dry areas. NORMAL MICROBIOTA OF THE SKIN EPIDERMIS Microorganisms that live on skin are resistant to The outer portion of the skin Composed of several desiccation and high concentrations of salt. layer of epithelial cells Gram-positive cocci predominate on the skin. The outermost layer, the stratum corneum, consists Washing does not completely remove the normal of many rows of dead cells that contains a skin microbiota. waterproofing protein called keratin. Members of the genus Cutibacterium metabolize oil Effective physical barrier against mo from the oil glands and colonize hair follicles. Malassezia furfur yeast grows on oily secretions and DERMIS may be the cause of dandruff. The inner, relatively thick portion of skin The majority (90%) of skin microbiota consist of Composed mainly of connective tissue coagulase-negative Staphylococcus epidermidis. The hair follicles, sweat gland ducts, and oil gland ducts in the dermis provide passage- ways through TERMS FOR RASHES AND LESIONS which microorganisms can enter the skin and Vesicles: are small fluid-filled lesions penetrate deeper tissues. Bullae: are vesicles larger than 1 cm Macules: are flat, reddened lesions PERSPIRATION Papules: are raised lesions Provides moisture and some nutrients for microbial Pustules: are raised lesions containing pus growth Also contains salt which inhibits many micro- BACTERIAL DISEASES OF THE SKIN organisms STAPHYLOCOCCUS Contains the enzyme lysozyme, which is capable of are spherical gram-positive bacteria that form breaking down the cell walls of certain bacteria; and irregular grape-like clusters Divided into those that antimicrobial peptides. produce coagulase, and those that do not Namumuo yung yung bacteria kaya nagcacause ng Coagulase-positive bad smell sa kilikili S. aureus Coagulase-negative SEBUM S. epidermidis Secreted by oil glands Mannitol Salt Agar: Diferrentiation of Coagulase (+) A mixture of lipids (unsaturated fatty acids), and Coagulase (-) proteins, and salts Prevents skin and hair from drying out STAPHYLOCOCCUS EPIDERMIS Pag walang sebum → causes fungi Coagulase-negative Very common on the skin MUCOUS MEMBRANE AKA MUCOSA Generally pathogenic only when the skin barrier is Lines the body cavities that open to the exterior, i.e., broken or is invaded by medical procedures, e.g., gastrointestinal, respiratory, urinary, and genital insertion and removal of catheters into veins tracts Consists of sheets of tightly packed epithelial cells STAPHYLOCOCCUS AUREUS attached at their bases to a layer of extracellular Resident microbiota of the nasal passage material called basement membrane Forms golden-yellow colonies Many secretes mucus Almost all pathogenic strains of S. aureus produce Other mucosal cells have cilia, i.e., respiratory coagulase system Page 1|7 MICROBIAL DISEASE OF THE SKIN AND EYES PHMPLEC Some strains have impressive array of virulence Followed by shock and sometimes organ failure factors and means of evading host defenses (especially kidney failure) Localized infections (sties, pimples, and boils) result Caused by a staphylococcal toxin called TSST-1 from entry of S. aureus through openings in the skin. Sties: infection on the eyes: put hot pack STREPTOCOCCUS Streptococci are gram-positive spherical bacteria usually grows in chains. Prior to division, the individual cocci elongate on the axis of the chain, and then the cells divide. Cause a wide range of disease conditions including meningitis, pneumonia, sore throat, otitis media, endocarditis, puerperal fever, and even dental caries. Streptococci are classified according to their hemolytic enzymes (hemolysin) and cell wall antigens. Hemolytic activity ▪ Alpha, beta, gamma Cell wall antigen ▪ Group A to T CARBUNCLE STREPTOCOCCUS PYOGENES a furuncle which extensively damages neighboring Group A beta-hemolytic streptococci (GAS) produce tissues a number of virulence factors: M protein, Produce a hard, round deep inflammation of tissue deoxyribonuclease, streptokinases, and under the skin hyaluronidase. Patient can exhibit general illness with fever Cause severe and rapid tissue destruction. IMPETIGO ERYSIPELAS highly contagious skin infection caused by Skin erupts into reddish patches with raised margins Staphylococci. Can progress to local tissue destruction and even Characterized by isolated yellow pustules that enter the bloodstream causing sepsis become crusted. Usually appears first on the face “Mamaso” → Medication: Mupirocin (Bactroban) High fever is common TOXEMIA NECROTIZING FASCIITIS Toxemia occurs when toxins enter the bloodstream; Invasive group A streptococcal infection that staphylococcal toxemias include scalded skin destroys tissue and initially resembles TSS syndrome and toxic shock syndrome. “Flesh-eating bacteria” S. aureus produces exfoliative toxins: Causes by pyrogenic toxins, streptococcal M protein Exfoliatin A – causes localized, bullous types (act as superantigens) impetigo Associated with streptococcal TSS Exfoliatin B – causes the systemic infection of scalded skin syndrome PSEUDOMONAS AERUGINOSA Aerobic gram-negative rod SCALDED SKIN SYNDROME Resistant to many antibiotics and disinfectant Scalded skin syndrome is also characteristic of the Can survive in any moist environment, traces of late stages of toxic shock syndrome (TSS). unusual organic matter such as soap films, cap liner Potential life-threatening condition, fever, vomiting, adhesives and a sunburn-like rash Page 2|7 MICROBIAL DISEASE OF THE SKIN AND EYES PHMPLEC Diseases caused by P. aeruginosa include otitis VARICELLA-ZOSTER externa, respiratory infections, burn infections, and CHICKENPOX dermatitis is a relatively mild disease when contracted, as it Produces an endotoxin and several exotoxins usually is, in childhood. It is the initial infection of a herpesvirus MYCOBACTERIUM ULCERANS Varicellovirus. Causes deep-tissue ulceration or Buruli ulcer The species is varicella-zoster, or officially, human CUTIBACTERIUM ACNES herpesvirus (HHV-3). Formerly known as Propionibacterium acnes Its HHV-3 is transmitted by the respiratory route and is metabolic products (fatty acids) cause inflammatory localized in skin cells after about 2 weeks. acne Treatment: Comedonal (mild) acne HHV-3 can be treated with acyclovir. An Inflammatory (moderate) acne attenuated live vaccine is available. Nodular cystic (severe) acne The infected skin is vesicular for 3 to 4 days. Complications of chickenpox include encephalitis VIRAL DISEASES OF THE SKIN and Reye’s syndrome. WARTS Papillomaviruses cause skin cells to proliferate and SHINGLES produce a benign growth called a wart or papilloma. Characterized by a vesicular rash along the affected Warts are transmitted from one person to another cutaneous sensory nerves. by direct contact, even sexually. After chickenpox, the virus can remain latent in After infection, there is an incubation period of nerve cells and subsequently activate as shingles. several weeks before the warts appear. HERPES SIMPLEX Warts may regress spontaneously or be removed Herpes simplex viruses (HSV) can be separated into chemically or physically. two identifiable groups: Nonpharmacologic therapy HSV-1 (or human herpesvirus 1) Cryotherapy HSV-2 (or human herpesvirus 2) Electrodessication Acid treatment COLD SORES Laser Herpes simplex (HSV-1) infection of mucosal cells Pharmacologic Treatment Painful, short-lived vesicles that occur near the outer Salicylic acid red margin of the lips Podofilox HSV-1 Imiquimod transmitted primarily by skin contact, oral and Bleomycin respiratory routes. VARIOLA The virus remains latent in nerve cells, and cold also known as smallpox, is caused by an sores can recur when the virus is activated. orthopoxvirus known as smallpox virus (variola) HERPES ENCEPHALITIS Variola virus causes two types of skin infections: occurs when herpes simplex viruses (HSV-1 and HSV- variola major and variola minor. 2) infect the brain. Smallpox is transmitted by the respiratory route, and Treatment: the virus is moved to the skin via the bloodstream. Acyclovir has proven successful in treating The growth of the virus in the epidermal layers of herpes encephalitis. the skin causes lesions that becomes pustular after 10 days or so. MEASLES (RUBEOLA) Smallpox has been eradicated as a result of a Caused by measles virus vaccination effort by the World Health Organization. Page 3|7 MICROBIAL DISEASE OF THE SKIN AND EYES PHMPLEC An extremely contagious viral disease transmitted by Fungal infections or mycoses cause a wide range of the respiratory route diseases in humans. Vaccination (MMR vaccine) against measles provides 1. Superficial Infection effective long-term immunity 2. Cutaneous Infection MMR: Measles Mumps Rubella → binibigay sa bata 3. Subcutaneous Infection oara maging immune (vaccine) 4. Deep mycosis After the measles virus has incubated (10-12 days) in the upper respiratory tract, the following signs and SUPERFICIAL FUNGAL INFECTION PITYRIASIS VERSICOLOR symptoms appear. Common superficial mycosis, which is characterized Symptoms (like fever) similar to common by hypopigmentation or hyperpigmentation of skin cold. of the neck, shoulders, chest, and back Macular lesions appear on the skin. Due to Malassezia furfur which involves only the Koplik’s spots appear on the oral mucosa. superficial keratin layer Complications of measles include middle ear Tinea Versicolor: “An-an” infections, pneumonia, encephalitis, and secondary bacterial infections. BLACK PIEDRA How virus affect skin system A superficial mycosis due to Piedraia hortae which is High Oxygen Level manifested by a small firm black nodule involving High Pasteuralize the hair shaft. Makikita sa bunbunan ng baby RUBELLA German measles WHITE PIEDRA The rubella virus is transmitted by the respiratory Due to Trichosporon beigelii is characterized by a route and causes a red rash and light fever. soft, friable, beige nodule of the distal ends of hair Congenital rubella syndrome can affect a fetus when shafts. a woman contracts rubella during the first trimester of her pregnancy. TINEA NIGRA Most typically presents as a brown to black silver Vaccination with live, attenuated rubella virus nitrate-like stain on the palm of the hand or sole of provides immunity of unknown duration. the foot and and is caused by Phaeoannellomyces FIFTH DISEASE werneckii Also known as erythema infectiosum CUTANEOUS FUNGAL INFECTION Causes by human parvovirus B19 DERMATOPHYTES Characterized by symptoms similar to mild influenza Caused by fungi (Microsporum , Trichophyton and and a slapped-cheek facial rash that slowly fades Epidermophyton,) that colonize the outer layer of ROSEOLA the epidermis cause dermatomycoses Mild, very common childhood disease caused by Also known as ringworm, or tinea HHV-6 and HHV-7 These fungi grow on keratin-containing epidermis, such as hair, skin, and nails HAND-FOOT AND MOUT DISEASE An infection in young children in day care, preschool, and kindergarten Caused by several enteroviruses Spread by contact with mucous or saliva of an infected person Characterized by sore throat, then rashes appearing on hands, feet, mouth, tongue, and interior cheeks FUNGAL DISEASES OF THE SKIN AND NAILS Page 4|7 MICROBIAL DISEASE OF THE SKIN AND EYES PHMPLEC PARASITIC INFESTATION OF THE SKIN SCABIES Involves intense local itching Caused by a tiny mite Sarcoptes scabiei burrowing and laying eggs in the skin The mite is transmitted by intimate contact. Mite lives ~25 days, but by that time eggs have been laid and hatched Diagnosis Microscopic examination of skin scrapings Treatment Topical permethrin Oral ivermectin Diagnosis is based on the microscopic examination of skin scrapings or fungal culture. PEDICULOSIS Infestation by the head lice Pediculus humanus DERMATOMYCOSES capitis Cutaneous infections due to other fungi, the most Lice are easily transferred by head to-head contact common of which are Candida albicans Permethrin (Kwell): tx for crab lice/lice (kuto) C. albicans causes infections of mucous membranes Crab lice: makikita sa pubic hair: para matanggal and is a common cause of oral thrush and vaginitis. lagyan ng raw meat (?) yung area para matanggal Mag gargle si patient para hindi magkaron ng complete kasi may dugo dugo pa yung meat (?) C.albicans MICROBIAL DISEASE OF THE EYES SPOROTRICHOSIS STRUCTURE OF THE EYES Results from a soil fungus (Sporothrix schenckii that CONJUNCTIVA penetrates the skin through a wound The mucous membrane, made of epithelial cells, Common among gardeners or people working with lining the eyelid and covering the eyeball soil A transparent layer of living cells replacing the skin. Sporotichosis: gardener’s disease CONJUNCTIVITIS CHROMOBLASTOMYCOSIS Inflammation of the eye membranes (conjunctiva) Subcutaneous mycosis characterized by verrucoid Conjunctivitis is caused by several bacteria and can lesions of the skin be transmitted by improperly disinfected contact Most common causes are: lenses Fonsecaea pedrosoi (Pedroso’s disease) Conjunctivitis: “red eye” , “ sore eyes”, “pink eye” Fonsecaea compacta (Fonseca’s disease) Cladosporium carionii (Cladosporiosis) CORNEA Phialophora verrucose The transparent convex portion of the anterior eye. Chloroblastomycosis aka verrucous dermatitis KERATITIS MADURA FOOT (MYCETOMA) Inflammation of the cornea Chronic infection of the skin and underlying tissues by both bacteria (actinomycetoma) and fungi (eumycetoma). Suppurative and granulomatous subcutaneous mycosis Occur most often in farmers, hunter-gatherers, and field laborer Page 5|7 MICROBIAL DISEASE OF THE SKIN AND EYES PHMPLEC BACTERIAL INFECTION Caused by the same virus herpes simplex type 1 OPTHALMIA NEONATORUM (HSV-1) that causes cold sore and trigeminal Caused by the transmission of Neisseria gonorrheae neuralgia from an infected mother to an infant during its An infection of the cornea, causes deep ulcers passage through the birth canal. One of the causes of infectious blindness Causes suppurative conjunctivitis that results to Tx: Trifluridine corneal ulceration (may also lead to blindness) if not treated. ACANTHAMOEBA KERATITIS Treatment Painful corneal infection caused by Acanthamoeba protozoa Silver nitrate solution (1%) Can cause a serious form of keratitis as to require a Erythromycin corneal transplant or even removal of the eye Dilute povidone-iodine solution PARASITIC INFECTION INCLUSION CONJUNCTIVITIS Can be transmitted via water An infection caused by Chlamydia trachomatis to Contributing factors include inadequate disinfecting the conjunctiva procedures of contact lenses Transmitted to infants during birth and is Using homemade saline solutions transmitted in unchlorinated swimming water. Wearing contact lenses overnight Namumula yung mata dahil sa ihi and bacteria sa pool Wearing contact lenses while swimming Resolve spontaneously in a few weeks or months, Diagnosis is confirmed by the presence of but in rare cases it can lead to scarring of the cornea trophozoites and cysts in stained scrapings if the Treatment cornea. Treatment Tetracycline ophthalmic ointment Chlorhexidine 2% solution TRACHOMA Propamidine isethionate eye drops A serious eye infection, one of the major causes of Topical neomycin preventable blindness Caused by a certain serotype of C. trachomatis OTHER SIDE NOTES Conjunctivitis transmitted by hands, fomites, and Sore throat → Tonsilitis → Pharyngitis perhaps flies Co-amoxiclav: tx for tonsilitis Repeated infections cause inflammation leading to Silver Sulfa Diazine (Flamazine): tx for burn trichiasis. Comedones: White heads → oxidizes to Black Can be corrected surgically. heads Secondary infections by other bacterial pathogens Salicylic acid: tx for whiteheads (SA can reduce oils are also a factor in the disease. and causes dryness) Treatment Nodular cystic: makapal yung balat ng acne Oral azithromycin Papilloma virus aka HPV (Human Papilloma Virus) Bleomycin: antitumor drug, can also use for warts Improve sanitary practices and health Variola: DNA virus education Encephalitis: infection sa brain FUNGAL INFECTION Reye’s syndrome: nagkakaron ng rashes sa baby Fusarium, Candida, and Aspergillus fungi can infect kasi pinapainom ng aspirin (?) the eye especially in Africa and Asia. Shingles aka Herpes Zoster Oral Azithromycin: max is 1500 mg VIRAL INFECTION BCG (Bacillus Calmette Guerin): vaccinated to a HERPETIC KERATITIS pregnant para hindi magkaron ng TB (Tuberculosis) Deep mycosios: deep fungal infection Mucous membrane: epithelial cells Page 6|7 MICROBIAL DISEASE OF THE SKIN AND EYES PHMPLEC Page 7|7