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Skin Disease. I. Skin A. Functions Protection Thermoregulation Waste removal 4. Water conservation. B. Anatomy 1. Epidermis 0.007 - 0.12mm thick 2. Dermis Supports the epidermis.
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I. Skin A. Functions • Protection • Thermoregulation • Waste removal 4. Water conservation
B. Anatomy 1. Epidermis 0.007 - 0.12mm thick 2. Dermis Supports the epidermis. Contains accessory organs (hair, blood vessels, nerves, sebum oil glands: Acene plugged sebum gland. Sebum secretion is important to microbial population, water, A.A. & lipids. pH 4.0 - 6.8 Microbial produce fatty acids which may inhibits potential diseases.
II. Normal Skin flora 1,000 organims/cm2. 10 million on scalp & armpits 3 Main groups 1. Diphtheroids Gram-positive Non-motile No spores Ex. Propionibacterium acene Anaerobic or aerotolerant. Grows within hair follicles. Growth inhanced by oily conditions. Produced F.A. - defend the skin from infections Excess - produceses abscesses, infect the liver, bone & heart (aids patients).
2. Staphylocci Gram-positive Cocci-clusters Ex. Staphylococcus epidermidis Prevents colonization by pathogen & maintain balance of skin flora. 3. Single Cell Fungi (Yeasts). Present in the human body from early childhood. Mala sezia - common genus. Harmless - Scaley fair rash, dandruff, Tinea versicolor - patchy scaliness (fair skin - dark patches, dark skin - light patches).
Review Name two functions of the skin. Why is it good for there to be natural floral on your skin? When do you have problems with the natural floral on your skin?
III. Skin Diseases caused by bacteria Most enter from a wound, but some may enter from the blood stream. A. Infection of a hair follicles 1. Folliculitis Symptoms - small red bumps developed at the site of hair follicle. Treatment - non, most of the time it clears up on its own. 2. Furuncles (boils) Symptoms - developed from a folliculitis, pus.
3. Carbuncles - large area of swelling Symptoms - pus, areas of thick skin, fever with sever infections. Treatment - Pus must be drained from a lesion (surgical) & anti staphylococcal medicine must be given. Squeezing bad - may spread to the brain or bone.
Review How can these diseases spread through out the skin? What is the most common type of treatment for these skin diseases?
B. Scalded Skin Syndrome (Ritters) Staphylococcus aureus Potential fatal in infants, up to 40%. Symptoms - 20% - 100% of the body is scalded red. Fever, malaise, painful around the nose & mouth. With in 48 hrs of redness, skin wrinkles & large blisters appear. Tender to the touch & feels like sand paper. Pathogens - toxins carried by the bloodstream which causes the skin to split below the epidermis. Treatment - placed in protective isolation, antibiotics, all dead skin is removed.
C. Rocky Mountain Spotted fever - gram negative – bacilli Symptoms - headache, pain in muscles, joints, & fever (flu-like). Days, rash appears on palms, wrists, & feet. Eventually spreads to the rest of the body. Bleeding in the mouth & nose. Effects the heart & kidney - result in shock & death if not caught early enough. Epidemiology - zoonosis - affect mainly animals, some humans West - wood tick East - dog tick
Pathogens - Rickettsial rickettsii, transmitted by ticks, mites, & lice. • Bite is painless, & symptoms don’t developed until 4 hours later. • Prevention - No Vaccines • Avoid tick infested areas. • Protective clothing. • Tick repellents. • Inspect body. • Remove tick without crushing, gasoline, whiskey. • Treat with antiseptic. • Treatment - Antibiotics - Tetracycline • Caught late the damage is irreversible. • With out treatment - fatal 20%, early 5%.
D. Lyme Disease Symptoms occurs in 3 stages 1st - days- weeks Skin rash (erythemachronicummigrans). Red bump to a size of 15 cm. Flu-like symptoms. 2nd 2 - 8 weeks after skin rash appears. Effects the electrical condition of the heart & nervous system. Dizzy spells & fainting. Paralysis of face, impairment in arms & legs 3rd 6 months after the rash appears. Joint pain & swelling.
Epidemiology - zoonosis - affect mainly animals, some humans. East - 80% of ticks infected. Pathogens – Borrelia burgdorferi - large spiral 11-25 um which is transmitted by deer ticks, Ixodes scapularis. Prevention Same as Rocky Mountain Spotted fever. Treatment Antibiotics – Doxycycline, Amoxicillin, & Eryhromycin
Review What causes Rocky Mountain Spotted fever & Lyme disease caused by? How are the transmitted? What is the best methods of dealing with these diseases? What should you do if you find a tick on you?
IV Skin Diseases caused by a virus A. Chicken Pox - Varicella, humans are the only host. Symptoms Rash, spots, bumps, blisters Lesions appear anywhere on the body (head, legs, arms, chest). 20% of the adults that get it develop pneumonia. Symptoms are more severe in children & adults. Major threat to newborns if mother develops it within 5 days of delivery & 2 days afterwards, mortality increases to 30%. Congenital varicella syndrome - underdeveloped limbs.
Pathogenesis 1. D.S. DNA Virus. 2. Enters the body via respiratory system. 3. Enters the sensory nerves, but conditions inside the nerve does not allow for full expression of the virus. Epidemiology 1. fewer than 200,000 /year 2. 90% of humans are infected by the age of 15. incubation is 10 - 21 days. 3. Infection can spread 1 - 2 days before rash & until lesions crust over. Prevention 1. 1995, live, attenuated varicella vaccine. 2. proven safe in over 2 million cases.
B. Shingles - Herpes zoster Symptoms Occur at any age, but are more common in advance age (weaken immunity). Enters the sensory nerves, but conditions inside the nerve does not allow for full expression of the virus. Rash lasts 1 - 2 weeks, but pain may last for several months. Spreads along the nerve path.
C. Rubeola (Measles) - paramyxovirus family • Worldwide reduction of measles due to vaccines. Symptoms Fever, runny nose, cough, swollen - red eyes. Rash after a few days, begins on the forehead & spreads to the rest of the body. Lasts for about 1 week. Complications arise from secondary infections due to weaken immunity - Staphylococcus aureus, Streptococcus pneumoniae. 5% leads to pneumonia.
Brain involvement 1/1000 Encephalitis - brain damage, retardation, deafness, epilepsy. Subacute sclerosing panencephalitis - 2 - 10 yrs after the measles, degeneration of the brain until death, 2 years. During pregnancy - miscarriage, premature labor. Pathogenesis RNA virus - paramyxovirus family. Enters through the respiratory route & spreads to the lymphatic system. Epidemiology Humans are the only host.
D. Rubella - German Measles Symptoms fever, cold, enlarge lymph symptoms. rash, pink spots. painful joints. Pathogenesis Enters through the respiratory system. Reproduces in the nasopharynx. Infected early in pregnancy - Congenial rubella syndrome - brain damage, deafness, heart defects. Infected in 1st 6 weeks of pregnancy, the 100% of the fetuses have detectable injuries.
Epidemiology Humans are the only natural host 10 - 15% of adult didn’t get it. 40% of rubella don’t get symptoms. Prevention Subcutaneous injection 12 -16 months of age. 95% get long lasting immunity. E. Warts - benign tumor (papillonia) from the Papillomaviruses. Some genital warts are associated with cervical & uterine cancer.
V. Fungi (mold)- Ringworm, Jock itch, Athlete’s foot. • Mold (Dermatophytes) invades hair, nails, & skin. • Symptoms None -> itching, rash, odor. Pathogenesis Normal skin is resistant to invasion. Moist skin are easier to invade. Keratinase - enzyme that breaks down keratin.
Prevention Cleanliness, dry-normal skin. Powder, open shoes. Changing of socks. Application of rubbing alcohol to nails. Treatment Over the counter medication - undecylenic acid.
Review What are the three classes of skin diseases?